Bump version to 5.1.10 for release

and publishing it, but we don't talk about that

.github/dependabot.yml

@@ -4,7 +4,7 @@ updates:
     directory: "/"
     schedule:
       interval: "monthly"
-  - package-ecosystem: "maven"
+  - package-ecosystem: "gradle"
     directory: "/"
     schedule:
       interval: "monthly"

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ on:
     tags-ignore:
       - '**'
     paths-ignore:
-      - resource-pack/**
+      - resource-pack/openinv-legibility-pack/**
   # Enable running CI via other Actions, i.e. for drafting releases and handling PRs.
   workflow_call:
 
@@ -21,14 +21,22 @@ jobs:
         with:
           distribution: 'temurin'
           java-version: '21'
-          cache: 'maven'
 
-      # Install Spigot dependencies if necessary.
-      - name: Install Spigot Dependencies
-        run: . scripts/install_spigot_dependencies.sh
+      # We can't use 'maven' prebuilt cache setup because it requires that the project have a pom file.
+      # BuildTools installs to Maven local if available, so it's easier to just rely on that.
+      - name: Cache Spigot dependency
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.m2/repository/org/spigotmc/
+          key: ${{ runner.os }}-buildtools-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: |
+            ${{ runner.os }}-buildtools-
 
-      - name: Build With Maven
-        run: mvn -e clean package -am -P all
+      - uses: gradle/actions/setup-gradle@v4
+
+      - name: Build with Gradle
+        run: ./gradlew clean build
 
       # Upload artifacts
       - name: Upload Distributable Jar
@@ -36,10 +44,4 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: dist
-          path: ./target/*.jar
-      - name: Upload API Jar
-        id: upload-api
-        uses: actions/upload-artifact@v4
-        with:
-          name: api
-          path: ./api/target/openinvapi*.jar
+          path: ./dist/*

.github/workflows/draft_release.yml

@@ -12,34 +12,25 @@ jobs:
     needs: [ run-ci ]
     runs-on: ubuntu-latest
     steps:
-      # Fetch all history - used to assemble changelog.
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-
-      - name: Set Release Variables
-        run: bash ./scripts/set_release_env.sh
-
       - name: Download build
         uses: actions/download-artifact@v4
         with:
           name: dist
           path: dist
 
-      - name: Package resource pack
-        run: |-
-          pushd resource-pack
-          zip -r ../dist/openinv-legibility-pack.zip .
-          popd
-
       - name: Create Release
         id: create-release
         uses: softprops/action-gh-release@v2.2.1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
-          name: ${{ env.VERSIONED_NAME }}
-          body: ${{ env.GENERATED_CHANGELOG }}
+          name: OpenInv ${{ env.VERSIONED_NAME }}
+          body: |-
+            ## Supported server versions
+            **Paper:** TODO VERSION, 1.21.4, 1.21.3, 1.21.1
+            **Spigot:** TODO VERSION
+            
+            TODO HELLO HUMAN, PRESS THE GENERATE CHANGELOG BUTTON PLEASE.
           draft: true
           prerelease: false
           files: ./dist/**

.github/workflows/external_release.yml

@@ -34,4 +34,4 @@ jobs:
           game_versions: "${{ env.CURSEFORGE_MINECRAFT_VERSIONS }}"
           release_type: release
           changelog_type: markdown
-          changelog: "${{ env.CURSEFORGE_CHANGELOG }}"
+          changelog: "${{ github.event.release.body }}"

.github/workflows/resource_pack_ci.yml

@@ -7,7 +7,7 @@ on:
     tags-ignore:
       - '**'
     paths:
-      - resource-pack/**
+      - resource-pack/openinv-legibility-pack/**
 
 jobs:
   build:
@@ -20,5 +20,5 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: openinv-legibility-pack
-          path: ./resource-pack/
+          path: ./resource-pack/openinv-legibility-pack/
           compression-level: 9

.gitignore

@@ -2,9 +2,12 @@
 **/.project
 **/.classpath
 **/.idea/
+**/.gradle/
 **.iml
 **/target/
 **/bin/
 **/out/
+**/build/
+**/dist/
 **/dependency-reduced-pom.xml
 **/pom.xml.versionsBackup

README.MD

@@ -36,22 +36,16 @@ The OpenInv API is available via [JitPack](https://jitpack.io/).
 ```xml
   <dependencies>
     <dependency>
-      <groupId>com.github.jikoo.OpenInv</groupId>
-      <artifactId>openinvapi</artifactId>
+      <groupId>com.github.Jikoo</groupId>
+      <artifactId>OpenInv</artifactId>
       <version>${openinv.version}</version>
     </dependency>
   </dependencies>
 ```
+Note that since JitPack only builds the API now, the "full" OpenInv jar on JitPack is actually the openinvapi artifact. This is a change from previous dependency declaration that I hope to revert.
 
 ### Compilation
-To compile, the relevant Spigot jars must be installed in the local repository.
-As OpenInv is compiled against Mojang's mappings, you must run BuildTools with the `--remapped` argument:  
-`java -jar BuildTools.jar --remapped --rev $serverVersion`  
-`$serverVersion` is the version of the server, i.e. `1.18.1`
+Execute the gradle wrapper:  
+`./gradlew build`
 
-To compile just the API, execute Maven as usual:  
-`mvn clean package`  
-
-To compile the full plugin, use the provided profile with `-P all`:  
-`mvn clean package -am -P all`  
-For more information, check out the [official Maven guide](http://maven.apache.org/guides/introduction/introduction-to-profiles.html).
+If you encounter issues with building the Spigot module, try running BuildTools manually.

addon/togglepersist/build.gradle.kts

@@ -0,0 +1,21 @@
+plugins {
+  `openinv-base`
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+}
+
+tasks.processResources {
+  expand("version" to version)
+}
+
+tasks.register<Copy>("distributeAddons") {
+  into(rootProject.layout.projectDirectory.dir("dist"))
+  from(tasks.jar)
+  rename("openinvtogglepersist.*\\.jar", "OITogglePersist.jar")
+}
+
+tasks.assemble {
+  dependsOn(tasks.named("distributeAddons"))
+}

addon/togglepersist/pom.xml

@@ -1,72 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-
-    <parent>
-        <artifactId>openinvparent</artifactId>
-        <groupId>com.lishid</groupId>
-        <relativePath>../../pom.xml</relativePath>
-        <version>5.1.5</version>
-    </parent>
-
-    <artifactId>openinvtogglepersist</artifactId>
-
-    <dependencies>
-        <dependency>
-            <artifactId>annotations</artifactId>
-            <groupId>org.jetbrains</groupId>
-        </dependency>
-        <dependency>
-            <groupId>org.spigotmc</groupId>
-            <artifactId>spigot-api</artifactId>
-        </dependency>
-        <dependency>
-            <artifactId>openinvapi</artifactId>
-            <groupId>com.lishid</groupId>
-            <scope>provided</scope>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <finalName>OITogglePersist</finalName>
-        <resources>
-            <resource>
-                <directory>src/main/resources</directory>
-                <filtering>true</filtering>
-            </resource>
-        </resources>
-
-        <plugins>
-            <plugin>
-                <artifactId>maven-compiler-plugin</artifactId>
-            </plugin>
-            <plugin>
-                <artifactId>maven-resources-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <id>copy-final-jar</id>
-                        <phase>package</phase>
-                        <goals>
-                            <goal>copy-resources</goal>
-                        </goals>
-                        <configuration>
-                            <outputDirectory>${project.parent.build.directory}</outputDirectory>
-                            <resources>
-                                <resource>
-                                    <directory>${project.build.directory}</directory>
-                                    <includes>
-                                        <include>${project.build.finalName}.jar</include>
-                                    </includes>
-                                </resource>
-                            </resources>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-
-    </build>
-
-</project>

addon/togglepersist/src/main/resources/plugin.yml

@@ -1,6 +1,6 @@
 name: OITogglePersist
 main: com.github.jikoo.openinv.togglepersist.TogglePersist
-version: ${project.version}
+version: ${version}
 author: Jikoo
 description: An OpenInv addon allowing /anycontainer and /silentcontainer to persist across sessions.
 api-version: "1.20"

api/build.gradle.kts

@@ -0,0 +1,14 @@
+plugins {
+  `openinv-base`
+  `maven-publish`
+}
+
+publishing {
+  publications {
+    create<MavenPublication>("jitpack") {
+      groupId = "com.github.Jikoo.OpenInv"
+      artifactId = "openinvapi"
+      from(components["java"])
+    }
+  }
+}

api/pom.xml

@@ -1,49 +0,0 @@
-<!--
-  ~ Copyright (C) 2011-2022 lishid. All rights reserved.
-  ~
-  ~ This program is free software: you can redistribute it and/or modify
-  ~ it under the terms of the GNU General Public License as published by
-  ~ the Free Software Foundation, version 3.
-  ~
-  ~ This program is distributed in the hope that it will be useful,
-  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
-  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-  ~ GNU General Public License for more details.
-  ~
-  ~ You should have received a copy of the GNU General Public License
-  ~ along with this program. If not, see <http://www.gnu.org/licenses/>.
-  -->
-
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <parent>
-    <artifactId>openinvparent</artifactId>
-    <groupId>com.lishid</groupId>
-    <version>5.1.5</version>
-  </parent>
-
-  <artifactId>openinvapi</artifactId>
-  <name>OpenInvAPI</name>
-
-  <dependencies>
-    <dependency>
-      <artifactId>annotations</artifactId>
-      <groupId>org.jetbrains</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>spigot-api</artifactId>
-      <groupId>org.spigotmc</groupId>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-      </plugin>
-    </plugins>
-  </build>
-
-</project>

build.gradle.kts

@@ -0,0 +1,27 @@
+plugins {
+  `java-library`
+  alias(libs.plugins.paperweight) apply false
+  alias(libs.plugins.shadow) apply false
+}
+
+// Set by Spigot module, used by Paper module to convert to Spigot's version of Mojang mappings.
+project.ext.set("craftbukkitPackage", "UNKNOWN")
+
+repositories {
+  maven("https://repo.papermc.io/repository/maven-public/")
+}
+
+// Allow submodules to target higher Java release versions.
+// Not currently necessary (as lowest supported version is in the 1.21 range)
+// but may become relevant in the future.
+java.disableAutoTargetJvm()
+
+// Task to delete ./dist where final files are output.
+tasks.register("cleanDist") {
+  delete("dist")
+}
+
+tasks.clean {
+  // Also delete distribution folder when cleaning.
+  dependsOn(tasks.named("cleanDist"))
+}

buildSrc/build.gradle.kts

@@ -0,0 +1,13 @@
+plugins {
+  `kotlin-dsl`
+}
+
+repositories {
+  gradlePluginPortal()
+  mavenCentral()
+}
+
+dependencies {
+  val libs = project.extensions.getByType(VersionCatalogsExtension::class.java).named("libs")
+  implementation(libs.findLibrary("specialsource").orElseThrow())
+}

buildSrc/settings.gradle.kts

@@ -0,0 +1,7 @@
+dependencyResolutionManagement {
+  versionCatalogs {
+    create("libs") {
+      from(files("../gradle/libs.versions.toml"))
+    }
+  }
+}

buildSrc/src/main/kotlin/com/github/jikoo/openinv/BuildToolsValueSource.kt

@@ -0,0 +1,98 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.provider.ValueSource
+import org.gradle.api.provider.ValueSourceParameters
+import org.gradle.process.ExecOperations
+import java.io.File
+import java.net.URI
+import java.nio.file.Files
+import javax.inject.Inject
+
+abstract class BuildToolsValueSource: ValueSource<File, BuildToolsValueSource.Parameters> {
+
+  @get:Inject
+  abstract val exec: ExecOperations
+
+  interface Parameters: ValueSourceParameters {
+    val mavenLocal: Property<File>
+    val workingDir: DirectoryProperty
+
+    val spigotVersion: Property<String>
+    val spigotRevision: Property<String>
+
+    val ignoreCached: Property<Boolean>
+
+    val javaHome: DirectoryProperty
+    val javaExecutable: Property<String>
+  }
+
+  override fun obtain(): File {
+    val version = parameters.spigotVersion.get()
+    val revision = parameters.spigotRevision.get()
+    val installLocation = getInstallLocation(version)
+    // If Spigot is already installed, don't reinstall.
+    if (!parameters.ignoreCached.get() && installLocation.exists()) {
+      println("Skipping Spigot installation, $version is present")
+      return installLocation
+    }
+
+    val buildTools = installBuildTools(parameters.workingDir.get().asFile)
+
+    println("Installing Spigot $version (rev $revision)")
+
+    exec.javaexec {
+      environment["JAVA_HOME"] = parameters.javaHome.get()
+      executable = parameters.javaExecutable.get()
+      workingDir = buildTools.parentFile
+      classpath(buildTools)
+      args = listOf("--nogui", "--rev", revision, "--remapped")
+    }.rethrowFailure()
+
+    // Mark work for delete.
+    cleanUp(buildTools.parentFile)
+
+    if (!installLocation.exists()) {
+      throw IllegalStateException(
+        "Failed to install Spigot $version from $revision. Does the revision point to a different version?")
+    }
+    return installLocation
+  }
+
+  private fun getInstallLocation(version: String): File {
+    return parameters.mavenLocal.get().resolve("org/spigotmc/spigot/$version/spigot-$version-remapped-mojang.jar")
+  }
+
+  private fun installBuildTools(workingDir: File): File {
+    val buildTools = workingDir.resolve("BuildTools.jar")
+    if (buildTools.exists()) {
+      return buildTools
+    }
+
+    workingDir.mkdirs()
+
+    val buildToolsUrl = "https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar"
+    println("Downloading $buildToolsUrl")
+    val stream = URI.create(buildToolsUrl).toURL().openStream()
+    Files.copy(stream, buildTools.toPath())
+    stream.close()
+
+    return buildTools
+  }
+
+  private fun cleanUp(dir: File) {
+    dir.deleteOnExit()
+    if (!dir.isDirectory) {
+      return
+    }
+
+    dir.listFiles()?.forEach {
+      if (it.isDirectory) {
+        cleanUp(it)
+      } else {
+        it.deleteOnExit()
+      }
+    }
+  }
+}

buildSrc/src/main/kotlin/com/github/jikoo/openinv/SpigotDependencyExtension.kt

@@ -0,0 +1,21 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.model.ObjectFactory
+import org.gradle.jvm.toolchain.JavaToolchainSpec
+
+abstract class SpigotDependencyExtension (
+  objects: ObjectFactory
+) {
+
+  val version = objects.property(String::class.java)
+  val revision = objects.property(String::class.java)
+    .convention(version.map {
+      it.replace("-R\\d+\\.\\d+-SNAPSHOT".toRegex(), "")
+    })
+  val configuration = objects.property(String::class.java)
+  val classifier = objects.property(String::class.java).convention("remapped-mojang")
+  val ext = objects.property(String::class.java)
+  val java = objects.property(JavaToolchainSpec::class.java)
+  val ignoreCached = objects.property(Boolean::class.java).convention(false)
+
+}

buildSrc/src/main/kotlin/com/github/jikoo/openinv/SpigotReobf.kt

@@ -0,0 +1,56 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.attributes.Bundling
+import org.gradle.api.attributes.Category
+import org.gradle.api.attributes.LibraryElements
+import org.gradle.api.attributes.Usage
+import org.gradle.jvm.tasks.Jar
+import org.gradle.kotlin.dsl.named
+import org.gradle.kotlin.dsl.register
+import java.nio.file.Paths
+
+class SpigotReobf: Plugin<Project> {
+
+  companion object {
+    const val ARTIFACT_CONFIG = "reobf"
+  }
+
+  override fun apply(target: Project) {
+    // Re-use extension from Spigot dependency declaration if available to reduce configuration requirements.
+    val spigotExt = target.dependencies.extensions.findByType(SpigotDependencyExtension::class.java)
+      ?: target.dependencies.extensions.create(
+        "spigot",
+        SpigotDependencyExtension::class.java,
+        target.objects
+      )
+
+    val mvnLocal = target.repositories.mavenLocal()
+
+    val reobfTask = target.tasks.register<SpigotReobfTask>("reobfTask") {
+      dependsOn(target.tasks.named("shadowJar"))
+      // ShadowJar extends Jar, so this should be a safe way to get the result without having
+      // to jump through hoops and shift around shadow declarations in the rest of the project.
+      inputFile.convention(target.tasks.named<Jar>("shadowJar").get().archiveFile)
+      spigotVersion.convention(spigotExt.version)
+      getMavenLocal().set(Paths.get(mvnLocal.url).toFile())
+    }
+
+    // Set up configuration for producing reobf jar.
+    target.configurations.consumable(ARTIFACT_CONFIG) {
+      attributes {
+        attribute(Category.CATEGORY_ATTRIBUTE, target.objects.named(Category.LIBRARY))
+        attribute(Usage.USAGE_ATTRIBUTE, target.objects.named(Usage.JAVA_RUNTIME))
+        attribute(Bundling.BUNDLING_ATTRIBUTE, target.objects.named(Bundling.EXTERNAL))
+        attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, target.objects.named(LibraryElements.JAR))
+      }
+    }
+
+    // Add artifact from reobf task.
+    target.artifacts {
+      add(ARTIFACT_CONFIG, reobfTask)
+    }
+  }
+
+}

buildSrc/src/main/kotlin/com/github/jikoo/openinv/SpigotReobfTask.kt

@@ -0,0 +1,85 @@
+package com.github.jikoo.openinv
+
+import net.md_5.specialsource.Jar
+import net.md_5.specialsource.JarMapping
+import net.md_5.specialsource.JarRemapper
+import net.md_5.specialsource.RemapperProcessor
+import net.md_5.specialsource.provider.JarProvider
+import net.md_5.specialsource.provider.JointProvider
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.Internal
+import org.gradle.api.tasks.TaskAction
+import java.io.File
+
+abstract class SpigotReobfTask: org.gradle.api.tasks.bundling.Jar() {
+
+  @get:Input
+  val spigotVersion: Property<String> = objectFactory.property(String::class.java)
+
+  @get:InputFile
+  val inputFile: RegularFileProperty = objectFactory.fileProperty()
+
+  @get:Input
+  val intermediaryClassifier: Property<String> = objectFactory.property(String::class.java).convention("mojang-mapped")
+
+  private val mavenLocal: Property<File> = objectFactory.property(File::class.java)
+
+  init {
+    archiveClassifier.convention(SpigotReobf.ARTIFACT_CONFIG)
+  }
+
+  @TaskAction
+  override fun copy() {
+    val spigotVer = spigotVersion.get()
+    val inFile = inputFile.get().asFile
+    val obfPath = inFile.resolveSibling(inFile.name.replace(".jar", "-${intermediaryClassifier.get()}.jar"))
+
+    // https://www.spigotmc.org/threads/510208/#post-4184317
+    val repo = mavenLocal.get()
+    val spigotDir = repo.resolve("org/spigotmc/spigot/$spigotVer/")
+    val mappingDir = repo.resolve("org/spigotmc/minecraft-server/$spigotVer/")
+
+    // Remap original Mojang-mapped jar to obfuscated intermediary
+    val mojangServer = spigotDir.resolve("spigot-$spigotVer-remapped-mojang.jar")
+    val mojangMappings = mappingDir.resolve("minecraft-server-$spigotVer-maps-mojang.txt")
+    remapPartial(mojangServer, mojangMappings, inFile, obfPath, true)
+
+    // Remap obfuscated intermediary jar to Spigot and replace original
+    val obfServer = spigotDir.resolve("spigot-$spigotVer-remapped-obf.jar")
+    val spigotMappings = mappingDir.resolve("minecraft-server-$spigotVer-maps-spigot.csrg")
+    remapPartial(obfServer, spigotMappings, obfPath, archiveFile.get().asFile, false)
+  }
+
+  private fun remapPartial(server: File, mapping: File, input: File, output: File, reverse: Boolean) {
+    val jarMapping = JarMapping()
+    jarMapping.loadMappings(mapping.path, reverse, false, null, null)
+
+    val inheritance = JointProvider()
+    jarMapping.setFallbackInheritanceProvider(inheritance)
+
+    // Equivalent of --live with server jar on classpath.
+    val serverJar = Jar.init(server)
+    inheritance.add(JarProvider(serverJar))
+
+    val inputJar = Jar.init(input)
+    inheritance.add(JarProvider(inputJar))
+
+    // Remap reflective access.
+    val preprocessor = RemapperProcessor(null, jarMapping, null)
+
+    val remapper = JarRemapper(preprocessor, jarMapping, null)
+    remapper.remapJar(inputJar, output, emptySet())
+
+    serverJar.close()
+    inputJar.close()
+  }
+
+  @Internal
+  internal fun getMavenLocal(): Property<File> {
+    return mavenLocal
+  }
+
+}

buildSrc/src/main/kotlin/com/github/jikoo/openinv/SpigotSetup.kt

@@ -0,0 +1,59 @@
+package com.github.jikoo.openinv
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.plugins.JavaPluginExtension
+import org.gradle.jvm.toolchain.JavaToolchainService
+import org.gradle.kotlin.dsl.create
+import java.nio.file.Paths
+import javax.inject.Inject
+
+abstract class SpigotSetup: Plugin<Project> {
+
+  @get:Inject
+  abstract val javaToolchainService: JavaToolchainService
+
+  override fun apply(target: Project) {
+    target.plugins.apply("java")
+
+    // Set up extension for configuring Spigot dependency.
+    val spigotExt = target.dependencies.extensions.findByType(SpigotDependencyExtension::class.java)
+      ?: target.dependencies.extensions.create(
+        "spigot",
+        SpigotDependencyExtension::class.java,
+        target.objects
+      )
+
+    val mvnLocal = target.repositories.mavenLocal()
+
+    target.afterEvaluate {
+      // Get Java requirements, defaulting to version used for compilation.
+      spigotExt.java.convention(target.extensions.getByType(JavaPluginExtension::class.java).toolchain)
+      val launcher = javaToolchainService.launcherFor(spigotExt.java.get()).get()
+
+      // Install Spigot with BuildTools.
+      target.providers.of(BuildToolsValueSource::class.java) {
+        parameters {
+          mavenLocal.set(Paths.get(mvnLocal.url).toFile())
+          workingDir.set(target.layout.buildDirectory.dir("tmp/buildtools"))
+          spigotVersion.set(spigotExt.version)
+          spigotRevision.set(spigotExt.revision)
+          ignoreCached.set(spigotExt.ignoreCached)
+          javaHome.set(launcher.metadata.installationPath)
+          javaExecutable.set(launcher.executablePath.asFile.path)
+        }
+      }.get()
+
+      // Add Spigot dependency.
+      val dependency = target.dependencies.create(
+        "org.spigotmc",
+        "spigot",
+        spigotExt.version.get(),
+        spigotExt.configuration.orNull,
+        spigotExt.classifier.orNull,
+        spigotExt.ext.orNull)
+      target.dependencies.add("compileOnly", dependency)
+    }
+  }
+
+}

buildSrc/src/main/kotlin/openinv-base.gradle.kts

@@ -0,0 +1,34 @@
+import org.gradle.jvm.toolchain.JavaLanguageVersion
+import org.gradle.kotlin.dsl.maven
+import org.gradle.kotlin.dsl.repositories
+import org.gradle.kotlin.dsl.dependencies
+
+plugins {
+  `java-library`
+}
+
+java {
+  toolchain.languageVersion = JavaLanguageVersion.of(21)
+}
+
+repositories {
+  mavenCentral()
+  maven("https://repo.papermc.io/repository/maven-public/")
+  maven("https://hub.spigotmc.org/nexus/content/groups/public/")
+}
+
+dependencies {
+  val libs = versionCatalogs.named("libs")
+  compileOnly(libs.findLibrary("annotations").orElseThrow())
+  compileOnly(libs.findLibrary("spigotapi").orElseThrow())
+}
+
+tasks {
+  withType<JavaCompile>().configureEach {
+    options.release = 21
+    options.encoding = Charsets.UTF_8.name()
+  }
+  withType<Javadoc>().configureEach {
+    options.encoding = Charsets.UTF_8.name()
+  }
+}

common/build.gradle.kts

@@ -0,0 +1,7 @@
+plugins {
+  `openinv-base`
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+}

common/pom.xml

@@ -1,30 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-
-    <parent>
-        <groupId>com.lishid</groupId>
-        <artifactId>openinvparent</artifactId>
-        <version>5.1.5</version>
-    </parent>
-
-    <artifactId>openinvcommon</artifactId>
-
-    <dependencies>
-        <dependency>
-            <artifactId>annotations</artifactId>
-            <groupId>org.jetbrains</groupId>
-        </dependency>
-        <dependency>
-            <groupId>org.spigotmc</groupId>
-            <artifactId>spigot-api</artifactId>
-        </dependency>
-        <dependency>
-            <artifactId>openinvapi</artifactId>
-            <groupId>com.lishid</groupId>
-        </dependency>
-    </dependencies>
-
-</project>

gradle.properties

@@ -0,0 +1,9 @@
+# Project meta
+group=com.lishid.openinv
+version=5.1.10
+description=A Bukkit plugin for opening normally-inaccessible inventories.
+
+# Gradle configuration
+org.gradle.parallel=true
+org.gradle.caching=true
+org.gradle.configuration-cache=true

gradle/libs.versions.toml

@@ -0,0 +1,19 @@
+[versions]
+spigotapi = "1.21.5-R0.1-SNAPSHOT"
+specialsource = "1.11.5"
+planarwrappers = "3.3.0"
+annotations = "26.0.2"
+paperweight = "2.0.0-beta.16"
+shadow = "8.3.6"
+folia-scheduler-wrapper = "v0.0.3"
+
+[libraries]
+spigotapi = { module = "org.spigotmc:spigot-api", version.ref = "spigotapi" }
+specialsource = { module = "net.md-5:SpecialSource", version.ref = "specialsource" }
+planarwrappers = { module = "com.github.jikoo:planarwrappers", version.ref = "planarwrappers" }
+annotations = { module = "org.jetbrains:annotations", version.ref = "annotations" }
+folia-scheduler-wrapper = { module = "com.github.NahuLD.folia-scheduler-wrapper:folia-scheduler-wrapper", version.ref = "folia-scheduler-wrapper" }
+
+[plugins]
+paperweight = { id = "io.papermc.paperweight.userdev", version.ref = "paperweight" }
+shadow = { id = "com.gradleup.shadow", version.ref = "shadow" }

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

internal/common/build.gradle.kts

@@ -0,0 +1,60 @@
+import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
+
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+//tasks {
+//  withType<JavaCompile> {
+//    // OpenPlayer unchecked warning is due to superclass' messy inheritance and legacy methods.
+//    options.compilerArgs.add("-Xlint:unchecked")
+//    // PlayerManager uses "deprecated" method matching vanilla to support legacy save data.
+//    // While vanilla still feels that it is appropriate to use in the load process, we will too.
+//    options.compilerArgs.add("-Xlint:deprecation")
+//  }
+//}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+
+  paperweight.paperDevBundle("1.21.5-R0.1-SNAPSHOT")
+}
+
+val spigot = tasks.register<ShadowJar>("spigotRelocations") {
+  dependsOn(tasks.jar)
+  from(sourceSets.main.get().output)
+  relocate("com.lishid.openinv.internal.common", "com.lishid.openinv.internal.reobf")
+  relocate("org.bukkit.craftbukkit", "org.bukkit.craftbukkit.${rootProject.extra["craftbukkitPackage"]}")
+  archiveClassifier = "spigot"
+}
+
+configurations {
+  consumable("spigotRelocated") {
+    attributes {
+      attribute(Category.CATEGORY_ATTRIBUTE, objects.named(Category.LIBRARY))
+      attribute(Usage.USAGE_ATTRIBUTE, objects.named(Usage.JAVA_RUNTIME))
+      attribute(Bundling.BUNDLING_ATTRIBUTE, objects.named(Bundling.EXTERNAL))
+      attribute(LibraryElements.LIBRARY_ELEMENTS_ATTRIBUTE, objects.named(LibraryElements.JAR))
+    }
+  }
+}
+
+artifacts {
+  add("spigotRelocated", spigot)
+}

internal/common/src/main/java/com/lishid/openinv/internal/common/InternalAccessor.java

@@ -1,19 +1,19 @@
-package com.lishid.openinv.internal.v1_21_R3;
+package com.lishid.openinv.internal.common;
 
 import com.lishid.openinv.internal.Accessor;
 import com.lishid.openinv.internal.IAnySilentContainer;
 import com.lishid.openinv.internal.ISpecialEnderChest;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.ISpecialPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R3.container.AnySilentContainer;
-import com.lishid.openinv.internal.v1_21_R3.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R3.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R3.container.Placeholders;
-import com.lishid.openinv.internal.v1_21_R3.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.AnySilentContainer;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.slot.placeholder.PlaceholderLoader;
+import com.lishid.openinv.internal.common.player.PlayerManager;
 import com.lishid.openinv.util.lang.LanguageManager;
 import net.minecraft.world.Container;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
 import org.jetbrains.annotations.NotNull;
@@ -24,7 +24,7 @@ import java.util.logging.Logger;
 
 public class InternalAccessor implements Accessor {
 
-  private final @NotNull Logger logger;
+  protected final @NotNull Logger logger;
   private final @NotNull PlayerManager manager;
   private final @NotNull AnySilentContainer anySilentContainer;
 
@@ -69,12 +69,11 @@ public class InternalAccessor implements Accessor {
   @Override
   public void reload(@NotNull ConfigurationSection config) {
     ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
-    if (placeholders != null) {
-      try {
-        Placeholders.load(placeholders);
-      } catch (Exception e) {
-        logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
-      }
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new PlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
     }
   }
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/AnySilentContainer.java

@@ -14,11 +14,11 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-package com.lishid.openinv.internal.v1_21_R2.container;
+package com.lishid.openinv.internal.common.container;
 
 import com.lishid.openinv.internal.AnySilentContainerBase;
-import com.lishid.openinv.internal.v1_21_R2.container.menu.OpenChestMenu;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.menu.OpenChestMenu;
+import com.lishid.openinv.internal.common.player.PlayerManager;
 import com.lishid.openinv.util.ReflectionHelper;
 import com.lishid.openinv.util.lang.LanguageManager;
 import net.minecraft.core.BlockPos;
@@ -61,10 +61,10 @@ public class AnySilentContainer extends AnySilentContainerBase {
         this.lang = lang;
         try {
             try {
-                this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("b");
+                this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("gameModeForPlayer");
                 this.serverPlayerGameModeGameType.setAccessible(true);
             } catch (NoSuchFieldException e) {
-                logger.warning("ServerPlayerGameMode#gameModeForPlayer's obfuscated name has changed!");
+                logger.warning("The field ServerPlayerGameMode#gameModeForPlayer is no longer present!");
                 logger.warning("Please report this at https://github.com/Jikoo/OpenInv/issues");
                 logger.warning("Attempting to fall through using reflection. Please verify that SilentContainer does not fail.");
                 // N.B. gameModeForPlayer is (for now) declared before previousGameModeForPlayer so silent shouldn't break.

internal/common/src/main/java/com/lishid/openinv/internal/common/container/OpenEnderChest.java

@@ -1,9 +1,9 @@
-package com.lishid.openinv.internal.v1_21_R3.container;
+package com.lishid.openinv.internal.common.container;
 
 import com.lishid.openinv.internal.ISpecialEnderChest;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R3.container.menu.OpenEnderChestMenu;
-import com.lishid.openinv.internal.v1_21_R3.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.menu.OpenEnderChestMenu;
+import com.lishid.openinv.internal.common.player.PlayerManager;
 import net.minecraft.core.NonNullList;
 import net.minecraft.network.chat.Component;
 import net.minecraft.server.level.ServerPlayer;
@@ -15,8 +15,8 @@ import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.inventory.StackedContentsCompatible;
 import net.minecraft.world.item.ItemStack;
 import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R3.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftInventory;
+import org.bukkit.craftbukkit.entity.CraftHumanEntity;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
@@ -90,12 +90,12 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
   }
 
   @Override
-  public ItemStack getItem(int index) {
+  public @NotNull ItemStack getItem(int index) {
     return index >= 0 && index < items.size() ? items.get(index) : ItemStack.EMPTY;
   }
 
   @Override
-  public ItemStack removeItem(int index, int amount) {
+  public @NotNull ItemStack removeItem(int index, int amount) {
     ItemStack itemstack = ContainerHelper.removeItem(items, index, amount);
 
     if (!itemstack.isEmpty()) {
@@ -106,12 +106,12 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
   }
 
   @Override
-  public ItemStack removeItemNoUpdate(int index) {
+  public @NotNull ItemStack removeItemNoUpdate(int index) {
     return index >= 0 && index < items.size() ? items.set(index, ItemStack.EMPTY) : ItemStack.EMPTY;
   }
 
   @Override
-  public void setItem(int index, ItemStack itemStack) {
+  public void setItem(int index, @NotNull ItemStack itemStack) {
     if (index >= 0 && index < items.size()) {
       items.set(index, itemStack);
     }
@@ -128,27 +128,27 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
   }
 
   @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
     return true;
   }
 
   @Override
-  public List<ItemStack> getContents() {
+  public @NotNull List<ItemStack> getContents() {
     return items;
   }
 
   @Override
-  public void onOpen(CraftHumanEntity craftHumanEntity) {
+  public void onOpen(@NotNull CraftHumanEntity craftHumanEntity) {
     transaction.add(craftHumanEntity);
   }
 
   @Override
-  public void onClose(CraftHumanEntity craftHumanEntity) {
+  public void onClose(@NotNull CraftHumanEntity craftHumanEntity) {
     transaction.remove(craftHumanEntity);
   }
 
   @Override
-  public List<HumanEntity> getViewers() {
+  public @NotNull List<HumanEntity> getViewers() {
     return transaction;
   }
 
@@ -174,7 +174,7 @@ public class OpenEnderChest implements Container, StackedContentsCompatible, Int
   }
 
   @Override
-  public void fillStackedContents(StackedItemContents stackedContents) {
+  public void fillStackedContents(@NotNull StackedItemContents stackedContents) {
     for (ItemStack itemstack : items) {
       stackedContents.accountStack(itemstack);
     }

internal/common/src/main/java/com/lishid/openinv/internal/common/container/OpenInventory.java

@@ -1,20 +1,22 @@
-package com.lishid.openinv.internal.v1_21_R3.container;
+package com.lishid.openinv.internal.common.container;
 
 import com.lishid.openinv.internal.ISpecialPlayerInventory;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R3.container.bukkit.OpenPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R3.container.menu.OpenInventoryMenu;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.Content;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentCrafting;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentCraftingResult;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentCursor;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentList;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentOffHand;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentViewOnly;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.SlotViewOnly;
-import com.lishid.openinv.internal.v1_21_R3.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.bukkit.OpenPlayerInventory;
+import com.lishid.openinv.internal.common.container.menu.OpenInventoryMenu;
+import com.lishid.openinv.internal.common.container.slot.Content;
+import com.lishid.openinv.internal.common.container.slot.ContentCrafting;
+import com.lishid.openinv.internal.common.container.slot.ContentCraftingResult;
+import com.lishid.openinv.internal.common.container.slot.ContentCursor;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.ContentEquipment;
+import com.lishid.openinv.internal.common.container.slot.ContentList;
+import com.lishid.openinv.internal.common.container.slot.ContentOffHand;
+import com.lishid.openinv.internal.common.container.slot.ContentViewOnly;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.PlayerManager;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import net.minecraft.ChatFormatting;
 import net.minecraft.core.NonNullList;
 import net.minecraft.network.chat.Component;
@@ -29,21 +31,23 @@ import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
 import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R3.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftInventory;
+import org.bukkit.craftbukkit.entity.CraftHumanEntity;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
+import java.util.Map;
 
 public class OpenInventory implements Container, InternalOwned<ServerPlayer>, ISpecialPlayerInventory {
 
-  private final List<Content> slots;
+  protected final List<Content> slots;
   private final int size;
-  private ServerPlayer owner;
+  protected ServerPlayer owner;
   private int maxStackSize = 99;
   private CraftInventory bukkitEntity;
   public List<HumanEntity> transaction = new ArrayList<>();
@@ -59,15 +63,14 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
     setupSlots();
   }
 
-  private void setupSlots() {
+  protected void setupSlots() {
     // Top of inventory: Regular contents.
     int nextIndex = addMainInventory();
 
     // If inventory is expected size, we can arrange slots to be pretty.
     Inventory ownerInv = owner.getInventory();
-    if (ownerInv.items.size() == 36
-        && ownerInv.armor.size() == 4
-        && ownerInv.offhand.size() == 1
+    if (ownerInv.getNonEquipmentItems().size() == 36
+        && Inventory.EQUIPMENT_SLOT_MAPPING.size() == 5
         && owner.inventoryMenu.getCraftSlots().getContainerSize() == 4) {
       // Armor slots: Bottom left.
       addArmor(36);
@@ -94,7 +97,7 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
   }
 
   private int addMainInventory() {
-    int listSize = owner.getInventory().items.size();
+    int listSize = owner.getInventory().getNonEquipmentItems().size();
     // Hotbar slots are 0-8. We want those to appear on the bottom of the inventory like a normal player inventory,
     // so everything else needs to move up a row.
     int hotbarDiff = listSize - 9;
@@ -112,7 +115,7 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
       slots.set(localIndex, new ContentList(owner, invIndex, type) {
         @Override
         public void setHolder(@NotNull ServerPlayer holder) {
-          items = holder.getInventory().items;
+          items = holder.getInventory().getNonEquipmentItems();
         }
       });
     }
@@ -120,50 +123,36 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
   }
 
   private int addArmor(int startIndex) {
-    int listSize = owner.getInventory().armor.size();
-
-    for (int i = 0; i < listSize; ++i) {
-      // Armor slots go bottom to top; boots are slot 0, helmet is slot 3.
-      // Since we have to display horizontally due to space restrictions,
-      // making the left side the "top" is more user-friendly.
-      int armorIndex;
-      EquipmentSlot slot;
-      switch (i) {
-        case 3 -> {
-          armorIndex = 0;
-          slot = EquipmentSlot.FEET;
-        }
-        case 2 -> {
-          armorIndex = 1;
-          slot = EquipmentSlot.LEGS;
-        }
-        case 1 -> {
-          armorIndex = 2;
-          slot = EquipmentSlot.CHEST;
-        }
-        case 0 -> {
-          armorIndex = 3;
-          slot = EquipmentSlot.HEAD;
-        }
-        default -> {
-          // In the event that new armor slots are added, they can be placed at the end.
-          armorIndex = i;
-          slot = EquipmentSlot.MAINHAND;
-        }
+    // Armor slots go bottom to top; boots are first and helmet is last.
+    // Since we have to display horizontally due to space restrictions,
+    // making the left side the "top" is more user-friendly.
+    EquipmentSlot[] sorted = Inventory.EQUIPMENT_SLOT_MAPPING.int2ObjectEntrySet()
+        .stream()
+        .sorted(Comparator.comparingInt(Int2ObjectMap.Entry::getIntKey))
+        .map(Map.Entry::getValue)
+        .toArray(EquipmentSlot[]::new);
+    int localIndex = 0;
+    for (int i = sorted.length - 1; i >= 0; --i) {
+      // Skip off-hand, handled separately.
+      if (sorted[i] == EquipmentSlot.OFFHAND) {
+        continue;
       }
 
-      slots.set(startIndex + i, new ContentEquipment(owner, armorIndex, slot));
+      slots.set(startIndex + localIndex, new ContentEquipment(owner, sorted[i]));
+      ++localIndex;
     }
 
-    return startIndex + listSize;
+    return startIndex + localIndex;
   }
 
   private int addOffHand(int startIndex) {
-    int listSize = owner.getInventory().offhand.size();
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      slots.set(startIndex + localIndex, new ContentOffHand(owner, localIndex));
+    // No off-hand?
+    if (!Inventory.EQUIPMENT_SLOT_MAPPING.containsValue(EquipmentSlot.OFFHAND)) {
+      return startIndex;
     }
-    return startIndex + listSize;
+
+    slots.set(startIndex, new ContentOffHand(owner));
+    return startIndex + 1;
   }
 
   private int addCrafting(int startIndex, boolean pretty) {
@@ -191,12 +180,16 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
           };
         }
       });
-      slots.set(startIndex + 11, new ContentCraftingResult(owner));
+      slots.set(startIndex + 11, getCraftingResult(owner));
     }
 
     return startIndex + listSize;
   }
 
+  protected Content getCraftingResult(@NotNull ServerPlayer serverPlayer) {
+    return new ContentCraftingResult(serverPlayer);
+  }
+
   public Slot getMenuSlot(int index, int x, int y) {
     return slots.get(index).asSlot(this, index, x, y);
   }
@@ -275,22 +268,22 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
   }
 
   @Override
-  public ItemStack getItem(int index) {
+  public @NotNull ItemStack getItem(int index) {
     return slots.get(index).get();
   }
 
   @Override
-  public ItemStack removeItem(int index, int amount) {
+  public @NotNull ItemStack removeItem(int index, int amount) {
     return slots.get(index).removePartial(amount);
   }
 
   @Override
-  public ItemStack removeItemNoUpdate(int index) {
+  public @NotNull ItemStack removeItemNoUpdate(int index) {
     return slots.get(index).remove();
   }
 
   @Override
-  public void setItem(int index, ItemStack itemStack) {
+  public void setItem(int index, @NotNull ItemStack itemStack) {
     slots.get(index).set(itemStack);
   }
 
@@ -308,12 +301,12 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
   public void setChanged() {}
 
   @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
     return true;
   }
 
   @Override
-  public List<ItemStack> getContents() {
+  public @NotNull List<ItemStack> getContents() {
     NonNullList<ItemStack> contents = NonNullList.withSize(getContainerSize(), ItemStack.EMPTY);
     for (int i = 0; i < getContainerSize(); ++i) {
       contents.set(i, getItem(i));
@@ -322,22 +315,22 @@ public class OpenInventory implements Container, InternalOwned<ServerPlayer>, IS
   }
 
   @Override
-  public void onOpen(CraftHumanEntity viewer) {
+  public void onOpen(@NotNull CraftHumanEntity viewer) {
     transaction.add(viewer);
   }
 
   @Override
-  public void onClose(CraftHumanEntity viewer) {
+  public void onClose(@NotNull CraftHumanEntity viewer) {
     transaction.remove(viewer);
   }
 
   @Override
-  public List<HumanEntity> getViewers() {
+  public @NotNull List<HumanEntity> getViewers() {
     return transaction;
   }
 
   @Override
-  public org.bukkit.entity.Player getOwner() {
+  public @NotNull org.bukkit.entity.Player getOwner() {
     return owner.getBukkitEntity();
   }
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/bukkit/OpenDummyInventory.java

@@ -1,9 +1,9 @@
-package com.lishid.openinv.internal.v1_21_R2.container.bukkit;
+package com.lishid.openinv.internal.common.container.bukkit;
 
 import com.lishid.openinv.internal.ViewOnly;
 import net.minecraft.world.Container;
 import org.bukkit.Material;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
@@ -62,7 +62,7 @@ public class OpenDummyInventory extends CraftInventory implements ViewOnly {
   }
 
   @Override
-  public ItemStack[] getContents() {
+  public ItemStack @NotNull [] getContents() {
     return new ItemStack[getSize()];
   }
 
@@ -72,7 +72,7 @@ public class OpenDummyInventory extends CraftInventory implements ViewOnly {
   }
 
   @Override
-  public @NotNull ItemStack[] getStorageContents() {
+  public @NotNull ItemStack @NotNull [] getStorageContents() {
     return new ItemStack[getSize()];
   }
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/bukkit/OpenDummyPlayerInventory.java

@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R2.container.bukkit;
+package com.lishid.openinv.internal.common.container.bukkit;
 
 import net.minecraft.world.Container;
 import org.bukkit.Material;
@@ -22,12 +22,12 @@ public class OpenDummyPlayerInventory extends OpenDummyInventory implements Play
   }
 
   @Override
-  public @NotNull ItemStack[] getArmorContents() {
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
     return new ItemStack[4];
   }
 
   @Override
-  public @NotNull ItemStack[] getExtraContents() {
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
     return new ItemStack[4];
   }
 
@@ -57,17 +57,17 @@ public class OpenDummyPlayerInventory extends OpenDummyInventory implements Play
   }
 
   @Override
-  public @Nullable ItemStack getItem(@NotNull EquipmentSlot slot) {
-    return null;
+  public @NotNull ItemStack getItem(@NotNull EquipmentSlot slot) {
+    return new ItemStack(Material.AIR);
   }
 
   @Override
-  public void setArmorContents(@Nullable ItemStack[] items) {
+  public void setArmorContents(ItemStack @NotNull [] items) {
 
   }
 
   @Override
-  public void setExtraContents(@Nullable ItemStack[] items) {
+  public void setExtraContents(ItemStack @NotNull [] items) {
 
   }
 
@@ -111,11 +111,13 @@ public class OpenDummyPlayerInventory extends OpenDummyInventory implements Play
 
   }
 
+  @Deprecated
   @Override
   public @NotNull ItemStack getItemInHand() {
     return new ItemStack(Material.AIR);
   }
 
+  @Deprecated
   @Override
   public void setItemInHand(@Nullable ItemStack stack) {
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/bukkit/OpenPlayerInventory.java

@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R3.container.bukkit;
+package com.lishid.openinv.internal.common.container.bukkit;
 
 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R3.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.OpenInventory;
 import net.minecraft.core.NonNullList;
 import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.entity.player.Inventory;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftInventory;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.entity.Player;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
@@ -14,6 +14,8 @@ import org.bukkit.inventory.PlayerInventory;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.List;
+
 public class OpenPlayerInventory extends CraftInventory implements PlayerInventory {
 
   public OpenPlayerInventory(@NotNull OpenInventory inventory) {
@@ -26,7 +28,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public ItemStack[] getContents() {
+  public ItemStack @NotNull [] getContents() {
     return asCraftMirror(getInventory().getOwnerHandle().getInventory().getContents());
   }
 
@@ -46,13 +48,13 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public ItemStack[] getStorageContents() {
-    return asCraftMirror(getInventory().getOwnerHandle().getInventory().items);
+  public ItemStack @NotNull [] getStorageContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getNonEquipmentItems());
   }
 
   @Override
   public void setStorageContents(ItemStack[] items) throws IllegalArgumentException {
-    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().items;
+    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().getNonEquipmentItems();
     int size = list.size();
     Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
     for (int index = 0; index < items.length; ++index) {
@@ -71,110 +73,113 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @NotNull ItemStack[] getArmorContents() {
-    return asCraftMirror(getInventory().getOwnerHandle().getInventory().armor);
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getArmorContents());
   }
 
   @Override
-  public void setArmorContents(@Nullable ItemStack[] items) {
-    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().armor;
-    int size = list.size();
+  public void setArmorContents(ItemStack @NotNull [] items) {
+    int size = Inventory.EQUIPMENT_SLOTS_SORTED_BY_INDEX.length;
     Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
     for (int index = 0; index < items.length; ++index) {
-      list.set(index, CraftItemStack.asNMSCopy(items[index]));
+      getInventory().getOwnerHandle().getInventory().equipment.set(
+          Inventory.EQUIPMENT_SLOTS_SORTED_BY_INDEX[index],
+          CraftItemStack.asNMSCopy(items[index]));
     }
   }
 
   @Override
-  public @NotNull ItemStack[] getExtraContents() {
-    return asCraftMirror(getInventory().getOwnerHandle().getInventory().offhand);
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
+    return asCraftMirror(List.of(getInventory().getOwnerHandle().getInventory().equipment.get(EquipmentSlot.OFFHAND)));
   }
 
   @Override
-  public void setExtraContents(@Nullable ItemStack[] items) {
-    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().offhand;
-    int size = list.size();
-    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
-    for (int index = 0; index < items.length; ++index) {
-      list.set(index, CraftItemStack.asNMSCopy(items[index]));
+  public void setExtraContents(ItemStack @NotNull [] items) {
+    Preconditions.checkArgument(items.length <= 1, "items.length must be <= 1");
+    for (ItemStack item : items) {
+      getInventory().getOwnerHandle().getInventory().equipment.set(EquipmentSlot.OFFHAND, CraftItemStack.asNMSCopy(item));
     }
   }
 
   @Override
-  public @Nullable ItemStack getHelmet() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.HEAD.getIndex()));
+  public @NotNull ItemStack getHelmet() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.HEAD));
   }
 
   @Override
   public void setHelmet(@Nullable ItemStack helmet) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.HEAD.getIndex(), CraftItemStack.asNMSCopy(helmet));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.HEAD, CraftItemStack.asNMSCopy(helmet));
   }
 
   @Override
-  public @Nullable ItemStack getChestplate() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.HEAD.getIndex()));
+  public @NotNull ItemStack getChestplate() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.CHEST));
   }
 
   @Override
   public void setChestplate(@Nullable ItemStack chestplate) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.CHEST.getIndex(), CraftItemStack.asNMSCopy(chestplate));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.CHEST, CraftItemStack.asNMSCopy(chestplate));
   }
 
   @Override
-  public @Nullable ItemStack getLeggings() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.LEGS.getIndex()));
+  public @NotNull ItemStack getLeggings() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.LEGS));
   }
 
   @Override
   public void setLeggings(@Nullable ItemStack leggings) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.LEGS.getIndex(), CraftItemStack.asNMSCopy(leggings));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.LEGS, CraftItemStack.asNMSCopy(leggings));
   }
 
   @Override
-  public @Nullable ItemStack getBoots() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.FEET.getIndex()));
+  public @NotNull ItemStack getBoots() {
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.FEET));
   }
 
   @Override
   public void setBoots(@Nullable ItemStack boots) {
-    getInventory().getOwnerHandle().getInventory().armor
-        .set(EquipmentSlot.FEET.getIndex(), CraftItemStack.asNMSCopy(boots));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.FEET, CraftItemStack.asNMSCopy(boots));
   }
 
   @Override
   public @NotNull ItemStack getItemInMainHand() {
     Inventory internal = getInventory().getOwnerHandle().getInventory();
-    return CraftItemStack.asCraftMirror(internal.getItem(internal.selected));
+    return CraftItemStack.asCraftMirror(internal.getSelectedItem());
   }
 
   @Override
   public void setItemInMainHand(@Nullable ItemStack item) {
     Inventory internal = getInventory().getOwnerHandle().getInventory();
-    internal.setItem(internal.selected, CraftItemStack.asNMSCopy(item));
+    internal.setSelectedItem(CraftItemStack.asNMSCopy(item));
   }
 
   @Override
   public @NotNull ItemStack getItemInOffHand() {
-    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().offhand.getFirst());
+    return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory().equipment
+        .get(EquipmentSlot.OFFHAND));
   }
 
   @Override
   public void setItemInOffHand(@Nullable ItemStack item) {
-    getInventory().getOwnerHandle().getInventory().offhand.set(0, CraftItemStack.asNMSCopy(item));
+    getInventory().getOwnerHandle().getInventory().equipment
+        .set(EquipmentSlot.OFFHAND, CraftItemStack.asNMSCopy(item));
   }
 
+  @Deprecated
   @Override
   public @NotNull ItemStack getItemInHand() {
     return getItemInMainHand();
   }
 
+  @Deprecated
   @Override
   public void setItemInHand(@Nullable ItemStack stack) {
     setItemInMainHand(stack);
@@ -183,17 +188,17 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   @Override
   public int getHeldItemSlot() {
     Inventory internal = getInventory().getOwnerHandle().getInventory();
-    return internal.items.size() - 9 + internal.selected;
+    return internal.getNonEquipmentItems().size() - 9 + internal.getSelectedSlot();
   }
 
   @Override
   public void setHeldItemSlot(int slot) {
     slot %= 9;
-    getInventory().getOwnerHandle().getInventory().selected = slot;
+    getInventory().getOwnerHandle().getInventory().setSelectedSlot(slot);
   }
 
   @Override
-  public @Nullable ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
+  public @NotNull ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
     return switch (slot) {
       case HAND -> getItemInMainHand();
       case OFF_HAND -> getItemInOffHand();

internal/common/src/main/java/com/lishid/openinv/internal/common/container/bukkit/OpenPlayerInventorySelf.java

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.bukkit;
+package com.lishid.openinv.internal.common.container.bukkit;
 
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.OpenInventory;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/menu/OpenChestMenu.java

@@ -1,13 +1,14 @@
-package com.lishid.openinv.internal.v1_21_R2.container.menu;
+package com.lishid.openinv.internal.common.container.menu;
 
 import com.google.common.base.Suppliers;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenDummyInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotPlaceholder;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyInventory;
+import com.lishid.openinv.internal.common.container.slot.SlotPlaceholder;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
 import it.unimi.dsi.fastutil.ints.IntArrayList;
 import it.unimi.dsi.fastutil.ints.IntList;
+import net.minecraft.network.HashedStack;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.player.Player;
@@ -19,9 +20,10 @@ import net.minecraft.world.inventory.ContainerListener;
 import net.minecraft.world.inventory.ContainerSynchronizer;
 import net.minecraft.world.inventory.DataSlot;
 import net.minecraft.world.inventory.MenuType;
+import net.minecraft.world.inventory.RemoteSlot;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -47,12 +49,12 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   protected final int topSize;
   private CraftInventoryView<OpenChestMenu<T>, Inventory> bukkitEntity;
   // Syncher fields
-  private @Nullable ContainerSynchronizer synchronizer;
-  private final List<DataSlot> dataSlots = new ArrayList<>();
-  private final IntList remoteDataSlots = new IntArrayList();
-  private final List<ContainerListener> containerListeners = new ArrayList<>();
-  private ItemStack remoteCarried = ItemStack.EMPTY;
-  private boolean suppressRemoteUpdates;
+  protected @Nullable ContainerSynchronizer synchronizer;
+  protected final List<DataSlot> dataSlots = new ArrayList<>();
+  protected final IntList remoteDataSlots = new IntArrayList();
+  protected final List<ContainerListener> containerListeners = new ArrayList<>();
+  private RemoteSlot remoteCarried = RemoteSlot.PLACEHOLDER;
+  protected boolean suppressRemoteUpdates;
 
   protected OpenChestMenu(
       @NotNull MenuType<ChestMenu> type,
@@ -124,10 +126,11 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   protected void preSlotSetup() {}
 
   protected @NotNull Slot getUpperSlot(int index, int x, int y) {
+    Slot slot = new Slot(container, index, x, y);
     if (viewOnly) {
-      return new SlotViewOnly(container, index, x, y);
+      return SlotViewOnly.wrap(slot);
     }
-    return new Slot(container, index, x, y);
+    return slot;
   }
 
 
@@ -176,9 +179,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
 
   private int getTopSize(ServerPlayer viewer) {
     MenuType<?> menuType = getType();
-    if (menuType == null) {
-      throw new IllegalStateException("MenuType cannot be null!");
-    } else if (menuType == MenuType.GENERIC_9x1) {
+    if (menuType == MenuType.GENERIC_9x1) {
       return 9;
     } else if (menuType == MenuType.GENERIC_9x2) {
       return 18;
@@ -284,7 +285,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public void clicked(int i, int j, ClickType clickType, Player player) {
+  public void clicked(int i, int j, @NotNull ClickType clickType, @NotNull Player player) {
     if (viewOnly) {
       if (clickType == ClickType.QUICK_CRAFT) {
         sendAllDataToRemote();
@@ -295,22 +296,22 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
     return true;
   }
 
   // Overrides from here on are purely to modify the sync process to send placeholder items.
   @Override
-  protected Slot addSlot(Slot slot) {
+  protected @NotNull Slot addSlot(@NotNull Slot slot) {
     slot.index = this.slots.size();
     this.slots.add(slot);
     this.lastSlots.add(ItemStack.EMPTY);
-    this.remoteSlots.add(ItemStack.EMPTY);
+    this.remoteSlots.add(this.synchronizer != null ? this.synchronizer.createSlot() : RemoteSlot.PLACEHOLDER);
     return slot;
   }
 
   @Override
-  protected DataSlot addDataSlot(DataSlot dataSlot) {
+  protected @NotNull DataSlot addDataSlot(@NotNull DataSlot dataSlot) {
     this.dataSlots.add(dataSlot);
     this.remoteDataSlots.add(0);
     return dataSlot;
@@ -324,7 +325,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public void addSlotListener(ContainerListener containerListener) {
+  public void addSlotListener(@NotNull ContainerListener containerListener) {
     if (!this.containerListeners.contains(containerListener)) {
       this.containerListeners.add(containerListener);
       this.broadcastChanges();
@@ -332,39 +333,45 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public void setSynchronizer(ContainerSynchronizer containerSynchronizer) {
+  public void setSynchronizer(@NotNull ContainerSynchronizer containerSynchronizer) {
     this.synchronizer = containerSynchronizer;
+    this.remoteCarried = synchronizer.createSlot();
+    this.remoteSlots.replaceAll(slot -> synchronizer.createSlot());
     this.sendAllDataToRemote();
   }
 
   @Override
   public void sendAllDataToRemote() {
+    List<ItemStack> contentsCopy = new ArrayList<>();
     for (int index = 0; index < slots.size(); ++index) {
       Slot slot = slots.get(index);
-      this.remoteSlots.set(index, (slot instanceof SlotPlaceholder placeholder ? placeholder.getOrDefault() : slot.getItem()).copy());
+      ItemStack itemStack = slot instanceof SlotPlaceholder placeholder ? placeholder.getOrDefault() : slot.getItem();
+      contentsCopy.add(itemStack);
+      this.remoteSlots.get(index).force(itemStack);
     }
 
-    remoteCarried = getCarried().copy();
+    remoteCarried.force(getCarried());
 
     for (int index = 0; index < this.dataSlots.size(); ++index) {
       this.remoteDataSlots.set(index, this.dataSlots.get(index).get());
     }
 
     if (this.synchronizer != null) {
-      this.synchronizer.sendInitialData(this, this.remoteSlots, this.remoteCarried, this.remoteDataSlots.toIntArray());
+      this.synchronizer.sendInitialData(this, contentsCopy, this.getCarried().copy(), this.remoteDataSlots.toIntArray());
     }
   }
 
   @Override
   public void broadcastCarriedItem() {
-    this.remoteCarried = this.getCarried().copy();
+    ItemStack carried = this.getCarried();
+    this.remoteCarried.force(carried);
     if (this.synchronizer != null) {
-      this.synchronizer.sendCarriedChange(this, this.remoteCarried);
+      this.synchronizer.sendCarriedChange(this, carried.copy());
     }
   }
 
   @Override
-  public void removeSlotListener(ContainerListener containerListener) {
+  public void removeSlotListener(@NotNull ContainerListener containerListener) {
     this.containerListeners.remove(containerListener);
   }
 
@@ -428,12 +435,11 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
 
   private void synchronizeSlotToRemote(int i, ItemStack itemStack, Supplier<ItemStack> supplier) {
     if (!this.suppressRemoteUpdates) {
-      ItemStack itemStack1 = this.remoteSlots.get(i);
-      if (!ItemStack.matches(itemStack1, itemStack)) {
-        ItemStack itemstack2 = supplier.get();
-        this.remoteSlots.set(i, itemstack2);
+      RemoteSlot slot = this.remoteSlots.get(i);
+      if (!slot.matches(itemStack)) {
+        slot.force(itemStack);
         if (this.synchronizer != null) {
-          this.synchronizer.sendSlotChange(this, i, itemstack2);
+          this.synchronizer.sendSlotChange(this, i, supplier.get());
         }
       }
     }
@@ -452,17 +458,20 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   private void synchronizeCarriedToRemote() {
-    if (!this.suppressRemoteUpdates && !ItemStack.matches(this.getCarried(), this.remoteCarried)) {
-      this.remoteCarried = this.getCarried().copy();
-      if (this.synchronizer != null) {
-        this.synchronizer.sendCarriedChange(this, this.remoteCarried);
+    if (!this.suppressRemoteUpdates) {
+      ItemStack carried = this.getCarried();
+      if (!this.remoteCarried.matches(carried)) {
+        this.remoteCarried.force(carried);
+        if (this.synchronizer != null) {
+          this.synchronizer.sendCarriedChange(this, carried.copy());
+        }
       }
     }
   }
 
   @Override
-  public void setRemoteCarried(ItemStack itemstack) {
-    this.remoteCarried = itemstack.copy();
+  public void setRemoteCarried(@NotNull HashedStack stack) {
+    this.remoteCarried.receive(stack);
   }
 
   @Override

internal/common/src/main/java/com/lishid/openinv/internal/common/container/menu/OpenEnderChestMenu.java

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R3.container.menu;
+package com.lishid.openinv.internal.common.container.menu;
 
-import com.lishid.openinv.internal.v1_21_R3.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.Slot;
@@ -18,7 +18,7 @@ public class OpenEnderChestMenu extends OpenChestMenu<OpenEnderChest> {
   }
 
   @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
     if (viewOnly) {
       return ItemStack.EMPTY;
     }

internal/common/src/main/java/com/lishid/openinv/internal/common/container/menu/OpenInventoryMenu.java

@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R3.container.menu;
+package com.lishid.openinv.internal.common.container.menu;
 
 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R3.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R3.container.bukkit.OpenDummyPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R3.container.bukkit.OpenPlayerInventorySelf;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyPlayerInventory;
+import com.lishid.openinv.internal.common.container.bukkit.OpenPlayerInventorySelf;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.ContentEquipment;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
 import com.lishid.openinv.util.Permissions;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.EquipmentSlot;
@@ -15,8 +15,8 @@ import net.minecraft.world.inventory.ChestMenu;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftInventoryView;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -35,7 +35,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
     int size = inventory.getContainerSize();
     // Disallow duplicate access to own main inventory contents.
     if (inventory.getOwnerHandle().equals(viewer)) {
-      size -= viewer.getInventory().items.size();
+      size -= viewer.getInventory().getNonEquipmentItems().size();
       size = ((int) Math.ceil(size / 9.0)) * 9;
     }
 
@@ -44,7 +44,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
 
   @Override
   protected void preSlotSetup() {
-    offset = ownContainer ? viewer.getInventory().items.size() : 0;
+    offset = ownContainer ? viewer.getInventory().getNonEquipmentItems().size() : 0;
   }
 
   @Override
@@ -195,7 +195,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
   }
 
   @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
     if (viewOnly) {
       return ItemStack.EMPTY;
     }
@@ -221,7 +221,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
         // If this is gear, try to move it to the correct slot first.
         case OFFHAND, FEET, LEGS, CHEST, HEAD -> {
           // Locate the correct slot in the contents following the main inventory.
-          for (int extra = container.getOwnerHandle().getInventory().items.size() - offset; extra < topSize; ++extra) {
+          for (int extra = container.getOwnerHandle().getInventory().getNonEquipmentItems().size() - offset; extra < topSize; ++extra) {
             Slot extraSlot = getSlot(extra);
             if (extraSlot instanceof ContentEquipment.SlotEquipment equipSlot
                 && equipSlot.getEquipmentSlot() == equipmentSlot) {
@@ -244,7 +244,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
         }
       } else {
         // If we didn't move to a gear slot, try to move to a main inventory slot.
-        if (!movedGear && !this.moveItemStackTo(itemStack, 0, container.getOwnerHandle().getInventory().items.size(), true)) {
+        if (!movedGear && !this.moveItemStackTo(itemStack, 0, container.getOwnerHandle().getInventory().getNonEquipmentItems().size(), true)) {
           return ItemStack.EMPTY;
         }
       }

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/Content.java

@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentCrafting.java

@@ -1,6 +1,7 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.OpenPlayer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.ContainerHelper;
@@ -30,11 +31,11 @@ public class ContentCrafting implements Content {
     return isAvailable(holder);
   }
 
-  static boolean isAvailable(@NotNull ServerPlayer holder) {
+  public static boolean isAvailable(@NotNull ServerPlayer holder) {
     // Player must be online and not in creative - since the creative client is (semi-)authoritative,
     // it ignores changes without extra help, and will delete the item as a result.
     // Spectator mode is technically possible but may cause the item to be dropped if the client opens an inventory.
-    return holder.connection != null && !holder.connection.isDisconnected() && holder.gameMode.isSurvival();
+    return OpenPlayer.isConnected(holder.connection) && holder.gameMode.isSurvival();
   }
 
   @Override
@@ -107,12 +108,12 @@ public class ContentCrafting implements Content {
     }
 
     @Override
-    public boolean mayPickup(Player player) {
+    public boolean mayPickup(@NotNull Player player) {
       return isAvailable();
     }
 
     @Override
-    public boolean mayPlace(ItemStack itemStack) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
       return isAvailable();
     }
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentCraftingResult.java

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.InventoryMenu;

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentCursor.java

@@ -1,6 +1,7 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.OpenPlayer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.player.Player;
@@ -63,7 +64,7 @@ public class ContentCursor implements Content {
     // Player must be online and not in creative - since the creative client is (semi-)authoritative,
     // it ignores changes without extra help, and will delete the item as a result.
     // Spectator mode is technically possible but may cause the item to be dropped if the client opens an inventory.
-    return holder.connection != null && !holder.connection.isDisconnected() && holder.gameMode.isSurvival();
+    return OpenPlayer.isConnected(holder.connection) && holder.gameMode.isSurvival();
   }
 
   @Override
@@ -93,12 +94,12 @@ public class ContentCursor implements Content {
     }
 
     @Override
-    public boolean mayPickup(Player player) {
+    public boolean mayPickup(@NotNull Player player) {
       return isAvailable();
     }
 
     @Override
-    public boolean mayPlace(ItemStack itemStack) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
       return isAvailable();
     }
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentDrop.java

@@ -1,6 +1,7 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.common.player.OpenPlayer;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.Slot;
@@ -63,14 +64,14 @@ public class ContentDrop implements Content {
 
     @Override
     public ItemStack getOrDefault() {
-      return holder.connection != null && !holder.connection.isDisconnected()
+      return OpenPlayer.isConnected(holder.connection)
           ? Placeholders.drop
           : Placeholders.blockedOffline;
     }
 
     @Override
-    public boolean mayPlace(ItemStack itemStack) {
-      return holder.connection != null && !holder.connection.isDisconnected();
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
+      return OpenPlayer.isConnected(holder.connection);
     }
 
     @Override

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentEquipment.java

@@ -1,8 +1,10 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
+import net.minecraft.world.ContainerHelper;
+import net.minecraft.world.entity.EntityEquipment;
 import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
@@ -12,13 +14,14 @@ import org.jetbrains.annotations.NotNull;
 /**
  * A slot for equipment that displays placeholders if empty.
  */
-public class ContentEquipment extends ContentList {
+public class ContentEquipment implements Content {
 
+  private EntityEquipment equipment;
   private final ItemStack placeholder;
   private final EquipmentSlot equipmentSlot;
 
-  public ContentEquipment(ServerPlayer holder, int index, EquipmentSlot equipmentSlot) {
-    super(holder, index, InventoryType.SlotType.ARMOR);
+  public ContentEquipment(ServerPlayer holder, EquipmentSlot equipmentSlot) {
+    setHolder(holder);
     placeholder = switch (equipmentSlot) {
       case HEAD -> Placeholders.emptyHelmet;
       case CHEST -> Placeholders.emptyChestplate;
@@ -31,7 +34,31 @@ public class ContentEquipment extends ContentList {
 
   @Override
   public void setHolder(@NotNull ServerPlayer holder) {
-    this.items = holder.getInventory().armor;
+    this.equipment = holder.getInventory().equipment;
+  }
+
+  @Override
+  public ItemStack get() {
+    return equipment.get(equipmentSlot);
+  }
+
+  @Override
+  public ItemStack remove() {
+    return equipment.set(equipmentSlot, ItemStack.EMPTY);
+  }
+
+  @Override
+  public ItemStack removePartial(int amount) {
+    ItemStack current = get();
+    if (!current.isEmpty() && amount > 0) {
+      return current.split(amount);
+    }
+    return ItemStack.EMPTY;
+  }
+
+  @Override
+  public void set(ItemStack itemStack) {
+    equipment.set(equipmentSlot, itemStack);
   }
 
   @Override
@@ -39,6 +66,11 @@ public class ContentEquipment extends ContentList {
     return new SlotEquipment(container, slot, x, y);
   }
 
+  @Override
+  public InventoryType.SlotType getSlotType() {
+    return InventoryType.SlotType.ARMOR;
+  }
+
   public class SlotEquipment extends SlotPlaceholder {
 
     private ServerPlayer viewer;
@@ -65,12 +97,12 @@ public class ContentEquipment extends ContentList {
     }
 
     @Override
-    public boolean mayPlace(ItemStack var0) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
       if (viewer == null) {
         return true;
       }
 
-      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(var0) == equipmentSlot;
+      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(itemStack) == equipmentSlot;
     }
 
   }

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentList.java

@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R3.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentOffHand.java

@@ -1,8 +1,11 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
+import com.lishid.openinv.internal.common.player.OpenPlayer;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.InventoryMenu;
 import net.minecraft.world.inventory.Slot;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
@@ -14,13 +17,13 @@ public class ContentOffHand extends ContentEquipment {
 
   private ServerPlayer holder;
 
-  public ContentOffHand(ServerPlayer holder, int localIndex) {
-    super(holder, localIndex, EquipmentSlot.OFFHAND);
+  public ContentOffHand(ServerPlayer holder) {
+    super(holder, EquipmentSlot.OFFHAND);
   }
 
   @Override
   public void setHolder(@NotNull ServerPlayer holder) {
-    this.items = holder.getInventory().offhand;
+    super.setHolder(holder);
     this.holder = holder;
   }
 
@@ -34,10 +37,13 @@ public class ContentOffHand extends ContentEquipment {
     return new SlotEquipment(container, slot, x, y) {
       @Override
       public void setChanged() {
-        if (holder.connection != null
-            && !holder.connection.isDisconnected()
-            && holder.containerMenu != holder.inventoryMenu) {
-          holder.resendItemInHands();
+        if (OpenPlayer.isConnected(holder.connection) && holder.containerMenu != holder.inventoryMenu) {
+          holder.connection.send(
+              new ClientboundContainerSetSlotPacket(
+                  holder.inventoryMenu.containerId,
+                  holder.inventoryMenu.incrementStateId(),
+                  InventoryMenu.SHIELD_SLOT,
+                  holder.getOffhandItem()));
         }
       }
     };

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/ContentViewOnly.java

@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
@@ -12,7 +12,7 @@ import org.jetbrains.annotations.NotNull;
  */
 public class ContentViewOnly implements Content {
 
-  @NotNull ServerPlayer holder;
+  protected @NotNull ServerPlayer holder;
 
   public ContentViewOnly(@NotNull ServerPlayer holder) {
     this.holder = holder;

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/SlotPlaceholder.java

@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.Slot;

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/SlotViewOnly.java

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
+package com.lishid.openinv.internal.common.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.Slot;
@@ -45,20 +45,20 @@ public class SlotViewOnly extends SlotPlaceholder {
   }
 
   @Override
-  public void onQuickCraft(ItemStack var0, ItemStack var1) {
+  public void onQuickCraft(@NotNull ItemStack itemStack1, @NotNull ItemStack itemStack2) {
   }
 
   @Override
-  public void onTake(Player var0, ItemStack var1) {
+  public void onTake(@NotNull Player player, @NotNull ItemStack itemStack) {
   }
 
   @Override
-  public boolean mayPlace(ItemStack var0) {
+  public boolean mayPlace(@NotNull ItemStack itemStack) {
     return false;
   }
 
   @Override
-  public ItemStack getItem() {
+  public @NotNull ItemStack getItem() {
     return ItemStack.EMPTY;
   }
 
@@ -68,15 +68,15 @@ public class SlotViewOnly extends SlotPlaceholder {
   }
 
   @Override
-  public void setByPlayer(ItemStack newStack) {
+  public void setByPlayer(@NotNull ItemStack newStack) {
   }
 
   @Override
-  public void setByPlayer(ItemStack newStack, ItemStack oldStack) {
+  public void setByPlayer(@NotNull ItemStack newStack, @NotNull ItemStack oldStack) {
   }
 
   @Override
-  public void set(ItemStack var0) {
+  public void set(@NotNull ItemStack itemStack) {
   }
 
   @Override
@@ -89,17 +89,17 @@ public class SlotViewOnly extends SlotPlaceholder {
   }
 
   @Override
-  public int getMaxStackSize(ItemStack itemStack) {
+  public int getMaxStackSize(@NotNull ItemStack itemStack) {
     return 0;
   }
 
   @Override
-  public ItemStack remove(int amount) {
+  public @NotNull ItemStack remove(int amount) {
     return ItemStack.EMPTY;
   }
 
   @Override
-  public boolean mayPickup(Player var0) {
+  public boolean mayPickup(@NotNull Player player) {
     return false;
   }
 
@@ -109,27 +109,27 @@ public class SlotViewOnly extends SlotPlaceholder {
   }
 
   @Override
-  public Optional<ItemStack> tryRemove(int var0, int var1, Player var2) {
+  public @NotNull Optional<ItemStack> tryRemove(int var0, int var1, @NotNull Player player) {
     return Optional.empty();
   }
 
   @Override
-  public ItemStack safeTake(int var0, int var1, Player var2) {
+  public @NotNull ItemStack safeTake(int var0, int var1, @NotNull Player player) {
     return ItemStack.EMPTY;
   }
 
   @Override
-  public ItemStack safeInsert(ItemStack itemStack) {
+  public @NotNull ItemStack safeInsert(@NotNull ItemStack itemStack) {
     return itemStack;
   }
 
   @Override
-  public ItemStack safeInsert(ItemStack itemStack, int amount) {
+  public @NotNull ItemStack safeInsert(@NotNull ItemStack itemStack, int amount) {
     return itemStack;
   }
 
   @Override
-  public boolean allowModification(Player var0) {
+  public boolean allowModification(@NotNull Player player) {
     return false;
   }
 

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/placeholder/PlaceholderLoader.java

@@ -0,0 +1,40 @@
+package com.lishid.openinv.internal.common.container.slot.placeholder;
+
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.TagParser;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.CustomModelData;
+import net.minecraft.world.item.component.DyedItemColor;
+import net.minecraft.world.item.component.TooltipDisplay;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+
+public class PlaceholderLoader extends PlaceholderLoaderBase {
+
+  private static final CustomModelData DEFAULT_CUSTOM_MODEL_DATA = new CustomModelData(List.of(), List.of(), List.of("openinv:custom"), List.of());
+  private static final TooltipDisplay HIDE_TOOLTIP = new TooltipDisplay(true, new LinkedHashSet<>());
+
+  @Override
+  protected @NotNull CompoundTag parseTag(@NotNull String itemText) throws Exception {
+    return TagParser.parseCompoundFully(itemText);
+  }
+
+  @Override
+  protected void addModelData(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+  }
+
+  @Override
+  protected void hideTooltip(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.TOOLTIP_DISPLAY, HIDE_TOOLTIP);
+  }
+
+  @Override
+  protected DyedItemColor getDye(int rgb) {
+    return new DyedItemColor(rgb);
+  }
+
+}

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/placeholder/PlaceholderLoaderBase.java

@@ -1,18 +1,14 @@
-package com.lishid.openinv.internal.v1_21_R2.container;
+package com.lishid.openinv.internal.common.container.slot.placeholder;
 
 import net.minecraft.core.Registry;
 import net.minecraft.core.RegistryAccess;
 import net.minecraft.core.component.DataComponents;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.TagParser;
 import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.util.Unit;
 import net.minecraft.world.item.DyeColor;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
-import net.minecraft.world.item.component.CustomModelData;
 import net.minecraft.world.item.component.DyedItemColor;
 import net.minecraft.world.level.GameType;
 import net.minecraft.world.level.ItemLike;
@@ -20,86 +16,87 @@ import net.minecraft.world.level.block.entity.BannerPattern;
 import net.minecraft.world.level.block.entity.BannerPatternLayers;
 import net.minecraft.world.level.block.entity.BannerPatterns;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R2.CraftRegistry;
+import org.bukkit.craftbukkit.CraftRegistry;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
-import java.util.EnumMap;
 import java.util.List;
 import java.util.Optional;
 
-public final class Placeholders {
+public abstract class PlaceholderLoaderBase {
 
-  private static final CustomModelData DEFAULT_CUSTOM_MODEL_DATA = new CustomModelData(9999);
-  public static final @NotNull EnumMap<GameType, ItemStack> BLOCKED_GAME_TYPE = new EnumMap<>(GameType.class);
-  public static @NotNull ItemStack craftingOutput = defaultCraftingOutput();
-  public static @NotNull ItemStack cursor = defaultCursor();
-  public static @NotNull ItemStack drop = defaultDrop();
-  public static @NotNull ItemStack emptyHelmet = getEmptyArmor(Items.LEATHER_HELMET);
-  public static @NotNull ItemStack emptyChestplate = getEmptyArmor(Items.LEATHER_CHESTPLATE);
-  public static @NotNull ItemStack emptyLeggings = getEmptyArmor(Items.LEATHER_LEGGINGS);
-  public static @NotNull ItemStack emptyBoots = getEmptyArmor(Items.LEATHER_BOOTS);
-  public static @NotNull ItemStack emptyOffHand = getEmptyShield();
-  public static @NotNull ItemStack notSlot = defaultNotSlot();
-  public static @NotNull ItemStack blockedOffline = defaultBlockedOffline();
-
-  static {
+  protected PlaceholderLoaderBase() {
     for (GameType type : GameType.values()) {
       // Barrier: "Not available - Creative" etc.
       ItemStack typeItem = new ItemStack(Items.BARRIER);
       typeItem.set(
           DataComponents.ITEM_NAME,
           Component.translatable("options.narrator.notavailable").append(" - ").append(type.getShortDisplayName()));
-      BLOCKED_GAME_TYPE.put(type, typeItem);
+      Placeholders.BLOCKED_GAME_TYPE.put(type, typeItem);
     }
+    Placeholders.craftingOutput = defaultCraftingOutput();
+    Placeholders.cursor = defaultCursor();
+    Placeholders.drop = defaultDrop();
+    Placeholders.emptyHelmet = getEmptyArmor(Items.LEATHER_HELMET);
+    Placeholders.emptyChestplate = getEmptyArmor(Items.LEATHER_CHESTPLATE);
+    Placeholders.emptyLeggings = getEmptyArmor(Items.LEATHER_LEGGINGS);
+    Placeholders.emptyBoots = getEmptyArmor(Items.LEATHER_BOOTS);
+    Placeholders.emptyOffHand = defaultShield();
+    Placeholders.notSlot = defaultNotSlot();
+    Placeholders.blockedOffline = defaultBlockedOffline();
   }
 
-  public static void load(@NotNull ConfigurationSection section) throws Exception {
-    craftingOutput = parse(section, "crafting-output", craftingOutput);
-    cursor = parse(section, "cursor", cursor);
-    drop = parse(section, "drop", drop);
-    emptyHelmet = parse(section, "empty-helmet", emptyHelmet);
-    emptyChestplate = parse(section, "empty-chestplate", emptyChestplate);
-    emptyLeggings = parse(section, "empty-leggings", emptyLeggings);
-    emptyBoots = parse(section, "empty-boots", emptyBoots);
-    emptyOffHand = parse(section, "empty-off-hand", emptyOffHand);
-    notSlot = parse(section, "not-a-slot", notSlot);
-    blockedOffline = parse(section, "blocked.offline", blockedOffline);
-    BLOCKED_GAME_TYPE.put(GameType.CREATIVE, parse(section, "blocked.creative", BLOCKED_GAME_TYPE.get(GameType.CREATIVE)));
-    BLOCKED_GAME_TYPE.put(GameType.SPECTATOR, parse(section, "blocked.spectator", BLOCKED_GAME_TYPE.get(GameType.SPECTATOR)));
+  public void load(@Nullable ConfigurationSection section) throws Exception {
+    Placeholders.craftingOutput = parse(section, "crafting-output", Placeholders.craftingOutput);
+    Placeholders.cursor = parse(section, "cursor", Placeholders.cursor);
+    Placeholders.drop = parse(section, "drop", Placeholders.drop);
+    Placeholders.emptyHelmet = parse(section, "empty-helmet", Placeholders.emptyHelmet);
+    Placeholders.emptyChestplate = parse(section, "empty-chestplate", Placeholders.emptyChestplate);
+    Placeholders.emptyLeggings = parse(section, "empty-leggings", Placeholders.emptyLeggings);
+    Placeholders.emptyBoots = parse(section, "empty-boots", Placeholders.emptyBoots);
+    Placeholders.emptyOffHand = parse(section, "empty-off-hand", Placeholders.emptyOffHand);
+    Placeholders.notSlot = parse(section, "not-a-slot", Placeholders.notSlot);
+    Placeholders.blockedOffline = parse(section, "blocked.offline", Placeholders.blockedOffline);
+    Placeholders.BLOCKED_GAME_TYPE.put(GameType.CREATIVE, parse(section, "blocked.creative", Placeholders.BLOCKED_GAME_TYPE.get(GameType.CREATIVE)));
+    Placeholders.BLOCKED_GAME_TYPE.put(GameType.SPECTATOR, parse(section, "blocked.spectator", Placeholders.BLOCKED_GAME_TYPE.get(GameType.SPECTATOR)));
   }
 
-  private static @NotNull ItemStack parse(
-      @NotNull ConfigurationSection section,
+  private @NotNull ItemStack parse(
+      @Nullable ConfigurationSection section,
       @NotNull String path,
       @NotNull ItemStack defaultStack) throws Exception {
+    if (section == null) {
+      return defaultStack;
+    }
+
     String itemText = section.getString(path);
 
     if (itemText == null) {
       return defaultStack;
     }
 
-    CompoundTag compoundTag = TagParser.parseTag(itemText);
+    CompoundTag compoundTag = parseTag(itemText);
     Optional<ItemStack> parsed = ItemStack.parse(CraftRegistry.getMinecraftRegistry(), compoundTag);
     return parsed.filter(itemStack -> !itemStack.isEmpty()).orElse(defaultStack);
   }
 
-  public static ItemStack survivalOnly(@NotNull ServerPlayer serverPlayer) {
-    if (serverPlayer.connection == null || serverPlayer.connection.isDisconnected()) {
-      return blockedOffline;
-    }
+  protected abstract @NotNull CompoundTag parseTag(@NotNull String itemText) throws Exception;
 
-    return BLOCKED_GAME_TYPE.getOrDefault(serverPlayer.gameMode.getGameModeForPlayer(), ItemStack.EMPTY);
-  }
+  protected abstract void addModelData(@NotNull ItemStack itemStack);
 
-  private static ItemStack defaultCraftingOutput() {
+  protected abstract void hideTooltip(@NotNull ItemStack itemStack);
+
+  protected abstract DyedItemColor getDye(int rgb);
+
+  protected @NotNull ItemStack defaultCraftingOutput() {
     // Crafting table: "Crafting"
     ItemStack itemStack = new ItemStack(Items.CRAFTING_TABLE);
     itemStack.set(DataComponents.ITEM_NAME, Component.translatable("container.crafting"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    addModelData(itemStack);
     return itemStack;
   }
 
-  private static ItemStack defaultCursor() {
+  protected @NotNull ItemStack defaultCursor() {
     // Cursor-like banner with no tooltip
     ItemStack itemStack = new ItemStack(Items.WHITE_BANNER);
     RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
@@ -112,31 +109,32 @@ public final class Placeholders {
             new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfDiagBottomRight), DyeColor.GRAY),
             new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(downRight), DyeColor.WHITE),
             new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(border), DyeColor.GRAY))));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+    addModelData(itemStack);
+    hideTooltip(itemStack);
     return itemStack;
   }
 
-  private static ItemStack defaultDrop() {
+  protected @NotNull ItemStack defaultDrop() {
     // Dropper: "Drop Selected Item"
     ItemStack itemStack = new ItemStack(Items.DROPPER);
     // Note: translatable component, not keybind component! We want the text identifying the keybind, not the key.
     itemStack.set(DataComponents.ITEM_NAME, Component.translatable("key.drop"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    addModelData(itemStack);
     return itemStack;
   }
 
-  private static ItemStack getEmptyArmor(ItemLike item) {
+  protected @NotNull ItemStack getEmptyArmor(@NotNull ItemLike item) {
     // Inventory-background-grey-ish leather armor with no tooltip
     ItemStack itemStack = new ItemStack(item);
-    DyedItemColor color = new DyedItemColor(0xC8C8C8, false);
+    DyedItemColor color = getDye(0xC8C8C8);
     itemStack.set(DataComponents.DYED_COLOR, color);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    hideTooltip(itemStack);
+    addModelData(itemStack);
     return itemStack;
   }
 
-  private static ItemStack getEmptyShield() {
+  protected @NotNull ItemStack defaultShield() {
+    // Shield with "missing texture" pattern, magenta and black squares.
     ItemStack itemStack = new ItemStack(Items.SHIELD);
     itemStack.set(DataComponents.BASE_COLOR, DyeColor.MAGENTA);
     RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
@@ -153,20 +151,20 @@ public final class Placeholders {
             new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomLeft), DyeColor.MAGENTA),
             new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topRight), DyeColor.BLACK),
             new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomRight), DyeColor.BLACK))));
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    hideTooltip(itemStack);
+    addModelData(itemStack);
     return itemStack;
   }
 
-  private static ItemStack defaultNotSlot() {
+  protected @NotNull ItemStack defaultNotSlot() {
     // White pane with no tooltip
     ItemStack itemStack = new ItemStack(Items.WHITE_STAINED_GLASS_PANE);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
+    hideTooltip(itemStack);
+    addModelData(itemStack);
     return itemStack;
   }
 
-  private static ItemStack defaultBlockedOffline() {
+  protected @NotNull ItemStack defaultBlockedOffline() {
     // Barrier: "Not available - Offline"
     ItemStack itemStack = new ItemStack(Items.BARRIER);
     itemStack.set(DataComponents.ITEM_NAME,
@@ -176,8 +174,4 @@ public final class Placeholders {
     return itemStack;
   }
 
-  private Placeholders() {
-    throw new IllegalStateException("Cannot create instance of utility class.");
-  }
-
 }

internal/common/src/main/java/com/lishid/openinv/internal/common/container/slot/placeholder/Placeholders.java

@@ -0,0 +1,37 @@
+package com.lishid.openinv.internal.common.container.slot.placeholder;
+
+import com.lishid.openinv.internal.common.player.OpenPlayer;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.level.GameType;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.EnumMap;
+
+public final class Placeholders {
+
+  static final @NotNull EnumMap<GameType, ItemStack> BLOCKED_GAME_TYPE = new EnumMap<>(GameType.class);
+  public static @NotNull ItemStack craftingOutput = ItemStack.EMPTY;
+  public static @NotNull ItemStack cursor = ItemStack.EMPTY;
+  public static @NotNull ItemStack drop = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyHelmet = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyChestplate = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyLeggings = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyBoots = ItemStack.EMPTY;
+  public static @NotNull ItemStack emptyOffHand = ItemStack.EMPTY;
+  public static @NotNull ItemStack notSlot = ItemStack.EMPTY;
+  public static @NotNull ItemStack blockedOffline = ItemStack.EMPTY;
+
+  public static ItemStack survivalOnly(@NotNull ServerPlayer serverPlayer) {
+    if (!OpenPlayer.isConnected(serverPlayer.connection)) {
+      return blockedOffline;
+    }
+
+    return BLOCKED_GAME_TYPE.getOrDefault(serverPlayer.gameMode.getGameModeForPlayer(), ItemStack.EMPTY);
+  }
+
+  private Placeholders() {
+    throw new IllegalStateException("Cannot create instance of utility class.");
+  }
+
+}

internal/common/src/main/java/com/lishid/openinv/internal/common/player/OpenPlayer.java

@@ -1,4 +1,4 @@
-package com.lishid.openinv.internal.v1_21_R3.player;
+package com.lishid.openinv.internal.common.player;
 
 import com.lishid.openinv.event.OpenEvents;
 import com.mojang.logging.LogUtils;
@@ -8,12 +8,14 @@ import net.minecraft.nbt.NbtIo;
 import net.minecraft.nbt.NumericTag;
 import net.minecraft.nbt.Tag;
 import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.network.ServerGamePacketListenerImpl;
 import net.minecraft.world.level.storage.PlayerDataStorage;
-import org.bukkit.craftbukkit.v1_21_R3.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R3.entity.CraftPlayer;
+import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.craftbukkit.entity.CraftPlayer;
 import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.Unmodifiable;
 
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -29,7 +31,8 @@ public class OpenPlayer extends CraftPlayer {
    * @see net.minecraft.world.entity.player.Player#addAdditionalSaveData(CompoundTag)
    * @see net.minecraft.world.entity.LivingEntity#addAdditionalSaveData(CompoundTag)
    */
-  private static final Set<String> RESET_TAGS = Set.of(
+  @Unmodifiable
+  protected static final Set<String> RESET_TAGS = Set.of(
       // Entity#saveWithoutId(CompoundTag)
       "CustomName",
       "CustomNameVisible",
@@ -42,6 +45,7 @@ public class OpenPlayer extends CraftPlayer {
       "Passengers",
       // ServerPlayer#addAdditionalSaveData(CompoundTag)
       // Intentional omissions to prevent mount loss: Attach, Entity, and RootVehicle
+      // As of 1.21.5 only ender_pearls tag still needs to be reset. Rest are for backwards compatibility.
       "warden_spawn_tracker",
       "enteredNetherPosition",
       "SpawnX",
@@ -56,18 +60,23 @@ public class OpenPlayer extends CraftPlayer {
       "ShoulderEntityLeft",
       "ShoulderEntityRight",
       "LastDeathLocation",
-      "current_explosion_impact_pos",
+      "current_explosion_impact_pos", // Unnecessary in 1.21.5
       // LivingEntity#addAdditionalSaveData(CompoundTag)
       "active_effects",
       "SleepingX",
       "SleepingY",
       "SleepingZ",
-      "Brain"
+      "Brain",
+      "last_hurt_by_player",
+      "last_hurt_by_player_memory_time",
+      "last_hurt_by_mob",
+      "ticks_since_last_hurt_by_mob",
+      "equipment"
   );
 
   private final PlayerManager manager;
 
-  OpenPlayer(CraftServer server, ServerPlayer entity, PlayerManager manager) {
+  protected OpenPlayer(CraftServer server, ServerPlayer entity, PlayerManager manager) {
     super(server, entity);
     this.manager = manager;
   }
@@ -110,7 +119,7 @@ public class OpenPlayer extends CraftPlayer {
   }
 
   @Contract("null -> new")
-  private @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
+  protected @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
     if (oldData == null) {
       return new CompoundTag();
     }
@@ -119,8 +128,7 @@ public class OpenPlayer extends CraftPlayer {
     oldData = oldData.copy();
 
     // Remove vanilla/server data that is not written every time.
-    oldData.getAllKeys()
-        .removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit"));
+    oldData.keySet().removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit") || key.startsWith("Paper") && key.length() > 5);
 
     return oldData;
   }
@@ -175,4 +183,8 @@ public class OpenPlayer extends CraftPlayer {
     }
   }
 
+  public static boolean isConnected(@Nullable ServerGamePacketListenerImpl connection) {
+    return connection != null && !connection.isDisconnected();
+  }
+
 }

internal/common/src/main/java/com/lishid/openinv/internal/common/player/PlayerManager.java

@@ -1,10 +1,11 @@
-package com.lishid.openinv.internal.v1_21_R2.player;
+package com.lishid.openinv.internal.common.player;
 
 import com.lishid.openinv.internal.ISpecialInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenInventory;
 import com.mojang.authlib.GameProfile;
 import com.mojang.serialization.Dynamic;
+import io.papermc.paper.adventure.PaperAdventure;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.nbt.NbtOps;
 import net.minecraft.network.chat.Component;
@@ -23,34 +24,24 @@ import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.Server;
 import org.bukkit.World;
-import org.bukkit.craftbukkit.v1_21_R2.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R2.CraftWorld;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftPlayer;
-import org.bukkit.craftbukkit.v1_21_R2.event.CraftEventFactory;
+import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.craftbukkit.CraftWorld;
+import org.bukkit.craftbukkit.entity.CraftPlayer;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.InventoryView;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.lang.reflect.Field;
+import java.util.Optional;
 import java.util.UUID;
 import java.util.logging.Logger;
 
 public class PlayerManager implements com.lishid.openinv.internal.PlayerManager {
 
-  private static boolean paper;
-
-  static {
-    try {
-      Class.forName("io.papermc.paper.configuration.Configuration");
-      paper = true;
-    } catch (ClassNotFoundException ignored) {
-      paper = false;
-    }
-  }
-
-  private final @NotNull Logger logger;
-  private @Nullable Field bukkitEntity;
+  protected final @NotNull Logger logger;
+  protected @Nullable Field bukkitEntity;
 
   public PlayerManager(@NotNull Logger logger) {
     this.logger = logger;
@@ -107,7 +98,7 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
     return null;
   }
 
-  private @NotNull ServerPlayer createNewPlayer(
+  protected @NotNull ServerPlayer createNewPlayer(
       @NotNull MinecraftServer server,
       @NotNull ServerLevel worldServer,
       @NotNull final OfflinePlayer offline) {
@@ -158,40 +149,54 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
     // Game type settings are also loaded separately.
     player.loadGameTypes(loadedData);
 
-    if (paper) {
-      // Paper: world is not loaded by ServerPlayer#load(CompoundTag).
-      parseWorld(player, loadedData);
-    }
+    // World is not loaded by ServerPlayer#load(CompoundTag) on Paper.
+    parseWorld(player, loadedData);
 
     return true;
   }
 
-  private void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
+  protected void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
     // See PlayerList#placeNewPlayer
     World bukkitWorld;
-    if (loadedData.contains("WorldUUIDMost") && loadedData.contains("WorldUUIDLeast")) {
+    Optional<Long> msbs = loadedData.getLong("WorldUUIDMost");
+    Optional<Long> lsbs = loadedData.getLong("WorldUUIDLeast");
+    if (msbs.isPresent() && lsbs.isPresent()) {
       // Modern Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(new UUID(loadedData.getLong("WorldUUIDMost"), loadedData.getLong("WorldUUIDLeast")));
-    } else if (loadedData.contains("world", net.minecraft.nbt.Tag.TAG_STRING)) {
-      // Legacy Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(loadedData.getString("world"));
+      bukkitWorld = Bukkit.getServer().getWorld(new UUID(msbs.get(), lsbs.get()));
     } else {
-      // Vanilla player data.
-      DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
-          .resultOrPartial(logger::warning)
-          .map(player.server::getLevel)
-          // If ServerLevel exists, set, otherwise move to spawn.
-          .ifPresentOrElse(player::setServerLevel, () -> player.spawnIn(null));
-      return;
+      Optional<String> worldName = loadedData.getString("world");
+      if (worldName.isPresent()) {
+        // Legacy Bukkit world.
+        bukkitWorld = Bukkit.getServer().getWorld(worldName.get());
+      } else {
+        // Vanilla player data.
+        DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
+            .resultOrPartial(logger::warning)
+            .map(player.server::getLevel)
+            // If ServerLevel exists, set, otherwise move to spawn.
+            .ifPresentOrElse(player::setServerLevel, () -> spawnInDefaultWorld(player));
+        return;
+      }
     }
     if (bukkitWorld == null) {
-      player.spawnIn(null);
+      spawnInDefaultWorld(player);
       return;
     }
     player.setServerLevel(((CraftWorld) bukkitWorld).getHandle());
   }
 
-  private void injectPlayer(ServerPlayer player) throws IllegalAccessException {
+  protected void spawnInDefaultWorld(ServerPlayer player) {
+    ServerLevel level = player.server.getLevel(Level.OVERWORLD);
+    if (level != null) {
+      // Adjust player to default spawn (in keeping with Paper handling) when world not found.
+      player.snapTo(player.adjustSpawnLocation(level, level.getSharedSpawnPos()).getBottomCenter(), level.getSharedSpawnAngle(), 0.0F);
+      player.spawnIn(level);
+    } else {
+      logger.warning("Tried to load player with invalid world when no fallback was available!");
+    }
+  }
+
+  protected void injectPlayer(ServerPlayer player) throws IllegalAccessException {
     if (bukkitEntity == null) {
       return;
     }
@@ -223,7 +228,7 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
   public @Nullable InventoryView openInventory(@NotNull Player bukkitPlayer, @NotNull ISpecialInventory inventory, boolean viewOnly) {
     ServerPlayer player = getHandle(bukkitPlayer);
 
-    if (player.connection == null) {
+    if (!OpenPlayer.isConnected(player.connection)) {
       return null;
     }
 
@@ -250,15 +255,21 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
     // resulting in a title change but no other state modifications (like cursor position).
     menu.setTitle(title);
 
-    menu = CraftEventFactory.callInventoryOpenEvent(player, menu, false);
+    var pair = CraftEventFactory.callInventoryOpenEventWithTitle(player, menu);
+    menu = pair.getSecond();
 
     // Menu is null if event is cancelled.
     if (menu == null) {
       return null;
     }
 
+    var newTitle = pair.getFirst();
+    if (newTitle != null) {
+      title = PaperAdventure.asVanilla(newTitle);
+    }
+
     player.containerMenu = menu;
-    player.connection.send(new ClientboundOpenScreenPacket(menu.containerId, menu.getType(), menu.getTitle()));
+    player.connection.send(new ClientboundOpenScreenPacket(menu.containerId, menu.getType(), title));
     player.initMenu(menu);
 
     return menu.getBukkitView();

internal/paper1_21_1/build.gradle.kts

@@ -0,0 +1,28 @@
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+  implementation(project(":openinvadaptercommon"))
+  implementation(project(":openinvadapterpaper1_21_4"))
+  implementation(project(":openinvadapterpaper1_21_3"))
+
+  paperweight.paperDevBundle("1.21.1-R0.1-SNAPSHOT")
+}

internal/paper1_21_1/src/main/java/com/lishid/openinv/internal/paper1_21_1/InternalAccessor.java

@@ -0,0 +1,80 @@
+package com.lishid.openinv.internal.paper1_21_1;
+
+import com.lishid.openinv.internal.Accessor;
+import com.lishid.openinv.internal.IAnySilentContainer;
+import com.lishid.openinv.internal.ISpecialEnderChest;
+import com.lishid.openinv.internal.ISpecialInventory;
+import com.lishid.openinv.internal.ISpecialPlayerInventory;
+import com.lishid.openinv.internal.common.container.AnySilentContainer;
+import com.lishid.openinv.internal.paper1_21_1.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_1.container.slot.placeholder.PlaceholderLoader;
+import com.lishid.openinv.internal.paper1_21_1.player.PlayerManager;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenEnderChest;
+import com.lishid.openinv.util.lang.LanguageManager;
+import net.minecraft.world.Container;
+import org.bukkit.configuration.ConfigurationSection;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.Inventory;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class InternalAccessor implements Accessor {
+
+  private final @NotNull Logger logger;
+  private final @NotNull PlayerManager manager;
+  private final @NotNull AnySilentContainer anySilentContainer;
+
+  public InternalAccessor(@NotNull Logger logger, @NotNull LanguageManager lang) {
+    this.logger = logger;
+    this.manager = new PlayerManager(logger);
+    this.anySilentContainer = new AnySilentContainer(logger, lang);
+  }
+
+  @Override
+  public @NotNull PlayerManager getPlayerManager() {
+    return manager;
+  }
+
+  @Override
+  public @NotNull IAnySilentContainer getAnySilentContainer() {
+    return anySilentContainer;
+  }
+
+  @Override
+  public @NotNull ISpecialPlayerInventory createPlayerInventory(@NotNull Player player) {
+    return new OpenInventory(player);
+  }
+
+  @Override
+  public @NotNull ISpecialEnderChest createEnderChest(@NotNull Player player) {
+    return new OpenEnderChest(player);
+  }
+
+  @Override
+  public <T extends ISpecialInventory> @Nullable T get(@NotNull Inventory bukkitInventory, @NotNull Class<T> clazz) {
+    if (!(bukkitInventory instanceof CraftInventory craftInventory)) {
+      return null;
+    }
+    Container container = craftInventory.getInventory();
+    if (clazz.isInstance(container)) {
+      return clazz.cast(container);
+    }
+    return null;
+  }
+
+  @Override
+  public void reload(@NotNull ConfigurationSection config) {
+    ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new PlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
+    }
+  }
+
+}

internal/paper1_21_1/src/main/java/com/lishid/openinv/internal/paper1_21_1/container/OpenInventory.java

@@ -0,0 +1,20 @@
+package com.lishid.openinv.internal.paper1_21_1.container;
+
+import com.lishid.openinv.internal.common.container.slot.Content;
+import com.lishid.openinv.internal.paper1_21_1.container.slot.ContentCraftingResult;
+import net.minecraft.server.level.ServerPlayer;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+public class OpenInventory extends com.lishid.openinv.internal.paper1_21_4.container.OpenInventory {
+
+  public OpenInventory(@NotNull Player bukkitPlayer) {
+    super(bukkitPlayer);
+  }
+
+  @Override
+  protected Content getCraftingResult(@NotNull ServerPlayer serverPlayer) {
+    return new ContentCraftingResult(serverPlayer);
+  }
+
+}

internal/paper1_21_1/src/main/java/com/lishid/openinv/internal/paper1_21_1/container/slot/ContentCraftingResult.java

@@ -1,6 +1,9 @@
-package com.lishid.openinv.internal.v1_21_R3.container.slot;
+package com.lishid.openinv.internal.paper1_21_1.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R3.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.ContentCrafting;
+import com.lishid.openinv.internal.common.container.slot.ContentViewOnly;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.inventory.InventoryMenu;
@@ -9,11 +12,6 @@ import net.minecraft.world.item.ItemStack;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
 
-/**
- * A slot allowing viewing of the crafting result.
- *
- * <p>Unmodifiable because I said so. Use your own crafting grid.</p>
- */
 public class ContentCraftingResult extends ContentViewOnly {
 
   public ContentCraftingResult(@NotNull ServerPlayer holder) {
@@ -23,7 +21,7 @@ public class ContentCraftingResult extends ContentViewOnly {
   @Override
   public ItemStack get() {
     InventoryMenu inventoryMenu = holder.inventoryMenu;
-    return inventoryMenu.getResultSlot().getItem();
+    return inventoryMenu.getSlot(inventoryMenu.getResultSlotIndex()).getItem();
   }
 
   @Override
@@ -35,7 +33,7 @@ public class ContentCraftingResult extends ContentViewOnly {
           return Placeholders.survivalOnly(holder);
         }
         InventoryMenu inventoryMenu = holder.inventoryMenu;
-        return inventoryMenu.getResultSlot().getItem();
+        return inventoryMenu.getSlot(inventoryMenu.getResultSlotIndex()).getItem();
       }
     };
   }

internal/paper1_21_1/src/main/java/com/lishid/openinv/internal/paper1_21_1/container/slot/placeholder/PlaceholderLoader.java

@@ -0,0 +1,65 @@
+package com.lishid.openinv.internal.paper1_21_1.container.slot.placeholder;
+
+import com.lishid.openinv.internal.paper1_21_3.container.slot.placeholder.NumericDataPlaceholderLoader;
+import net.minecraft.core.Registry;
+import net.minecraft.core.RegistryAccess;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.util.Unit;
+import net.minecraft.world.item.DyeColor;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.block.entity.BannerPattern;
+import net.minecraft.world.level.block.entity.BannerPatternLayers;
+import net.minecraft.world.level.block.entity.BannerPatterns;
+import org.bukkit.craftbukkit.CraftRegistry;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.List;
+
+public class PlaceholderLoader extends NumericDataPlaceholderLoader {
+
+  @Override
+  protected @NotNull ItemStack defaultCursor() {
+    // Cursor-like banner with no tooltip
+    ItemStack itemStack = new ItemStack(Items.WHITE_BANNER);
+    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
+    Registry<BannerPattern> bannerPatterns = minecraftRegistry.registryOrThrow(Registries.BANNER_PATTERN);
+    BannerPattern halfDiagBottomRight = bannerPatterns.getOrThrow(BannerPatterns.DIAGONAL_RIGHT);
+    BannerPattern downRight = bannerPatterns.getOrThrow(BannerPatterns.STRIPE_DOWNRIGHT);
+    BannerPattern border = bannerPatterns.getOrThrow(BannerPatterns.BORDER);
+    itemStack.set(DataComponents.BANNER_PATTERNS,
+        new BannerPatternLayers(List.of(
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfDiagBottomRight), DyeColor.GRAY),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(downRight), DyeColor.WHITE),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(border), DyeColor.GRAY))));
+    addModelData(itemStack);
+    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+    return itemStack;
+  }
+
+  @Override
+  protected @NotNull ItemStack defaultShield() {
+    // Shield with "missing texture" pattern, magenta and black squares.
+    ItemStack itemStack = new ItemStack(Items.SHIELD);
+    itemStack.set(DataComponents.BASE_COLOR, DyeColor.MAGENTA);
+    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
+    Registry<BannerPattern> bannerPatterns = minecraftRegistry.registryOrThrow(Registries.BANNER_PATTERN);
+    BannerPattern halfLeft = bannerPatterns.getOrThrow(BannerPatterns.HALF_VERTICAL);
+    BannerPattern topLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_LEFT);
+    BannerPattern topRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_RIGHT);
+    BannerPattern bottomLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_LEFT);
+    BannerPattern bottomRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_RIGHT);
+    itemStack.set(DataComponents.BANNER_PATTERNS,
+        new BannerPatternLayers(List.of(
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfLeft), DyeColor.BLACK),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topLeft), DyeColor.MAGENTA),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomLeft), DyeColor.MAGENTA),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topRight), DyeColor.BLACK),
+            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomRight), DyeColor.BLACK))));
+    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+    addModelData(itemStack);
+    return itemStack;
+  }
+
+}

internal/paper1_21_1/src/main/java/com/lishid/openinv/internal/paper1_21_1/player/PlayerManager.java

@@ -0,0 +1,55 @@
+package com.lishid.openinv.internal.paper1_21_1.player;
+
+import com.mojang.authlib.GameProfile;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ClientInformation;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.entity.player.ChatVisiblity;
+import org.bukkit.OfflinePlayer;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.logging.Logger;
+
+public class PlayerManager extends com.lishid.openinv.internal.paper1_21_4.player.PlayerManager {
+
+  public PlayerManager(@NotNull Logger logger) {
+    super(logger);
+  }
+
+  @Override
+  protected @NotNull ServerPlayer createNewPlayer(
+      @NotNull MinecraftServer server,
+      @NotNull ServerLevel worldServer,
+      @NotNull final OfflinePlayer offline) {
+    // See net.minecraft.server.players.PlayerList#canPlayerLogin(ServerLoginPacketListenerImpl, GameProfile)
+    // See net.minecraft.server.network.ServerLoginPacketListenerImpl#handleHello(ServerboundHelloPacket)
+    GameProfile profile = new GameProfile(offline.getUniqueId(),
+        offline.getName() != null ? offline.getName() : offline.getUniqueId().toString());
+
+    ClientInformation dummyInfo = new ClientInformation(
+        "en_us",
+        1, // Reduce distance just in case.
+        ChatVisiblity.HIDDEN, // Don't accept chat.
+        false,
+        ServerPlayer.DEFAULT_MODEL_CUSTOMIZATION,
+        ServerPlayer.DEFAULT_MAIN_HAND,
+        true,
+        false // Don't list in player list (not that this player is in the list anyway).
+    );
+
+    ServerPlayer entity = new ServerPlayer(server, worldServer, profile, dummyInfo);
+
+    try {
+      injectPlayer(entity);
+    } catch (IllegalAccessException e) {
+      logger.log(
+          java.util.logging.Level.WARNING,
+          e,
+          () -> "Unable to inject ServerPlayer, certain player data may be lost when saving!");
+    }
+
+    return entity;
+  }
+
+}

internal/paper1_21_3/build.gradle.kts

@@ -0,0 +1,27 @@
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+  implementation(project(":openinvadaptercommon"))
+  implementation(project(":openinvadapterpaper1_21_4"))
+
+  paperweight.paperDevBundle("1.21.3-R0.1-SNAPSHOT")
+}

internal/paper1_21_3/src/main/java/com/lishid/openinv/internal/paper1_21_3/InternalAccessor.java

@@ -0,0 +1,28 @@
+package com.lishid.openinv.internal.paper1_21_3;
+
+import com.lishid.openinv.internal.paper1_21_3.container.slot.placeholder.NumericDataPlaceholderLoader;
+import com.lishid.openinv.util.lang.LanguageManager;
+import org.bukkit.configuration.ConfigurationSection;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class InternalAccessor extends com.lishid.openinv.internal.paper1_21_4.InternalAccessor {
+
+  public InternalAccessor(@NotNull Logger logger, @NotNull LanguageManager lang) {
+    super(logger, lang);
+  }
+
+  @Override
+  public void reload(@NotNull ConfigurationSection config) {
+    ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new NumericDataPlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
+    }
+  }
+
+}

internal/paper1_21_3/src/main/java/com/lishid/openinv/internal/paper1_21_3/container/slot/placeholder/NumericDataPlaceholderLoader.java

@@ -0,0 +1,12 @@
+package com.lishid.openinv.internal.paper1_21_3.container.slot.placeholder;
+
+import com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder.CustomModelBase;
+import net.minecraft.world.item.component.CustomModelData;
+
+public class NumericDataPlaceholderLoader extends CustomModelBase {
+
+  public NumericDataPlaceholderLoader() {
+    super(new CustomModelData(9999));
+  }
+
+}

internal/paper1_21_4/build.gradle.kts

@@ -0,0 +1,26 @@
+plugins {
+  `openinv-base`
+  alias(libs.plugins.paperweight)
+}
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val paper = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "paper-api"
+      }
+    }
+    if (paper != null) {
+      select(paper)
+    }
+    because("module is written for Paper servers")
+  }
+}
+
+dependencies {
+  implementation(project(":openinvapi"))
+  implementation(project(":openinvcommon"))
+  implementation(project(":openinvadaptercommon"))
+
+  paperweight.paperDevBundle("1.21.4-R0.1-SNAPSHOT")
+}

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/InternalAccessor.java

@@ -1,19 +1,19 @@
-package com.lishid.openinv.internal.v1_21_R2;
+package com.lishid.openinv.internal.paper1_21_4;
 
 import com.lishid.openinv.internal.Accessor;
 import com.lishid.openinv.internal.IAnySilentContainer;
 import com.lishid.openinv.internal.ISpecialEnderChest;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.ISpecialPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.AnySilentContainer;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.Placeholders;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
+import com.lishid.openinv.internal.common.container.AnySilentContainer;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenEnderChest;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder.CustomModelPlaceholderLoader;
+import com.lishid.openinv.internal.paper1_21_4.player.PlayerManager;
 import com.lishid.openinv.util.lang.LanguageManager;
 import net.minecraft.world.Container;
 import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
 import org.jetbrains.annotations.NotNull;
@@ -24,7 +24,7 @@ import java.util.logging.Logger;
 
 public class InternalAccessor implements Accessor {
 
-  private final @NotNull Logger logger;
+  protected final @NotNull Logger logger;
   private final @NotNull PlayerManager manager;
   private final @NotNull AnySilentContainer anySilentContainer;
 
@@ -69,12 +69,11 @@ public class InternalAccessor implements Accessor {
   @Override
   public void reload(@NotNull ConfigurationSection config) {
     ConfigurationSection placeholders = config.getConfigurationSection("placeholders");
-    if (placeholders != null) {
-      try {
-        Placeholders.load(placeholders);
-      } catch (Exception e) {
-        logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
-      }
+    try {
+      // Reset placeholders to defaults and try to load configuration.
+      new CustomModelPlaceholderLoader().load(placeholders);
+    } catch (Exception e) {
+      logger.log(Level.WARNING, "Caught exception loading placeholder overrides!", e);
     }
   }
 

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/OpenEnderChest.java

@@ -0,0 +1,23 @@
+package com.lishid.openinv.internal.paper1_21_4.container;
+
+import com.lishid.openinv.internal.paper1_21_4.container.menu.OpenEnderChestMenu;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenEnderChest extends com.lishid.openinv.internal.common.container.OpenEnderChest{
+
+  public OpenEnderChest(@NotNull Player player) {
+    super(player);
+  }
+
+  public @Nullable AbstractContainerMenu createMenu(net.minecraft.world.entity.player.Player player, int i, boolean viewOnly) {
+    if (player instanceof ServerPlayer serverPlayer) {
+      return new OpenEnderChestMenu(this, serverPlayer, i, viewOnly);
+    }
+    return null;
+  }
+
+}

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/OpenInventory.java

@@ -0,0 +1,177 @@
+package com.lishid.openinv.internal.paper1_21_4.container;
+
+import com.lishid.openinv.internal.common.container.slot.ContentCrafting;
+import com.lishid.openinv.internal.common.container.slot.ContentCursor;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.ContentList;
+import com.lishid.openinv.internal.common.container.slot.ContentViewOnly;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
+import com.lishid.openinv.internal.paper1_21_4.container.menu.OpenInventoryMenu;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.ContentEquipment;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.ContentOffHand;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Container;
+import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+import net.minecraft.world.inventory.Slot;
+import net.minecraft.world.item.ItemStack;
+import org.bukkit.event.inventory.InventoryType;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenInventory extends com.lishid.openinv.internal.common.container.OpenInventory {
+
+  public OpenInventory(@NotNull org.bukkit.entity.Player bukkitPlayer) {
+    super(bukkitPlayer);
+  }
+
+  @Override
+  protected void setupSlots() {
+    // Top of inventory: Regular contents.
+    int nextIndex = addMainInventory();
+
+    // If inventory is expected size, we can arrange slots to be pretty.
+    Inventory ownerInv = owner.getInventory();
+    if (ownerInv.items.size() == 36
+        && ownerInv.armor.size() == 4
+        && ownerInv.offhand.size() == 1
+        && owner.inventoryMenu.getCraftSlots().getContainerSize() == 4) {
+      // Armor slots: Bottom left.
+      addArmor(36);
+      // Off-hand: Below chestplate.
+      addOffHand(46);
+      // Drop slot: Bottom right.
+      slots.set(53, new ContentDrop(owner));
+      // Cursor slot: Above drop.
+      slots.set(44, new ContentCursor(owner));
+
+      // Crafting is displayed in the bottom right corner.
+      // As we're using the pretty view, this is a 3x2.
+      addCrafting(41, true);
+      return;
+    }
+
+    // Otherwise we'll just add elements linearly.
+    nextIndex = addArmor(nextIndex);
+    nextIndex = addOffHand(nextIndex);
+    nextIndex = addCrafting(nextIndex, false);
+    slots.set(nextIndex, new ContentCursor(owner));
+    // Drop slot last.
+    slots.set(slots.size() - 1, new ContentDrop(owner));
+  }
+
+  private int addMainInventory() {
+    int listSize = owner.getInventory().items.size();
+    // Hotbar slots are 0-8. We want those to appear on the bottom of the inventory like a normal player inventory,
+    // so everything else needs to move up a row.
+    int hotbarDiff = listSize - 9;
+    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
+      InventoryType.SlotType type;
+      int invIndex;
+      if (localIndex < hotbarDiff) {
+        invIndex = localIndex + 9;
+        type = InventoryType.SlotType.CONTAINER;
+      } else {
+        type = InventoryType.SlotType.QUICKBAR;
+        invIndex = localIndex - hotbarDiff;
+      }
+
+      slots.set(localIndex, new ContentList(owner, invIndex, type) {
+        @Override
+        public void setHolder(@NotNull ServerPlayer holder) {
+          items = holder.getInventory().items;
+        }
+      });
+    }
+    return listSize;
+  }
+
+  private int addArmor(int startIndex) {
+    int listSize = owner.getInventory().armor.size();
+
+    for (int i = 0; i < listSize; ++i) {
+      // Armor slots go bottom to top; boots are slot 0, helmet is slot 3.
+      // Since we have to display horizontally due to space restrictions,
+      // making the left side the "top" is more user-friendly.
+      int armorIndex;
+      EquipmentSlot slot;
+      switch (i) {
+        case 3 -> {
+          armorIndex = 0;
+          slot = EquipmentSlot.FEET;
+        }
+        case 2 -> {
+          armorIndex = 1;
+          slot = EquipmentSlot.LEGS;
+        }
+        case 1 -> {
+          armorIndex = 2;
+          slot = EquipmentSlot.CHEST;
+        }
+        case 0 -> {
+          armorIndex = 3;
+          slot = EquipmentSlot.HEAD;
+        }
+        default -> {
+          // In the event that new armor slots are added, they can be placed at the end.
+          armorIndex = i;
+          slot = EquipmentSlot.MAINHAND;
+        }
+      }
+
+      slots.set(startIndex + i, new ContentEquipment(owner, armorIndex, slot));
+    }
+
+    return startIndex + listSize;
+  }
+
+  private int addOffHand(int startIndex) {
+    int listSize = owner.getInventory().offhand.size();
+    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
+      slots.set(startIndex + localIndex, new ContentOffHand(owner, localIndex));
+    }
+    return startIndex + listSize;
+  }
+
+  private int addCrafting(int startIndex, boolean pretty) {
+    int listSize = owner.inventoryMenu.getCraftSlots().getContents().size();
+    pretty &= listSize == 4;
+
+    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
+      // Pretty display is a 2x2 rather than linear.
+      // If index is in top row, grid is not 2x2, or pretty is disabled, just use current index.
+      // Otherwise, subtract 2 and add 9 to start in the same position on the next row.
+      int modIndex = startIndex + (localIndex < 2 || !pretty ? localIndex : localIndex + 7);
+
+      slots.set(modIndex, new ContentCrafting(owner, localIndex));
+    }
+
+    if (pretty) {
+      slots.set(startIndex + 2, new ContentViewOnly(owner) {
+        @Override
+        public Slot asSlot(Container container, int slot, int x, int y) {
+          return new SlotViewOnly(container, slot, x, y) {
+            @Override
+            public ItemStack getOrDefault() {
+              return Placeholders.craftingOutput;
+            }
+          };
+        }
+      });
+      slots.set(startIndex + 11, getCraftingResult(owner));
+    }
+
+    return startIndex + listSize;
+  }
+
+  public @Nullable AbstractContainerMenu createMenu(Player player, int i, boolean viewOnly) {
+    if (player instanceof ServerPlayer serverPlayer) {
+      return new OpenInventoryMenu(this, serverPlayer, i, viewOnly);
+    }
+    return null;
+  }
+
+}

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/bukkit/OpenPlayerInventory.java

@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R2.container.bukkit;
+package com.lishid.openinv.internal.paper1_21_4.container.bukkit;
 
 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
 import net.minecraft.core.NonNullList;
 import net.minecraft.world.entity.EquipmentSlot;
 import net.minecraft.world.entity.player.Inventory;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventory;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.entity.Player;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.ItemStack;
@@ -26,7 +26,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public ItemStack[] getContents() {
+  public ItemStack @NotNull [] getContents() {
     return asCraftMirror(getInventory().getOwnerHandle().getInventory().getContents());
   }
 
@@ -46,7 +46,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public ItemStack[] getStorageContents() {
+  public ItemStack @NotNull [] getStorageContents() {
     return asCraftMirror(getInventory().getOwnerHandle().getInventory().items);
   }
 
@@ -71,12 +71,12 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @NotNull ItemStack[] getArmorContents() {
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
     return asCraftMirror(getInventory().getOwnerHandle().getInventory().armor);
   }
 
   @Override
-  public void setArmorContents(@Nullable ItemStack[] items) {
+  public void setArmorContents(ItemStack @NotNull [] items) {
     NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().armor;
     int size = list.size();
     Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
@@ -86,12 +86,12 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @NotNull ItemStack[] getExtraContents() {
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
     return asCraftMirror(getInventory().getOwnerHandle().getInventory().offhand);
   }
 
   @Override
-  public void setExtraContents(@Nullable ItemStack[] items) {
+  public void setExtraContents(ItemStack @NotNull [] items) {
     NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().offhand;
     int size = list.size();
     Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
@@ -101,7 +101,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @Nullable ItemStack getHelmet() {
+  public @NotNull ItemStack getHelmet() {
     return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
         .getArmor(EquipmentSlot.HEAD.getIndex()));
   }
@@ -113,9 +113,9 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @Nullable ItemStack getChestplate() {
+  public @NotNull ItemStack getChestplate() {
     return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
-        .getArmor(EquipmentSlot.HEAD.getIndex()));
+        .getArmor(EquipmentSlot.CHEST.getIndex()));
   }
 
   @Override
@@ -125,7 +125,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @Nullable ItemStack getLeggings() {
+  public @NotNull ItemStack getLeggings() {
     return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
         .getArmor(EquipmentSlot.LEGS.getIndex()));
   }
@@ -137,7 +137,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @Nullable ItemStack getBoots() {
+  public @NotNull ItemStack getBoots() {
     return CraftItemStack.asCraftMirror(getInventory().getOwnerHandle().getInventory()
         .getArmor(EquipmentSlot.FEET.getIndex()));
   }
@@ -170,11 +170,13 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
     getInventory().getOwnerHandle().getInventory().offhand.set(0, CraftItemStack.asNMSCopy(item));
   }
 
+  @Deprecated
   @Override
   public @NotNull ItemStack getItemInHand() {
     return getItemInMainHand();
   }
 
+  @Deprecated
   @Override
   public void setItemInHand(@Nullable ItemStack stack) {
     setItemInMainHand(stack);
@@ -193,7 +195,7 @@ public class OpenPlayerInventory extends CraftInventory implements PlayerInvento
   }
 
   @Override
-  public @Nullable ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
+  public @NotNull ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
     return switch (slot) {
       case HAND -> getItemInMainHand();
       case OFF_HAND -> getItemInOffHand();

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/bukkit/OpenPlayerInventorySelf.java

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R3.container.bukkit;
+package com.lishid.openinv.internal.paper1_21_4.container.bukkit;
 
-import com.lishid.openinv.internal.v1_21_R3.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
 import org.bukkit.inventory.ItemStack;
 import org.jetbrains.annotations.NotNull;
 

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/menu/OpenChestMenu.java

@@ -1,11 +1,11 @@
-package com.lishid.openinv.internal.v1_21_R3.container.menu;
+package com.lishid.openinv.internal.paper1_21_4.container.menu;
 
 import com.google.common.base.Suppliers;
 import com.lishid.openinv.internal.ISpecialInventory;
 import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R3.container.bukkit.OpenDummyInventory;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.SlotPlaceholder;
-import com.lishid.openinv.internal.v1_21_R3.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyInventory;
+import com.lishid.openinv.internal.common.container.slot.SlotPlaceholder;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
 import it.unimi.dsi.fastutil.ints.IntArrayList;
 import it.unimi.dsi.fastutil.ints.IntList;
 import net.minecraft.server.level.ServerPlayer;
@@ -21,7 +21,7 @@ import net.minecraft.world.inventory.DataSlot;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -108,26 +108,14 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
     }
   }
 
-  public static @NotNull MenuType<ChestMenu> getChestMenuType(int inventorySize) {
-    inventorySize = ((int) Math.ceil(inventorySize / 9.0)) * 9;
-    return switch (inventorySize) {
-      case 9 -> MenuType.GENERIC_9x1;
-      case 18 -> MenuType.GENERIC_9x2;
-      case 27 -> MenuType.GENERIC_9x3;
-      case 36 -> MenuType.GENERIC_9x4;
-      case 45 -> MenuType.GENERIC_9x5;
-      case 54 -> MenuType.GENERIC_9x6;
-      default -> throw new IllegalArgumentException("Inventory size unsupported: " + inventorySize);
-    };
-  }
-
   protected void preSlotSetup() {}
 
   protected @NotNull Slot getUpperSlot(int index, int x, int y) {
+    Slot slot = new Slot(container, index, x, y);
     if (viewOnly) {
-      return new SlotViewOnly(container, index, x, y);
+      return SlotViewOnly.wrap(slot);
     }
-    return new Slot(container, index, x, y);
+    return slot;
   }
 
 
@@ -176,9 +164,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
 
   private int getTopSize(ServerPlayer viewer) {
     MenuType<?> menuType = getType();
-    if (menuType == null) {
-      throw new IllegalStateException("MenuType cannot be null!");
-    } else if (menuType == MenuType.GENERIC_9x1) {
+    if (menuType == MenuType.GENERIC_9x1) {
       return 9;
     } else if (menuType == MenuType.GENERIC_9x2) {
       return 18;
@@ -284,7 +270,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public void clicked(int i, int j, ClickType clickType, Player player) {
+  public void clicked(int i, int j, @NotNull ClickType clickType, @NotNull Player player) {
     if (viewOnly) {
       if (clickType == ClickType.QUICK_CRAFT) {
         sendAllDataToRemote();
@@ -295,13 +281,13 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public boolean stillValid(Player player) {
+  public boolean stillValid(@NotNull Player player) {
     return true;
   }
 
   // Overrides from here on are purely to modify the sync process to send placeholder items.
   @Override
-  protected Slot addSlot(Slot slot) {
+  protected @NotNull Slot addSlot(@NotNull Slot slot) {
     slot.index = this.slots.size();
     this.slots.add(slot);
     this.lastSlots.add(ItemStack.EMPTY);
@@ -310,7 +296,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  protected DataSlot addDataSlot(DataSlot dataSlot) {
+  protected @NotNull DataSlot addDataSlot(@NotNull DataSlot dataSlot) {
     this.dataSlots.add(dataSlot);
     this.remoteDataSlots.add(0);
     return dataSlot;
@@ -324,7 +310,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public void addSlotListener(ContainerListener containerListener) {
+  public void addSlotListener(@NotNull ContainerListener containerListener) {
     if (!this.containerListeners.contains(containerListener)) {
       this.containerListeners.add(containerListener);
       this.broadcastChanges();
@@ -332,7 +318,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public void setSynchronizer(ContainerSynchronizer containerSynchronizer) {
+  public void setSynchronizer(@NotNull ContainerSynchronizer containerSynchronizer) {
     this.synchronizer = containerSynchronizer;
     this.sendAllDataToRemote();
   }
@@ -364,7 +350,7 @@ public abstract class OpenChestMenu<T extends Container & ISpecialInventory & In
   }
 
   @Override
-  public void removeSlotListener(ContainerListener containerListener) {
+  public void removeSlotListener(@NotNull ContainerListener containerListener) {
     this.containerListeners.remove(containerListener);
   }
 

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/menu/OpenEnderChestMenu.java

@@ -1,6 +1,6 @@
-package com.lishid.openinv.internal.v1_21_R2.container.menu;
+package com.lishid.openinv.internal.paper1_21_4.container.menu;
 
-import com.lishid.openinv.internal.v1_21_R2.container.OpenEnderChest;
+import com.lishid.openinv.internal.common.container.OpenEnderChest;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.inventory.Slot;
@@ -14,11 +14,17 @@ public class OpenEnderChestMenu extends OpenChestMenu<OpenEnderChest> {
       @NotNull ServerPlayer viewer,
       int containerId,
       boolean viewOnly) {
-    super(getChestMenuType(enderChest.getContainerSize()), containerId, enderChest, viewer, viewOnly);
+    super(
+        com.lishid.openinv.internal.common.container.menu.OpenChestMenu.getChestMenuType(enderChest.getContainerSize()),
+        containerId,
+        enderChest,
+        viewer,
+        viewOnly
+    );
   }
 
   @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
     if (viewOnly) {
       return ItemStack.EMPTY;
     }

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/menu/OpenInventoryMenu.java

@@ -1,12 +1,12 @@
-package com.lishid.openinv.internal.v1_21_R2.container.menu;
+package com.lishid.openinv.internal.paper1_21_4.container.menu;
 
 import com.google.common.base.Preconditions;
-import com.lishid.openinv.internal.v1_21_R2.container.OpenInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenDummyPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenPlayerInventorySelf;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.common.container.bukkit.OpenDummyPlayerInventory;
+import com.lishid.openinv.internal.common.container.slot.ContentDrop;
+import com.lishid.openinv.internal.common.container.slot.SlotViewOnly;
+import com.lishid.openinv.internal.paper1_21_4.container.OpenInventory;
+import com.lishid.openinv.internal.paper1_21_4.container.bukkit.OpenPlayerInventorySelf;
+import com.lishid.openinv.internal.paper1_21_4.container.slot.ContentEquipment;
 import com.lishid.openinv.util.Permissions;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.entity.EquipmentSlot;
@@ -15,8 +15,8 @@ import net.minecraft.world.inventory.ChestMenu;
 import net.minecraft.world.inventory.MenuType;
 import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventoryView;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftItemStack;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
@@ -39,7 +39,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
       size = ((int) Math.ceil(size / 9.0)) * 9;
     }
 
-    return getChestMenuType(size);
+    return com.lishid.openinv.internal.common.container.menu.OpenChestMenu.getChestMenuType(size);
   }
 
   @Override
@@ -195,7 +195,7 @@ public class OpenInventoryMenu extends OpenChestMenu<OpenInventory> {
   }
 
   @Override
-  public ItemStack quickMoveStack(Player player, int index) {
+  public @NotNull ItemStack quickMoveStack(@NotNull Player player, int index) {
     if (viewOnly) {
       return ItemStack.EMPTY;
     }

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/slot/ContentEquipment.java

@@ -1,6 +1,8 @@
-package com.lishid.openinv.internal.v1_21_R3.container.slot;
+package com.lishid.openinv.internal.paper1_21_4.container.slot;
 
-import com.lishid.openinv.internal.v1_21_R3.container.Placeholders;
+import com.lishid.openinv.internal.common.container.slot.ContentList;
+import com.lishid.openinv.internal.common.container.slot.SlotPlaceholder;
+import com.lishid.openinv.internal.common.container.slot.placeholder.Placeholders;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.EquipmentSlot;
@@ -65,12 +67,12 @@ public class ContentEquipment extends ContentList {
     }
 
     @Override
-    public boolean mayPlace(ItemStack var0) {
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
       if (viewer == null) {
         return true;
       }
 
-      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(var0) == equipmentSlot;
+      return equipmentSlot == EquipmentSlot.OFFHAND || viewer.getEquipmentSlotForItem(itemStack) == equipmentSlot;
     }
 
   }

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/slot/ContentOffHand.java

@@ -1,8 +1,11 @@
-package com.lishid.openinv.internal.v1_21_R3.container.slot;
+package com.lishid.openinv.internal.paper1_21_4.container.slot;
 
+import com.lishid.openinv.internal.common.player.OpenPlayer;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.Container;
 import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.InventoryMenu;
 import net.minecraft.world.inventory.Slot;
 import org.bukkit.event.inventory.InventoryType;
 import org.jetbrains.annotations.NotNull;
@@ -34,10 +37,13 @@ public class ContentOffHand extends ContentEquipment {
     return new SlotEquipment(container, slot, x, y) {
       @Override
       public void setChanged() {
-        if (holder.connection != null
-            && !holder.connection.isDisconnected()
-            && holder.containerMenu != holder.inventoryMenu) {
-          holder.resendItemInHands();
+        if (OpenPlayer.isConnected(holder.connection) && holder.containerMenu != holder.inventoryMenu) {
+          holder.connection.send(
+              new ClientboundContainerSetSlotPacket(
+                  holder.inventoryMenu.containerId,
+                  holder.inventoryMenu.incrementStateId(),
+                  InventoryMenu.SHIELD_SLOT,
+                  holder.getOffhandItem()));
         }
       }
     };

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/slot/placeholder/CustomModelBase.java

@@ -0,0 +1,41 @@
+package com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder;
+
+import com.lishid.openinv.internal.common.container.slot.placeholder.PlaceholderLoaderBase;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.TagParser;
+import net.minecraft.util.Unit;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.component.CustomModelData;
+import net.minecraft.world.item.component.DyedItemColor;
+import org.jetbrains.annotations.NotNull;
+
+public class CustomModelBase extends PlaceholderLoaderBase {
+
+  private final @NotNull CustomModelData defaultCustomModelData;
+
+  public CustomModelBase(@NotNull CustomModelData defaultCustomModelData) {
+    this.defaultCustomModelData = defaultCustomModelData;
+  }
+
+  @Override
+  protected @NotNull CompoundTag parseTag(@NotNull String itemText) throws Exception {
+    return TagParser.parseTag(itemText);
+  }
+
+  @Override
+  protected void addModelData(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, defaultCustomModelData);
+  }
+
+  @Override
+  protected void hideTooltip(@NotNull ItemStack itemStack) {
+    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
+  }
+
+  @Override
+  protected DyedItemColor getDye(int rgb) {
+    return new DyedItemColor(rgb, false);
+  }
+
+}

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/container/slot/placeholder/CustomModelPlaceholderLoader.java

@@ -0,0 +1,13 @@
+package com.lishid.openinv.internal.paper1_21_4.container.slot.placeholder;
+
+import net.minecraft.world.item.component.CustomModelData;
+
+import java.util.List;
+
+public class CustomModelPlaceholderLoader extends CustomModelBase {
+
+  public CustomModelPlaceholderLoader() {
+    super(new CustomModelData(List.of(), List.of(), List.of("openinv:custom"), List.of()));
+  }
+
+}

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/player/OpenPlayer.java

@@ -0,0 +1,35 @@
+package com.lishid.openinv.internal.paper1_21_4.player;
+
+import com.lishid.openinv.internal.common.player.PlayerManager;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ServerPlayer;
+import org.bukkit.craftbukkit.CraftServer;
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenPlayer extends com.lishid.openinv.internal.common.player.OpenPlayer {
+
+  protected OpenPlayer(CraftServer server, ServerPlayer entity,
+      PlayerManager manager) {
+    super(server, entity, manager);
+  }
+
+  @Contract("null -> new")
+  @Override
+  protected @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
+    if (oldData == null) {
+      return new CompoundTag();
+    }
+
+    // Copy old data. This is a deep clone, so operating on it should be safe.
+    oldData = oldData.copy();
+
+    // Remove vanilla/server data that is not written every time.
+    oldData.getAllKeys()
+        .removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit"));
+
+    return oldData;
+  }
+
+}

internal/paper1_21_4/src/main/java/com/lishid/openinv/internal/paper1_21_4/player/PlayerManager.java

@@ -0,0 +1,70 @@
+package com.lishid.openinv.internal.paper1_21_4.player;
+
+import com.mojang.serialization.Dynamic;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtOps;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.dimension.DimensionType;
+import org.bukkit.Bukkit;
+import org.bukkit.World;
+import org.bukkit.craftbukkit.CraftWorld;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.UUID;
+import java.util.logging.Logger;
+
+public class PlayerManager extends com.lishid.openinv.internal.common.player.PlayerManager {
+
+  public PlayerManager(@NotNull Logger logger) {
+    super(logger);
+  }
+
+  protected void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
+    // See PlayerList#placeNewPlayer
+    World bukkitWorld;
+    if (loadedData.contains("WorldUUIDMost") && loadedData.contains("WorldUUIDLeast")) {
+      // Modern Bukkit world.
+      bukkitWorld = Bukkit.getServer().getWorld(new UUID(loadedData.getLong("WorldUUIDMost"), loadedData.getLong("WorldUUIDLeast")));
+    } else if (loadedData.contains("world", net.minecraft.nbt.Tag.TAG_STRING)) {
+      // Legacy Bukkit world.
+      bukkitWorld = Bukkit.getServer().getWorld(loadedData.getString("world"));
+    } else {
+      // Vanilla player data.
+      DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
+          .resultOrPartial(logger::warning)
+          .map(player.server::getLevel)
+          // If ServerLevel exists, set, otherwise move to spawn.
+          .ifPresentOrElse(player::setServerLevel, () -> spawnInDefaultWorld(player));
+      return;
+    }
+    if (bukkitWorld == null) {
+      spawnInDefaultWorld(player);
+      return;
+    }
+    player.setServerLevel(((CraftWorld) bukkitWorld).getHandle());
+  }
+
+  @Override
+  protected void spawnInDefaultWorld(ServerPlayer player) {
+    ServerLevel level = player.server.getLevel(Level.OVERWORLD);
+    if (level != null) {
+      // Adjust player to default spawn (in keeping with Paper handling) when world not found.
+      player.moveTo(player.adjustSpawnLocation(level, level.getSharedSpawnPos()).getBottomCenter(), level.getSharedSpawnAngle(), 0.0F);
+      player.spawnIn(level);
+    } else {
+      logger.warning("Tried to load player with invalid world when no fallback was available!");
+    }
+  }
+
+  protected void injectPlayer(ServerPlayer player) throws IllegalAccessException {
+    if (bukkitEntity == null) {
+      return;
+    }
+
+    bukkitEntity.setAccessible(true);
+    bukkitEntity.set(player, new OpenPlayer(player.server.server, player, this));
+  }
+
+}

internal/spigot/build.gradle.kts

@@ -0,0 +1,44 @@
+import com.github.jikoo.openinv.SpigotDependencyExtension
+import com.github.jikoo.openinv.SpigotReobf
+import com.github.jikoo.openinv.SpigotSetup
+
+plugins {
+  `openinv-base`
+  alias(libs.plugins.shadow)
+}
+
+apply<SpigotSetup>()
+apply<SpigotReobf>()
+
+val spigotVer = "1.21.5-R0.1-SNAPSHOT"
+// Used by common adapter to relocate Craftbukkit classes to a versioned package.
+rootProject.extra["craftbukkitPackage"] = "v1_21_R4"
+
+configurations.all {
+  resolutionStrategy.capabilitiesResolution.withCapability("org.spigotmc:spigot-api") {
+    val spigot = candidates.firstOrNull {
+      it.id.let {
+        id -> id is ModuleComponentIdentifier && id.module == "spigot-api"
+      }
+    }
+    if (spigot != null) {
+      select(spigot)
+    }
+    because("module is written for Spigot servers")
+  }
+}
+
+dependencies {
+  compileOnly(libs.spigotapi)
+  extensions.getByType(SpigotDependencyExtension::class.java).version = spigotVer
+
+  compileOnly(project(":openinvapi"))
+  compileOnly(project(":openinvcommon"))
+
+  // Reduce duplicate code by lightly remapping common adapter.
+  implementation(project(":openinvadaptercommon", configuration = "spigotRelocated"))
+}
+
+tasks.shadowJar {
+  relocate("com.lishid.openinv.internal.common", "com.lishid.openinv.internal.reobf")
+}

internal/spigot/src/main/java/com/lishid/openinv/internal/reobf/container/AnySilentContainer.java

@@ -0,0 +1,194 @@
+package com.lishid.openinv.internal.reobf.container;
+
+import com.lishid.openinv.internal.AnySilentContainerBase;
+import com.lishid.openinv.internal.reobf.container.menu.OpenChestMenu;
+import com.lishid.openinv.internal.reobf.player.PlayerManager;
+import com.lishid.openinv.util.ReflectionHelper;
+import com.lishid.openinv.util.lang.LanguageManager;
+import net.minecraft.core.BlockPos;
+import net.minecraft.network.chat.Component;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.ServerPlayerGameMode;
+import net.minecraft.world.MenuProvider;
+import net.minecraft.world.SimpleMenuProvider;
+import net.minecraft.world.inventory.ChestMenu;
+import net.minecraft.world.inventory.MenuType;
+import net.minecraft.world.inventory.PlayerEnderChestContainer;
+import net.minecraft.world.level.GameType;
+import net.minecraft.world.level.block.BarrelBlock;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.ChestBlock;
+import net.minecraft.world.level.block.ShulkerBoxBlock;
+import net.minecraft.world.level.block.TrappedChestBlock;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.entity.EnderChestBlockEntity;
+import net.minecraft.world.level.block.entity.RandomizableContainerBlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import org.bukkit.GameMode;
+import org.bukkit.Material;
+import org.bukkit.Statistic;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.lang.reflect.Field;
+import java.util.logging.Logger;
+
+public class AnySilentContainer extends AnySilentContainerBase {
+
+  private final @NotNull Logger logger;
+  private final @NotNull LanguageManager lang;
+  private @Nullable Field serverPlayerGameModeGameType;
+
+  public AnySilentContainer(@NotNull Logger logger, @NotNull LanguageManager lang) {
+    this.logger = logger;
+    this.lang = lang;
+    try {
+      try {
+        this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("gameModeForPlayer");
+        this.serverPlayerGameModeGameType.setAccessible(true);
+      } catch (NoSuchFieldException e) {
+        logger.warning("The field ServerPlayerGameMode#gameModeForPlayer is no longer present!");
+        logger.warning("Please report this at https://github.com/Jikoo/OpenInv/issues");
+        logger.warning("Attempting to fall through using reflection. Please verify that SilentContainer does not fail.");
+        // N.B. gameModeForPlayer is (for now) declared before previousGameModeForPlayer so silent shouldn't break.
+        this.serverPlayerGameModeGameType = ReflectionHelper.grabFieldByType(ServerPlayerGameMode.class, GameType.class);
+      }
+    } catch (SecurityException e) {
+      logger.warning("Unable to directly write player game mode! SilentContainer will fail.");
+      logger.log(java.util.logging.Level.WARNING, "Error obtaining GameType field", e);
+    }
+  }
+
+  @Override
+  public boolean activateContainer(
+      @NotNull final Player bukkitPlayer,
+      final boolean silentchest,
+      @NotNull final org.bukkit.block.Block bukkitBlock) {
+
+    // Silent ender chest is API-only
+    if (silentchest && bukkitBlock.getType() == Material.ENDER_CHEST) {
+      bukkitPlayer.openInventory(bukkitPlayer.getEnderChest());
+      bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
+      return true;
+    }
+
+    ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
+
+    final net.minecraft.world.level.Level level = player.level();
+    final BlockPos blockPos = new BlockPos(bukkitBlock.getX(), bukkitBlock.getY(), bukkitBlock.getZ());
+    final BlockEntity blockEntity = level.getBlockEntity(blockPos);
+
+    if (blockEntity == null) {
+      return false;
+    }
+
+    if (blockEntity instanceof EnderChestBlockEntity enderChestTile) {
+      // Anychest ender chest. See net.minecraft.world.level.block.EnderChestBlock
+      PlayerEnderChestContainer enderChest = player.getEnderChestInventory();
+      enderChest.setActiveChest(enderChestTile);
+      player.openMenu(new SimpleMenuProvider((containerCounter, playerInventory, ignored) -> {
+        MenuType<?> containers = OpenChestMenu.getChestMenuType(enderChest.getContainerSize());
+        int rows = enderChest.getContainerSize() / 9;
+        return new ChestMenu(containers, containerCounter, playerInventory, enderChest, rows);
+      }, Component.translatable("container.enderchest")));
+      bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
+      return true;
+    }
+
+    if (!(blockEntity instanceof MenuProvider menuProvider)) {
+      return false;
+    }
+
+    BlockState blockState = level.getBlockState(blockPos);
+    Block block = blockState.getBlock();
+
+    if (block instanceof ChestBlock chestBlock) {
+
+      // boolean flag: do not check if chest is blocked
+      menuProvider = chestBlock.getMenuProvider(blockState, level, blockPos, true);
+
+      if (menuProvider == null) {
+        lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
+        return false;
+      }
+
+      if (block instanceof TrappedChestBlock) {
+        bukkitPlayer.incrementStatistic(Statistic.TRAPPED_CHEST_TRIGGERED);
+      } else {
+        bukkitPlayer.incrementStatistic(Statistic.CHEST_OPENED);
+      }
+    }
+
+    if (block instanceof ShulkerBoxBlock) {
+      bukkitPlayer.incrementStatistic(Statistic.SHULKER_BOX_OPENED);
+    }
+
+    if (block instanceof BarrelBlock) {
+      bukkitPlayer.incrementStatistic(Statistic.OPEN_BARREL);
+    }
+
+    // AnyChest only - SilentChest not active, container unsupported, or unnecessary.
+    if (!silentchest || player.gameMode.getGameModeForPlayer() == GameType.SPECTATOR) {
+      player.openMenu(menuProvider);
+      return true;
+    }
+
+    // SilentChest requires access to setting players' game mode directly.
+    if (this.serverPlayerGameModeGameType == null) {
+      return false;
+    }
+
+    if (blockEntity instanceof RandomizableContainerBlockEntity lootable) {
+      if (lootable.lootTable != null) {
+        lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
+        return false;
+      }
+    }
+
+    GameType gameType = player.gameMode.getGameModeForPlayer();
+    this.forceGameType(player, GameType.SPECTATOR);
+    player.openMenu(menuProvider);
+    this.forceGameType(player, gameType);
+    return true;
+  }
+
+  @Override
+  public void deactivateContainer(@NotNull final Player bukkitPlayer) {
+    if (this.serverPlayerGameModeGameType == null || bukkitPlayer.getGameMode() == GameMode.SPECTATOR) {
+      return;
+    }
+
+    ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
+
+    // Force game mode change without informing plugins or players.
+    // Regular game mode set calls GameModeChangeEvent and is cancellable.
+    GameType gameType = player.gameMode.getGameModeForPlayer();
+    this.forceGameType(player, GameType.SPECTATOR);
+
+    // ServerPlayer#closeContainer cannot be called without entering an
+    // infinite loop because this method is called during inventory close.
+    // From ServerPlayer#closeContainer -> CraftEventFactory#handleInventoryCloseEvent
+    player.containerMenu.transferTo(player.inventoryMenu, player.getBukkitEntity());
+    // From ServerPlayer#closeContainer
+    player.doCloseContainer();
+    // Regular inventory close will handle the rest - packet sending, etc.
+
+    // Revert forced game mode.
+    this.forceGameType(player, gameType);
+  }
+
+  private void forceGameType(final ServerPlayer player, final GameType gameMode) {
+    if (this.serverPlayerGameModeGameType == null) {
+      // No need to warn repeatedly, error on startup and lack of function should be enough.
+      return;
+    }
+    try {
+      this.serverPlayerGameModeGameType.setAccessible(true);
+      this.serverPlayerGameModeGameType.set(player.gameMode, gameMode);
+    } catch (IllegalArgumentException | IllegalAccessException e) {
+      logger.log(java.util.logging.Level.WARNING, "Error bypassing GameModeChangeEvent", e);
+    }
+  }
+
+}

internal/spigot/src/main/java/com/lishid/openinv/internal/reobf/container/bukkit/OpenPlayerInventory.java

@@ -0,0 +1,188 @@
+package com.lishid.openinv.internal.reobf.container.bukkit;
+
+import com.google.common.base.Preconditions;
+import com.lishid.openinv.internal.reobf.container.OpenInventory;
+import net.minecraft.core.NonNullList;
+import net.minecraft.world.entity.player.Inventory;
+import org.bukkit.craftbukkit.v1_21_R4.inventory.CraftInventory;
+import org.bukkit.craftbukkit.v1_21_R4.inventory.CraftItemStack;
+import org.bukkit.entity.Player;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.inventory.PlayerInventory;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class OpenPlayerInventory extends CraftInventory implements PlayerInventory {
+
+  public OpenPlayerInventory(@NotNull OpenInventory inventory) {
+    super(inventory);
+  }
+
+  @Override
+  public @NotNull OpenInventory getInventory() {
+    return (OpenInventory) super.getInventory();
+  }
+
+  @Override
+  public ItemStack @NotNull [] getContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getContents());
+  }
+
+  @Override
+  public void setContents(ItemStack[] items) {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    int size = internal.getContainerSize();
+    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
+
+    for (int index = 0; index < size; ++index) {
+      if (index < items.length) {
+        internal.setItem(index, CraftItemStack.asNMSCopy(items[index]));
+      } else {
+        internal.setItem(index, net.minecraft.world.item.ItemStack.EMPTY);
+      }
+    }
+  }
+
+  @Override
+  public ItemStack @NotNull [] getStorageContents() {
+    return asCraftMirror(getInventory().getOwnerHandle().getInventory().getNonEquipmentItems());
+  }
+
+  @Override
+  public void setStorageContents(ItemStack[] items) throws IllegalArgumentException {
+    NonNullList<net.minecraft.world.item.ItemStack> list = getInventory().getOwnerHandle().getInventory().getNonEquipmentItems();
+    int size = list.size();
+    Preconditions.checkArgument(items.length <= size, "items.length must be <= %s", size);
+    for (int index = 0; index < items.length; ++index) {
+      list.set(index, CraftItemStack.asNMSCopy(items[index]));
+    }
+  }
+
+  @Override
+  public @NotNull InventoryType getType() {
+    return InventoryType.PLAYER;
+  }
+
+  @Override
+  public @NotNull Player getHolder() {
+    return getInventory().getOwner();
+  }
+
+  @Override
+  public @NotNull ItemStack @NotNull [] getArmorContents() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getArmorContents();
+  }
+
+  @Override
+  public void setArmorContents(ItemStack @NotNull [] items) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setArmorContents(items);
+  }
+
+  @Override
+  public @NotNull ItemStack @NotNull [] getExtraContents() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getExtraContents();
+  }
+
+  @Override
+  public void setExtraContents(ItemStack @NotNull [] items) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setExtraContents(items);
+  }
+
+  @Override
+  public @Nullable ItemStack getHelmet() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getHelmet();
+  }
+
+  @Override
+  public void setHelmet(@Nullable ItemStack helmet) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setHelmet(helmet);
+  }
+
+  @Override
+  public @Nullable ItemStack getChestplate() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getChestplate();
+  }
+
+  @Override
+  public void setChestplate(@Nullable ItemStack chestplate) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setChestplate(chestplate);
+  }
+
+  @Override
+  public @Nullable ItemStack getLeggings() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getLeggings();
+  }
+
+  @Override
+  public void setLeggings(@Nullable ItemStack leggings) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setLeggings(leggings);
+  }
+
+  @Override
+  public @Nullable ItemStack getBoots() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getBoots();
+  }
+
+  @Override
+  public void setBoots(@Nullable ItemStack boots) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setBoots(boots);
+  }
+
+  @Override
+  public @NotNull ItemStack getItemInMainHand() {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    return CraftItemStack.asCraftMirror(internal.getSelectedItem());
+  }
+
+  @Override
+  public void setItemInMainHand(@Nullable ItemStack item) {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    internal.setSelectedItem(CraftItemStack.asNMSCopy(item));
+  }
+
+  @Override
+  public @NotNull ItemStack getItemInOffHand() {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getItemInOffHand();
+  }
+
+  @Override
+  public void setItemInOffHand(@Nullable ItemStack item) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setItemInOffHand(item);
+  }
+
+  @Deprecated
+  @Override
+  public @NotNull ItemStack getItemInHand() {
+    return getItemInMainHand();
+  }
+
+  @Deprecated
+  @Override
+  public void setItemInHand(@Nullable ItemStack stack) {
+    setItemInMainHand(stack);
+  }
+
+  @Override
+  public int getHeldItemSlot() {
+    Inventory internal = getInventory().getOwnerHandle().getInventory();
+    return internal.getNonEquipmentItems().size() - 9 + internal.getSelectedSlot();
+  }
+
+  @Override
+  public void setHeldItemSlot(int slot) {
+    slot %= 9;
+    getInventory().getOwnerHandle().getInventory().setSelectedSlot(slot);
+  }
+
+  @Override
+  public @Nullable ItemStack getItem(@NotNull org.bukkit.inventory.EquipmentSlot slot) {
+    return getInventory().getOwnerHandle().getBukkitEntity().getInventory().getItem(slot);
+  }
+
+  @Override
+  public void setItem(@NotNull org.bukkit.inventory.EquipmentSlot slot, @Nullable ItemStack item) {
+    getInventory().getOwnerHandle().getBukkitEntity().getInventory().setItem(slot, item);
+  }
+
+}

internal/spigot/src/main/java/com/lishid/openinv/internal/reobf/container/slot/ContentEquipment.java

@@ -0,0 +1,116 @@
+package com.lishid.openinv.internal.reobf.container.slot;
+
+import com.lishid.openinv.internal.reobf.container.slot.placeholder.Placeholders;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Container;
+import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.Slot;
+import net.minecraft.world.item.ItemStack;
+import org.bukkit.craftbukkit.v1_21_R4.CraftEquipmentSlot;
+import org.bukkit.craftbukkit.v1_21_R4.inventory.CraftItemStack;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.PlayerInventory;
+import org.jetbrains.annotations.NotNull;
+
+public class ContentEquipment implements Content {
+
+  private PlayerInventory equipment;
+  private final ItemStack placeholder;
+  private final org.bukkit.inventory.EquipmentSlot equipmentSlot;
+
+  public ContentEquipment(ServerPlayer holder, EquipmentSlot equipmentSlot) {
+    setHolder(holder);
+    placeholder = switch (equipmentSlot) {
+      case HEAD -> Placeholders.emptyHelmet;
+      case CHEST -> Placeholders.emptyChestplate;
+      case LEGS -> Placeholders.emptyLeggings;
+      case FEET -> Placeholders.emptyBoots;
+      default -> Placeholders.emptyOffHand;
+    };
+    this.equipmentSlot = CraftEquipmentSlot.getSlot(equipmentSlot);
+  }
+
+  @Override
+  public void setHolder(@NotNull ServerPlayer holder) {
+    this.equipment = holder.getBukkitEntity().getInventory();
+  }
+
+  @Override
+  public ItemStack get() {
+    return CraftItemStack.asNMSCopy(equipment.getItem(equipmentSlot));
+  }
+
+  @Override
+  public ItemStack remove() {
+    org.bukkit.inventory.ItemStack old = equipment.getItem(equipmentSlot);
+    equipment.setItem(equipmentSlot, null);
+    return CraftItemStack.asNMSCopy(old);
+  }
+
+  @Override
+  public ItemStack removePartial(int amount) {
+    if (amount <= 0) {
+      return ItemStack.EMPTY;
+    }
+    ItemStack current = get();
+    if (current.isEmpty()) {
+      return ItemStack.EMPTY;
+    }
+    ItemStack split = current.split(amount);
+    set(current);
+    return split;
+  }
+
+  @Override
+  public void set(ItemStack itemStack) {
+    equipment.setItem(equipmentSlot, CraftItemStack.asCraftMirror(itemStack));
+  }
+
+  @Override
+  public Slot asSlot(Container container, int slot, int x, int y) {
+    return new SlotEquipment(container, slot, x, y);
+  }
+
+  @Override
+  public InventoryType.SlotType getSlotType() {
+    return InventoryType.SlotType.ARMOR;
+  }
+
+  public class SlotEquipment extends SlotPlaceholder {
+
+    private ServerPlayer viewer;
+
+    SlotEquipment(Container container, int index, int x, int y) {
+      super(container, index, x, y);
+    }
+
+    @Override
+    public ItemStack getOrDefault() {
+      ItemStack itemStack = getItem();
+      if (!itemStack.isEmpty()) {
+        return itemStack;
+      }
+      return placeholder;
+    }
+
+    public EquipmentSlot getEquipmentSlot() {
+      return CraftEquipmentSlot.getNMS(equipmentSlot);
+    }
+
+    public void onlyEquipmentFor(ServerPlayer viewer) {
+      this.viewer = viewer;
+    }
+
+    @Override
+    public boolean mayPlace(@NotNull ItemStack itemStack) {
+      if (viewer == null) {
+        return true;
+      }
+
+      return equipmentSlot == org.bukkit.inventory.EquipmentSlot.OFF_HAND
+          || viewer.getEquipmentSlotForItem(itemStack) == CraftEquipmentSlot.getNMS(equipmentSlot);
+    }
+
+  }
+
+}

internal/spigot/src/main/java/com/lishid/openinv/internal/reobf/container/slot/ContentOffHand.java

@@ -0,0 +1,49 @@
+package com.lishid.openinv.internal.reobf.container.slot;
+
+import com.lishid.openinv.internal.reobf.player.OpenPlayer;
+import net.minecraft.network.protocol.game.ClientboundContainerSetSlotPacket;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Container;
+import net.minecraft.world.entity.EquipmentSlot;
+import net.minecraft.world.inventory.InventoryMenu;
+import net.minecraft.world.inventory.Slot;
+import org.bukkit.event.inventory.InventoryType;
+import org.jetbrains.annotations.NotNull;
+
+public class ContentOffHand extends ContentEquipment {
+
+  private ServerPlayer holder;
+
+  public ContentOffHand(ServerPlayer holder) {
+    super(holder, EquipmentSlot.OFFHAND);
+  }
+
+  @Override
+  public void setHolder(@NotNull ServerPlayer holder) {
+    super.setHolder(holder);
+    this.holder = holder;
+  }
+
+  @Override
+  public InventoryType.SlotType getSlotType() {
+    return InventoryType.SlotType.QUICKBAR;
+  }
+
+  @Override
+  public Slot asSlot(Container container, int slot, int x, int y) {
+    return new SlotEquipment(container, slot, x, y) {
+      @Override
+      public void setChanged() {
+        if (OpenPlayer.isConnected(holder.connection) && holder.containerMenu != holder.inventoryMenu) {
+          holder.connection.send(
+              new ClientboundContainerSetSlotPacket(
+                  holder.inventoryMenu.containerId,
+                  holder.inventoryMenu.incrementStateId(),
+                  InventoryMenu.SHIELD_SLOT,
+                  holder.getOffhandItem()));
+        }
+      }
+    };
+  }
+
+}

internal/spigot/src/main/java/com/lishid/openinv/internal/reobf/player/PlayerManager.java

@@ -1,12 +1,10 @@
-package com.lishid.openinv.internal.v1_21_R3.player;
+package com.lishid.openinv.internal.reobf.player;
 
 import com.lishid.openinv.internal.ISpecialInventory;
-import com.lishid.openinv.internal.v1_21_R3.container.OpenEnderChest;
-import com.lishid.openinv.internal.v1_21_R3.container.OpenInventory;
+import com.lishid.openinv.internal.reobf.container.OpenEnderChest;
+import com.lishid.openinv.internal.reobf.container.OpenInventory;
 import com.mojang.authlib.GameProfile;
-import com.mojang.serialization.Dynamic;
 import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.NbtOps;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.protocol.game.ClientboundOpenScreenPacket;
 import net.minecraft.server.MinecraftServer;
@@ -18,37 +16,22 @@ import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.player.ChatVisiblity;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.level.Level;
-import net.minecraft.world.level.dimension.DimensionType;
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.Server;
-import org.bukkit.World;
-import org.bukkit.craftbukkit.v1_21_R3.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R3.CraftWorld;
-import org.bukkit.craftbukkit.v1_21_R3.entity.CraftPlayer;
-import org.bukkit.craftbukkit.v1_21_R3.event.CraftEventFactory;
+import org.bukkit.craftbukkit.v1_21_R4.CraftServer;
+import org.bukkit.craftbukkit.v1_21_R4.entity.CraftPlayer;
+import org.bukkit.craftbukkit.v1_21_R4.event.CraftEventFactory;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.InventoryView;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.lang.reflect.Field;
-import java.util.UUID;
 import java.util.logging.Logger;
 
 public class PlayerManager implements com.lishid.openinv.internal.PlayerManager {
 
-  private static boolean paper;
-
-  static {
-    try {
-      Class.forName("io.papermc.paper.configuration.Configuration");
-      paper = true;
-    } catch (ClassNotFoundException ignored) {
-      paper = false;
-    }
-  }
-
   private final @NotNull Logger logger;
   private @Nullable Field bukkitEntity;
 
@@ -158,39 +141,9 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
     // Game type settings are also loaded separately.
     player.loadGameTypes(loadedData);
 
-    if (paper) {
-      // Paper: world is not loaded by ServerPlayer#load(CompoundTag).
-      parseWorld(player, loadedData);
-    }
-
     return true;
   }
 
-  private void parseWorld(@NotNull ServerPlayer player, @NotNull CompoundTag loadedData) {
-    // See PlayerList#placeNewPlayer
-    World bukkitWorld;
-    if (loadedData.contains("WorldUUIDMost") && loadedData.contains("WorldUUIDLeast")) {
-      // Modern Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(new UUID(loadedData.getLong("WorldUUIDMost"), loadedData.getLong("WorldUUIDLeast")));
-    } else if (loadedData.contains("world", net.minecraft.nbt.Tag.TAG_STRING)) {
-      // Legacy Bukkit world.
-      bukkitWorld = Bukkit.getServer().getWorld(loadedData.getString("world"));
-    } else {
-      // Vanilla player data.
-      DimensionType.parseLegacy(new Dynamic<>(NbtOps.INSTANCE, loadedData.get("Dimension")))
-          .resultOrPartial(logger::warning)
-          .map(player.server::getLevel)
-          // If ServerLevel exists, set, otherwise move to spawn.
-          .ifPresentOrElse(player::setServerLevel, () -> player.spawnIn(null));
-      return;
-    }
-    if (bukkitWorld == null) {
-      player.spawnIn(null);
-      return;
-    }
-    player.setServerLevel(((CraftWorld) bukkitWorld).getHandle());
-  }
-
   private void injectPlayer(ServerPlayer player) throws IllegalAccessException {
     if (bukkitEntity == null) {
       return;
@@ -223,7 +176,7 @@ public class PlayerManager implements com.lishid.openinv.internal.PlayerManager
   public @Nullable InventoryView openInventory(@NotNull Player bukkitPlayer, @NotNull ISpecialInventory inventory, boolean viewOnly) {
     ServerPlayer player = getHandle(bukkitPlayer);
 
-    if (player.connection == null) {
+    if (!OpenPlayer.isConnected(player.connection)) {
       return null;
     }
 

internal/v1_21_R2/pom.xml

@@ -1,77 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!--
-  ~ Copyright (C) 2011-2023 lishid. All rights reserved.
-  ~
-  ~ This program is free software: you can redistribute it and/or modify
-  ~ it under the terms of the GNU General Public License as published by
-  ~ the Free Software Foundation, version 3.
-  ~
-  ~ This program is distributed in the hope that it will be useful,
-  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
-  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-  ~ GNU General Public License for more details.
-  ~
-  ~ You should have received a copy of the GNU General Public License
-  ~ along with this program. If not, see <http://www.gnu.org/licenses/>.
-  -->
-
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <parent>
-    <artifactId>openinvparent</artifactId>
-    <groupId>com.lishid</groupId>
-    <relativePath>../../pom.xml</relativePath>
-    <version>5.1.5</version>
-  </parent>
-
-  <artifactId>openinvadapter1_21_R2</artifactId>
-  <name>OpenInvAdapter1_21_R2</name>
-
-  <properties>
-    <maven.compiler.system>21</maven.compiler.system>
-    <maven.compiler.release>21</maven.compiler.release>
-    <spigot.version>1.21.3-R0.1-SNAPSHOT</spigot.version>
-  </properties>
-
-  <dependencies>
-    <dependency>
-      <groupId>org.spigotmc</groupId>
-      <artifactId>spigot-api</artifactId>
-      <version>${spigot.version}</version>
-    </dependency>
-    <dependency>
-      <artifactId>spigot</artifactId>
-      <groupId>org.spigotmc</groupId>
-      <scope>provided</scope>
-      <version>${spigot.version}</version>
-      <classifier>remapped-mojang</classifier>
-    </dependency>
-    <dependency>
-      <artifactId>openinvapi</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>openinvcommon</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>annotations</artifactId>
-      <groupId>org.jetbrains</groupId>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-      </plugin>
-      <plugin>
-        <groupId>net.md-5</groupId>
-        <artifactId>specialsource-maven-plugin</artifactId>
-      </plugin>
-    </plugins>
-  </build>
-
-</project>

internal/v1_21_R2/src/main/java/com/lishid/openinv/internal/v1_21_R2/container/OpenEnderChest.java

@@ -1,196 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R2.container;
-
-import com.lishid.openinv.internal.ISpecialEnderChest;
-import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R2.container.menu.OpenEnderChestMenu;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
-import net.minecraft.core.NonNullList;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.ContainerHelper;
-import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.entity.player.StackedItemContents;
-import net.minecraft.world.inventory.AbstractContainerMenu;
-import net.minecraft.world.inventory.StackedContentsCompatible;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
-import org.bukkit.entity.HumanEntity;
-import org.bukkit.event.inventory.InventoryType;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class OpenEnderChest implements Container, StackedContentsCompatible, InternalOwned<ServerPlayer>,
-    ISpecialEnderChest {
-
-  private CraftInventory inventory;
-  private @NotNull ServerPlayer owner;
-  private NonNullList<ItemStack> items;
-  private int maxStack = 64;
-  private final List<HumanEntity> transaction = new ArrayList<>();
-
-  public OpenEnderChest(@NotNull org.bukkit.entity.Player player) {
-    this.owner = PlayerManager.getHandle(player);
-    this.items = owner.getEnderChestInventory().items;
-  }
-
-  @Override
-  public @NotNull ServerPlayer getOwnerHandle() {
-    return owner;
-  }
-
-  @Override
-  public @NotNull org.bukkit.inventory.Inventory getBukkitInventory() {
-    if (inventory == null) {
-      inventory = new CraftInventory(this) {
-        @Override
-        public @NotNull InventoryType getType() {
-          return InventoryType.ENDER_CHEST;
-        }
-      };
-    }
-    return inventory;
-  }
-
-  @Override
-  public void setPlayerOnline(@NotNull org.bukkit.entity.Player player) {
-    owner = PlayerManager.getHandle(player);
-    NonNullList<ItemStack> activeItems = owner.getEnderChestInventory().items;
-
-    // Guard against size changing. Theoretically on Purpur all row variations still have 6 rows internally.
-    int max = Math.min(items.size(), activeItems.size());
-    for (int index = 0; index < max; ++index) {
-      activeItems.set(index, items.get(index));
-    }
-
-    items = activeItems;
-  }
-
-  @Override
-  public void setPlayerOffline() {}
-
-  @Override
-  public @NotNull org.bukkit.entity.Player getPlayer() {
-    return owner.getBukkitEntity();
-  }
-
-  @Override
-  public int getContainerSize() {
-    return items.size();
-  }
-
-  @Override
-  public boolean isEmpty() {
-    return items.stream().allMatch(ItemStack::isEmpty);
-  }
-
-  @Override
-  public ItemStack getItem(int index) {
-    return index >= 0 && index < items.size() ? items.get(index) : ItemStack.EMPTY;
-  }
-
-  @Override
-  public ItemStack removeItem(int index, int amount) {
-    ItemStack itemstack = ContainerHelper.removeItem(items, index, amount);
-
-    if (!itemstack.isEmpty()) {
-      setChanged();
-    }
-
-    return itemstack;
-  }
-
-  @Override
-  public ItemStack removeItemNoUpdate(int index) {
-    return index >= 0 && index < items.size() ? items.set(index, ItemStack.EMPTY) : ItemStack.EMPTY;
-  }
-
-  @Override
-  public void setItem(int index, ItemStack itemStack) {
-    if (index >= 0 && index < items.size()) {
-      items.set(index, itemStack);
-    }
-  }
-
-  @Override
-  public int getMaxStackSize() {
-    return maxStack;
-  }
-
-  @Override
-  public void setChanged() {
-    this.owner.getEnderChestInventory().setChanged();
-  }
-
-  @Override
-  public boolean stillValid(Player player) {
-    return true;
-  }
-
-  @Override
-  public List<ItemStack> getContents() {
-    return items;
-  }
-
-  @Override
-  public void onOpen(CraftHumanEntity craftHumanEntity) {
-    transaction.add(craftHumanEntity);
-  }
-
-  @Override
-  public void onClose(CraftHumanEntity craftHumanEntity) {
-    transaction.remove(craftHumanEntity);
-  }
-
-  @Override
-  public List<HumanEntity> getViewers() {
-    return transaction;
-  }
-
-  @Override
-  public org.bukkit.entity.Player getOwner() {
-    return getPlayer();
-  }
-
-  @Override
-  public void setMaxStackSize(int size) {
-    maxStack = size;
-  }
-
-  @Override
-  public @Nullable Location getLocation() {
-    return null;
-  }
-
-  @Override
-  public void clearContent() {
-    items.clear();
-    setChanged();
-  }
-
-  @Override
-  public void fillStackedContents(StackedItemContents stackedContents) {
-    for (ItemStack itemstack : items) {
-      stackedContents.accountStack(itemstack);
-    }
-  }
-
-  public Component getTitle() {
-    return Component.translatableWithFallback("openinv.container.enderchest.prefix", "", owner.getName())
-        .append(Component.translatable("container.enderchest"))
-        .append(Component.translatableWithFallback("openinv.container.enderchest.suffix", " - %s", owner.getName()));
-  }
-
-  public @Nullable AbstractContainerMenu createMenu(Player player, int i, boolean viewOnly) {
-    if (player instanceof ServerPlayer serverPlayer) {
-      return new OpenEnderChestMenu(this, serverPlayer, i, viewOnly);
-    }
-    return null;
-  }
-
-}

internal/v1_21_R2/src/main/java/com/lishid/openinv/internal/v1_21_R2/container/OpenInventory.java

@@ -1,364 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R2.container;
-
-import com.lishid.openinv.internal.ISpecialPlayerInventory;
-import com.lishid.openinv.internal.InternalOwned;
-import com.lishid.openinv.internal.v1_21_R2.container.bukkit.OpenPlayerInventory;
-import com.lishid.openinv.internal.v1_21_R2.container.menu.OpenInventoryMenu;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.Content;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentCrafting;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentCraftingResult;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentCursor;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentDrop;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentEquipment;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentList;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentOffHand;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.ContentViewOnly;
-import com.lishid.openinv.internal.v1_21_R2.container.slot.SlotViewOnly;
-import com.lishid.openinv.internal.v1_21_R2.player.PlayerManager;
-import net.minecraft.ChatFormatting;
-import net.minecraft.core.NonNullList;
-import net.minecraft.network.chat.Component;
-import net.minecraft.network.chat.MutableComponent;
-import net.minecraft.resources.ResourceLocation;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.entity.EquipmentSlot;
-import net.minecraft.world.entity.player.Inventory;
-import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.inventory.AbstractContainerMenu;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.Location;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftHumanEntity;
-import org.bukkit.craftbukkit.v1_21_R2.inventory.CraftInventory;
-import org.bukkit.entity.HumanEntity;
-import org.bukkit.event.inventory.InventoryType;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class OpenInventory implements Container, InternalOwned<ServerPlayer>, ISpecialPlayerInventory {
-
-  private final List<Content> slots;
-  private final int size;
-  private ServerPlayer owner;
-  private int maxStackSize = 99;
-  private CraftInventory bukkitEntity;
-  public List<HumanEntity> transaction = new ArrayList<>();
-
-  public OpenInventory(@NotNull org.bukkit.entity.Player bukkitPlayer) {
-    owner = PlayerManager.getHandle(bukkitPlayer);
-
-    // Get total size, rounding up to nearest 9 for client compatibility.
-    int rawSize = owner.getInventory().getContainerSize() + owner.inventoryMenu.getCraftSlots().getContainerSize() + 1;
-    size = ((int) Math.ceil(rawSize / 9.0)) * 9;
-
-    slots = NonNullList.withSize(size, new ContentViewOnly(owner));
-    setupSlots();
-  }
-
-  private void setupSlots() {
-    // Top of inventory: Regular contents.
-    int nextIndex = addMainInventory();
-
-    // If inventory is expected size, we can arrange slots to be pretty.
-    Inventory ownerInv = owner.getInventory();
-    if (ownerInv.items.size() == 36
-        && ownerInv.armor.size() == 4
-        && ownerInv.offhand.size() == 1
-        && owner.inventoryMenu.getCraftSlots().getContainerSize() == 4) {
-      // Armor slots: Bottom left.
-      addArmor(36);
-      // Off-hand: Below chestplate.
-      addOffHand(46);
-      // Drop slot: Bottom right.
-      slots.set(53, new ContentDrop(owner));
-      // Cursor slot: Above drop.
-      slots.set(44, new ContentCursor(owner));
-
-      // Crafting is displayed in the bottom right corner.
-      // As we're using the pretty view, this is a 3x2.
-      addCrafting(41, true);
-      return;
-    }
-
-    // Otherwise we'll just add elements linearly.
-    nextIndex = addArmor(nextIndex);
-    nextIndex = addOffHand(nextIndex);
-    nextIndex = addCrafting(nextIndex, false);
-    slots.set(nextIndex, new ContentCursor(owner));
-    // Drop slot last.
-    slots.set(slots.size() - 1, new ContentDrop(owner));
-  }
-
-  private int addMainInventory() {
-    int listSize = owner.getInventory().items.size();
-    // Hotbar slots are 0-8. We want those to appear on the bottom of the inventory like a normal player inventory,
-    // so everything else needs to move up a row.
-    int hotbarDiff = listSize - 9;
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      InventoryType.SlotType type;
-      int invIndex;
-      if (localIndex < hotbarDiff) {
-        invIndex = localIndex + 9;
-        type = InventoryType.SlotType.CONTAINER;
-      } else {
-        type = InventoryType.SlotType.QUICKBAR;
-        invIndex = localIndex - hotbarDiff;
-      }
-
-      slots.set(localIndex, new ContentList(owner, invIndex, type) {
-        @Override
-        public void setHolder(@NotNull ServerPlayer holder) {
-          items = holder.getInventory().items;
-        }
-      });
-    }
-    return listSize;
-  }
-
-  private int addArmor(int startIndex) {
-    int listSize = owner.getInventory().armor.size();
-
-    for (int i = 0; i < listSize; ++i) {
-      // Armor slots go bottom to top; boots are slot 0, helmet is slot 3.
-      // Since we have to display horizontally due to space restrictions,
-      // making the left side the "top" is more user-friendly.
-      int armorIndex;
-      EquipmentSlot slot;
-      switch (i) {
-        case 3 -> {
-          armorIndex = 0;
-          slot = EquipmentSlot.FEET;
-        }
-        case 2 -> {
-          armorIndex = 1;
-          slot = EquipmentSlot.LEGS;
-        }
-        case 1 -> {
-          armorIndex = 2;
-          slot = EquipmentSlot.CHEST;
-        }
-        case 0 -> {
-          armorIndex = 3;
-          slot = EquipmentSlot.HEAD;
-        }
-        default -> {
-          // In the event that new armor slots are added, they can be placed at the end.
-          armorIndex = i;
-          slot = EquipmentSlot.MAINHAND;
-        }
-      }
-
-      slots.set(startIndex + i, new ContentEquipment(owner, armorIndex, slot));
-    }
-
-    return startIndex + listSize;
-  }
-
-  private int addOffHand(int startIndex) {
-    int listSize = owner.getInventory().offhand.size();
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      slots.set(startIndex + localIndex, new ContentOffHand(owner, localIndex));
-    }
-    return startIndex + listSize;
-  }
-
-  private int addCrafting(int startIndex, boolean pretty) {
-    int listSize = owner.inventoryMenu.getCraftSlots().getContents().size();
-    pretty &= listSize == 4;
-
-    for (int localIndex = 0; localIndex < listSize; ++localIndex) {
-      // Pretty display is a 2x2 rather than linear.
-      // If index is in top row, grid is not 2x2, or pretty is disabled, just use current index.
-      // Otherwise, subtract 2 and add 9 to start in the same position on the next row.
-      int modIndex = startIndex + (localIndex < 2 || !pretty ? localIndex : localIndex + 7);
-
-      slots.set(modIndex, new ContentCrafting(owner, localIndex));
-    }
-
-    if (pretty) {
-      slots.set(startIndex + 2, new ContentViewOnly(owner) {
-        @Override
-        public Slot asSlot(Container container, int slot, int x, int y) {
-          return new SlotViewOnly(container, slot, x, y) {
-            @Override
-            public ItemStack getOrDefault() {
-              return Placeholders.craftingOutput;
-            }
-          };
-        }
-      });
-      slots.set(startIndex + 11, new ContentCraftingResult(owner));
-    }
-
-    return startIndex + listSize;
-  }
-
-  public Slot getMenuSlot(int index, int x, int y) {
-    return slots.get(index).asSlot(this, index, x, y);
-  }
-
-  public InventoryType.SlotType getSlotType(int index) {
-    return slots.get(index).getSlotType();
-  }
-
-  public @NotNull Component getTitle(@Nullable ServerPlayer viewer) {
-    MutableComponent component = Component.empty();
-    // Prefix for use with custom bitmap image fonts.
-    if (owner.equals(viewer)) {
-      component.append(
-          Component.translatableWithFallback("openinv.container.inventory.self", "")
-              .withStyle(style -> style
-                  .withFont(ResourceLocation.parse("openinv:font/inventory"))
-                  .withColor(ChatFormatting.WHITE)));
-    } else {
-      component.append(
-          Component.translatableWithFallback("openinv.container.inventory.other", "")
-              .withStyle(style -> style
-                  .withFont(ResourceLocation.parse("openinv:font/inventory"))
-                  .withColor(ChatFormatting.WHITE)));
-    }
-    // Normal title: "Inventory - OwnerName"
-    component.append(Component.translatableWithFallback("openinv.container.inventory.prefix", "", owner.getName()))
-        .append(Component.translatable("container.inventory"))
-        .append(Component.translatableWithFallback("openinv.container.inventory.suffix", " - %s", owner.getName()));
-    return component;
-  }
-
-  @Override
-  public ServerPlayer getOwnerHandle() {
-    return owner;
-  }
-
-  @Override
-  public @NotNull org.bukkit.inventory.Inventory getBukkitInventory() {
-    if (bukkitEntity == null) {
-      bukkitEntity = new OpenPlayerInventory(this);
-    }
-    return bukkitEntity;
-  }
-
-  @Override
-  public void setPlayerOnline(@NotNull org.bukkit.entity.Player player) {
-    ServerPlayer newOwner = PlayerManager.getHandle(player);
-    // Only transfer regular inventory - crafting and cursor slots are transient.
-    newOwner.getInventory().replaceWith(owner.getInventory());
-    owner = newOwner;
-    // Update slots to point to new inventory.
-    slots.forEach(slot -> slot.setHolder(newOwner));
-  }
-
-  @Override
-  public void setPlayerOffline() {}
-
-  @Override
-  public boolean isInUse() {
-    return !transaction.isEmpty();
-  }
-
-  @Override
-  public @NotNull org.bukkit.entity.Player getPlayer() {
-    return getOwner();
-  }
-
-  @Override
-  public int getContainerSize() {
-    return size;
-  }
-
-  @Override
-  public boolean isEmpty() {
-    return slots.stream().map(Content::get).allMatch(ItemStack::isEmpty);
-  }
-
-  @Override
-  public ItemStack getItem(int index) {
-    return slots.get(index).get();
-  }
-
-  @Override
-  public ItemStack removeItem(int index, int amount) {
-    return slots.get(index).removePartial(amount);
-  }
-
-  @Override
-  public ItemStack removeItemNoUpdate(int index) {
-    return slots.get(index).remove();
-  }
-
-  @Override
-  public void setItem(int index, ItemStack itemStack) {
-    slots.get(index).set(itemStack);
-  }
-
-  @Override
-  public int getMaxStackSize() {
-    return maxStackSize;
-  }
-
-  @Override
-  public void setMaxStackSize(int maxStackSize) {
-    this.maxStackSize = maxStackSize;
-  }
-
-  @Override
-  public void setChanged() {}
-
-  @Override
-  public boolean stillValid(Player player) {
-    return true;
-  }
-
-  @Override
-  public List<ItemStack> getContents() {
-    NonNullList<ItemStack> contents = NonNullList.withSize(getContainerSize(), ItemStack.EMPTY);
-    for (int i = 0; i < getContainerSize(); ++i) {
-      contents.set(i, getItem(i));
-    }
-    return contents;
-  }
-
-  @Override
-  public void onOpen(CraftHumanEntity viewer) {
-    transaction.add(viewer);
-  }
-
-  @Override
-  public void onClose(CraftHumanEntity viewer) {
-    transaction.remove(viewer);
-  }
-
-  @Override
-  public List<HumanEntity> getViewers() {
-    return transaction;
-  }
-
-  @Override
-  public org.bukkit.entity.Player getOwner() {
-    return owner.getBukkitEntity();
-  }
-
-  @Override
-  public Location getLocation() {
-    return owner.getBukkitEntity().getLocation();
-  }
-
-  @Override
-  public void clearContent() {
-    owner.getInventory().clearContent();
-    owner.inventoryMenu.getCraftSlots().clearContent();
-    owner.inventoryMenu.slotsChanged(owner.inventoryMenu.getCraftSlots());
-    owner.containerMenu.setCarried(ItemStack.EMPTY);
-  }
-
-  public @Nullable AbstractContainerMenu createMenu(Player player, int i, boolean viewOnly) {
-    if (player instanceof ServerPlayer serverPlayer) {
-      return new OpenInventoryMenu(this, serverPlayer, i, viewOnly);
-    }
-    return null;
-  }
-
-}

internal/v1_21_R2/src/main/java/com/lishid/openinv/internal/v1_21_R2/container/slot/ContentList.java

@@ -1,58 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R2.container.slot;
-
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.ContainerHelper;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.event.inventory.InventoryType;
-
-import java.util.List;
-
-/**
- * A normal slot backed by an item list.
- */
-public abstract class ContentList implements Content {
-
-  private final int index;
-  private final InventoryType.SlotType slotType;
-  protected List<ItemStack> items;
-
-  public ContentList(ServerPlayer holder, int index, InventoryType.SlotType slotType) {
-    this.index = index;
-    this.slotType = slotType;
-    setHolder(holder);
-  }
-
-  @Override
-  public ItemStack get() {
-    return items.get(index);
-  }
-
-  @Override
-  public ItemStack remove() {
-    ItemStack removed = items.remove(index);
-    return removed == null || removed.isEmpty() ? ItemStack.EMPTY : removed;
-  }
-
-  @Override
-  public ItemStack removePartial(int amount) {
-    return ContainerHelper.removeItem(items, index, amount);
-  }
-
-  @Override
-  public void set(ItemStack itemStack) {
-    items.set(index, itemStack);
-  }
-
-  @Override
-  public Slot asSlot(Container container, int slot, int x, int y) {
-    return new Slot(container, slot, x, y);
-  }
-
-  @Override
-  public InventoryType.SlotType getSlotType() {
-    return slotType;
-  }
-
-}

internal/v1_21_R2/src/main/java/com/lishid/openinv/internal/v1_21_R2/player/OpenPlayer.java

@@ -1,178 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R2.player;
-
-import com.lishid.openinv.event.OpenEvents;
-import com.mojang.logging.LogUtils;
-import net.minecraft.Util;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.NbtIo;
-import net.minecraft.nbt.NumericTag;
-import net.minecraft.nbt.Tag;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.level.storage.PlayerDataStorage;
-import org.bukkit.craftbukkit.v1_21_R2.CraftServer;
-import org.bukkit.craftbukkit.v1_21_R2.entity.CraftPlayer;
-import org.jetbrains.annotations.Contract;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.Set;
-
-public class OpenPlayer extends CraftPlayer {
-
-  /**
-   * List of tags to always reset when saving.
-   *
-   * @see net.minecraft.world.entity.Entity#saveWithoutId(CompoundTag)
-   * @see net.minecraft.server.level.ServerPlayer#addAdditionalSaveData(CompoundTag)
-   * @see net.minecraft.world.entity.player.Player#addAdditionalSaveData(CompoundTag)
-   * @see net.minecraft.world.entity.LivingEntity#addAdditionalSaveData(CompoundTag)
-   */
-  private static final Set<String> RESET_TAGS = Set.of(
-      // Entity#saveWithoutId(CompoundTag)
-      "CustomName",
-      "CustomNameVisible",
-      "Silent",
-      "NoGravity",
-      "Glowing",
-      "TicksFrozen",
-      "HasVisualFire",
-      "Tags",
-      "Passengers",
-      // ServerPlayer#addAdditionalSaveData(CompoundTag)
-      // Intentional omissions to prevent mount loss: Attach, Entity, and RootVehicle
-      "warden_spawn_tracker",
-      "enteredNetherPosition",
-      "SpawnX",
-      "SpawnY",
-      "SpawnZ",
-      "SpawnForced",
-      "SpawnAngle",
-      "SpawnDimension",
-      "raid_omen_position",
-      "ender_pearls",
-      // Player#addAdditionalSaveData(CompoundTag)
-      "ShoulderEntityLeft",
-      "ShoulderEntityRight",
-      "LastDeathLocation",
-      "current_explosion_impact_pos",
-      // LivingEntity#addAdditionalSaveData(CompoundTag)
-      "active_effects",
-      "SleepingX",
-      "SleepingY",
-      "SleepingZ",
-      "Brain"
-  );
-
-  private final PlayerManager manager;
-
-  OpenPlayer(CraftServer server, ServerPlayer entity, PlayerManager manager) {
-    super(server, entity);
-    this.manager = manager;
-  }
-
-  @Override
-  public void loadData() {
-    manager.loadData(getHandle());
-  }
-
-  @Override
-  public void saveData() {
-    if (OpenEvents.saveCancelled(this)) {
-      return;
-    }
-
-    ServerPlayer player = this.getHandle();
-    // See net.minecraft.world.level.storage.PlayerDataStorage#save(EntityHuman)
-    try {
-      PlayerDataStorage worldNBTStorage = player.server.getPlayerList().playerIo;
-
-      CompoundTag oldData = isOnline() ? null : worldNBTStorage.load(player.getName().getString(), player.getStringUUID()).orElse(null);
-      CompoundTag playerData = getWritableTag(oldData);
-      playerData = player.saveWithoutId(playerData);
-      setExtraData(playerData);
-
-      if (oldData != null) {
-        // Revert certain special data values when offline.
-        revertSpecialValues(playerData, oldData);
-      }
-
-      Path playerDataDir = worldNBTStorage.getPlayerDir().toPath();
-      Path tempFile = Files.createTempFile(playerDataDir, player.getStringUUID() + "-", ".dat");
-      NbtIo.writeCompressed(playerData, tempFile);
-      Path dataFile = playerDataDir.resolve(player.getStringUUID() + ".dat");
-      Path backupFile = playerDataDir.resolve(player.getStringUUID() + ".dat_old");
-      Util.safeReplaceFile(dataFile, tempFile, backupFile);
-    } catch (Exception e) {
-      LogUtils.getLogger().warn("Failed to save player data for {}: {}", player.getScoreboardName(), e);
-    }
-  }
-
-  @Contract("null -> new")
-  private @NotNull CompoundTag getWritableTag(@Nullable CompoundTag oldData) {
-    if (oldData == null) {
-      return new CompoundTag();
-    }
-
-    // Copy old data. This is a deep clone, so operating on it should be safe.
-    oldData = oldData.copy();
-
-    // Remove vanilla/server data that is not written every time.
-    oldData.getAllKeys()
-        .removeIf(key -> RESET_TAGS.contains(key) || key.startsWith("Bukkit"));
-
-    return oldData;
-  }
-
-  private void revertSpecialValues(@NotNull CompoundTag newData, @NotNull CompoundTag oldData) {
-    // Revert automatic updates to play timestamps.
-    copyValue(oldData, newData, "bukkit", "lastPlayed", NumericTag.class);
-    copyValue(oldData, newData, "Paper", "LastSeen", NumericTag.class);
-    copyValue(oldData, newData, "Paper", "LastLogin", NumericTag.class);
-  }
-
-  private <T extends Tag> void copyValue(
-      @NotNull CompoundTag source,
-      @NotNull CompoundTag target,
-      @NotNull String container,
-      @NotNull String key,
-      @SuppressWarnings("SameParameterValue") @NotNull Class<T> tagType) {
-    CompoundTag oldContainer = getTag(source, container, CompoundTag.class);
-    CompoundTag newContainer = getTag(target, container, CompoundTag.class);
-
-    // New container being null means the server implementation doesn't store this data.
-    if (newContainer == null) {
-      return;
-    }
-
-    // If old tag exists, copy it to new location, removing otherwise.
-    setTag(newContainer, key, getTag(oldContainer, key, tagType));
-  }
-
-  private <T extends Tag> @Nullable T getTag(
-      @Nullable CompoundTag container,
-      @NotNull String key,
-      @NotNull Class<T> dataType) {
-    if (container == null) {
-      return null;
-    }
-    Tag value = container.get(key);
-    if (value == null || !dataType.isAssignableFrom(value.getClass())) {
-      return null;
-    }
-    return dataType.cast(value);
-  }
-
-  private <T extends Tag> void setTag(
-      @NotNull CompoundTag container,
-      @NotNull String key,
-      @Nullable T data) {
-    if (data == null) {
-      container.remove(key);
-    } else {
-      container.put(key, data);
-    }
-  }
-
-}

internal/v1_21_R3/pom.xml

@@ -1,77 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!--
-  ~ Copyright (C) 2011-2023 lishid. All rights reserved.
-  ~
-  ~ This program is free software: you can redistribute it and/or modify
-  ~ it under the terms of the GNU General Public License as published by
-  ~ the Free Software Foundation, version 3.
-  ~
-  ~ This program is distributed in the hope that it will be useful,
-  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
-  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-  ~ GNU General Public License for more details.
-  ~
-  ~ You should have received a copy of the GNU General Public License
-  ~ along with this program. If not, see <http://www.gnu.org/licenses/>.
-  -->
-
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-  <modelVersion>4.0.0</modelVersion>
-
-  <parent>
-    <artifactId>openinvparent</artifactId>
-    <groupId>com.lishid</groupId>
-    <relativePath>../../pom.xml</relativePath>
-    <version>5.1.5</version>
-  </parent>
-
-  <artifactId>openinvadapter1_21_R3</artifactId>
-  <name>OpenInvAdapter1_21_R3</name>
-
-  <properties>
-    <maven.compiler.system>21</maven.compiler.system>
-    <maven.compiler.release>21</maven.compiler.release>
-    <spigot.version>1.21.4-R0.1-SNAPSHOT</spigot.version>
-  </properties>
-
-  <dependencies>
-    <dependency>
-      <groupId>org.spigotmc</groupId>
-      <artifactId>spigot-api</artifactId>
-      <version>${spigot.version}</version>
-    </dependency>
-    <dependency>
-      <artifactId>spigot</artifactId>
-      <groupId>org.spigotmc</groupId>
-      <scope>provided</scope>
-      <version>${spigot.version}</version>
-      <classifier>remapped-mojang</classifier>
-    </dependency>
-    <dependency>
-      <artifactId>openinvapi</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>openinvcommon</artifactId>
-      <groupId>com.lishid</groupId>
-    </dependency>
-    <dependency>
-      <artifactId>annotations</artifactId>
-      <groupId>org.jetbrains</groupId>
-    </dependency>
-  </dependencies>
-
-  <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-      </plugin>
-      <plugin>
-        <groupId>net.md-5</groupId>
-        <artifactId>specialsource-maven-plugin</artifactId>
-      </plugin>
-    </plugins>
-  </build>
-
-</project>

internal/v1_21_R3/src/main/java/com/lishid/openinv/internal/v1_21_R3/container/AnySilentContainer.java

@@ -1,210 +0,0 @@
-/*
- * Copyright (C) 2011-2023 lishid. All rights reserved.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-package com.lishid.openinv.internal.v1_21_R3.container;
-
-import com.lishid.openinv.internal.AnySilentContainerBase;
-import com.lishid.openinv.internal.v1_21_R3.container.menu.OpenChestMenu;
-import com.lishid.openinv.internal.v1_21_R3.player.PlayerManager;
-import com.lishid.openinv.util.ReflectionHelper;
-import com.lishid.openinv.util.lang.LanguageManager;
-import net.minecraft.core.BlockPos;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.server.level.ServerPlayerGameMode;
-import net.minecraft.world.MenuProvider;
-import net.minecraft.world.SimpleMenuProvider;
-import net.minecraft.world.inventory.ChestMenu;
-import net.minecraft.world.inventory.MenuType;
-import net.minecraft.world.inventory.PlayerEnderChestContainer;
-import net.minecraft.world.level.GameType;
-import net.minecraft.world.level.block.BarrelBlock;
-import net.minecraft.world.level.block.Block;
-import net.minecraft.world.level.block.ChestBlock;
-import net.minecraft.world.level.block.ShulkerBoxBlock;
-import net.minecraft.world.level.block.TrappedChestBlock;
-import net.minecraft.world.level.block.entity.BlockEntity;
-import net.minecraft.world.level.block.entity.EnderChestBlockEntity;
-import net.minecraft.world.level.block.entity.RandomizableContainerBlockEntity;
-import net.minecraft.world.level.block.state.BlockState;
-import org.bukkit.GameMode;
-import org.bukkit.Material;
-import org.bukkit.Statistic;
-import org.bukkit.entity.Player;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.lang.reflect.Field;
-import java.util.logging.Logger;
-
-public class AnySilentContainer extends AnySilentContainerBase {
-
-    private final @NotNull Logger logger;
-    private final @NotNull LanguageManager lang;
-    private @Nullable Field serverPlayerGameModeGameType;
-
-    public AnySilentContainer(@NotNull Logger logger, @NotNull LanguageManager lang) {
-        this.logger = logger;
-        this.lang = lang;
-        try {
-            try {
-                this.serverPlayerGameModeGameType = ServerPlayerGameMode.class.getDeclaredField("b");
-                this.serverPlayerGameModeGameType.setAccessible(true);
-            } catch (NoSuchFieldException e) {
-                logger.warning("ServerPlayerGameMode#gameModeForPlayer's obfuscated name has changed!");
-                logger.warning("Please report this at https://github.com/Jikoo/OpenInv/issues");
-                logger.warning("Attempting to fall through using reflection. Please verify that SilentContainer does not fail.");
-                // N.B. gameModeForPlayer is (for now) declared before previousGameModeForPlayer so silent shouldn't break.
-                this.serverPlayerGameModeGameType = ReflectionHelper.grabFieldByType(ServerPlayerGameMode.class, GameType.class);
-            }
-        } catch (SecurityException e) {
-            logger.warning("Unable to directly write player game mode! SilentContainer will fail.");
-            logger.log(java.util.logging.Level.WARNING, "Error obtaining GameType field", e);
-        }
-    }
-
-    @Override
-    public boolean activateContainer(
-            @NotNull final Player bukkitPlayer,
-            final boolean silentchest,
-            @NotNull final org.bukkit.block.Block bukkitBlock) {
-
-        // Silent ender chest is API-only
-        if (silentchest && bukkitBlock.getType() == Material.ENDER_CHEST) {
-            bukkitPlayer.openInventory(bukkitPlayer.getEnderChest());
-            bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
-            return true;
-        }
-
-        ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
-
-        final net.minecraft.world.level.Level level = player.level();
-        final BlockPos blockPos = new BlockPos(bukkitBlock.getX(), bukkitBlock.getY(), bukkitBlock.getZ());
-        final BlockEntity blockEntity = level.getBlockEntity(blockPos);
-
-        if (blockEntity == null) {
-            return false;
-        }
-
-        if (blockEntity instanceof EnderChestBlockEntity enderChestTile) {
-            // Anychest ender chest. See net.minecraft.world.level.block.EnderChestBlock
-            PlayerEnderChestContainer enderChest = player.getEnderChestInventory();
-            enderChest.setActiveChest(enderChestTile);
-            player.openMenu(new SimpleMenuProvider((containerCounter, playerInventory, ignored) -> {
-                MenuType<?> containers = OpenChestMenu.getChestMenuType(enderChest.getContainerSize());
-                int rows = enderChest.getContainerSize() / 9;
-                return new ChestMenu(containers, containerCounter, playerInventory, enderChest, rows);
-            }, Component.translatable("container.enderchest")));
-            bukkitPlayer.incrementStatistic(Statistic.ENDERCHEST_OPENED);
-            return true;
-        }
-
-        if (!(blockEntity instanceof MenuProvider menuProvider)) {
-            return false;
-        }
-
-        BlockState blockState = level.getBlockState(blockPos);
-        Block block = blockState.getBlock();
-
-        if (block instanceof ChestBlock chestBlock) {
-
-            // boolean flag: do not check if chest is blocked
-            menuProvider = chestBlock.getMenuProvider(blockState, level, blockPos, true);
-
-            if (menuProvider == null) {
-                lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
-                return false;
-            }
-
-            if (block instanceof TrappedChestBlock) {
-                bukkitPlayer.incrementStatistic(Statistic.TRAPPED_CHEST_TRIGGERED);
-            } else {
-                bukkitPlayer.incrementStatistic(Statistic.CHEST_OPENED);
-            }
-        }
-
-        if (block instanceof ShulkerBoxBlock) {
-            bukkitPlayer.incrementStatistic(Statistic.SHULKER_BOX_OPENED);
-        }
-
-        if (block instanceof BarrelBlock) {
-            bukkitPlayer.incrementStatistic(Statistic.OPEN_BARREL);
-        }
-
-        // AnyChest only - SilentChest not active, container unsupported, or unnecessary.
-        if (!silentchest || player.gameMode.getGameModeForPlayer() == GameType.SPECTATOR) {
-            player.openMenu(menuProvider);
-            return true;
-        }
-
-        // SilentChest requires access to setting players' game mode directly.
-        if (this.serverPlayerGameModeGameType == null) {
-            return false;
-        }
-
-        if (blockEntity instanceof RandomizableContainerBlockEntity lootable) {
-            if (lootable.lootTable != null) {
-                lang.sendSystemMessage(bukkitPlayer, "messages.error.lootNotGenerated");
-                return false;
-            }
-        }
-
-        GameType gameType = player.gameMode.getGameModeForPlayer();
-        this.forceGameType(player, GameType.SPECTATOR);
-        player.openMenu(menuProvider);
-        this.forceGameType(player, gameType);
-        return true;
-    }
-
-    @Override
-    public void deactivateContainer(@NotNull final Player bukkitPlayer) {
-        if (this.serverPlayerGameModeGameType == null || bukkitPlayer.getGameMode() == GameMode.SPECTATOR) {
-            return;
-        }
-
-        ServerPlayer player = PlayerManager.getHandle(bukkitPlayer);
-
-        // Force game mode change without informing plugins or players.
-        // Regular game mode set calls GameModeChangeEvent and is cancellable.
-        GameType gameType = player.gameMode.getGameModeForPlayer();
-        this.forceGameType(player, GameType.SPECTATOR);
-
-        // ServerPlayer#closeContainer cannot be called without entering an
-        // infinite loop because this method is called during inventory close.
-        // From ServerPlayer#closeContainer -> CraftEventFactory#handleInventoryCloseEvent
-        player.containerMenu.transferTo(player.inventoryMenu, player.getBukkitEntity());
-        // From ServerPlayer#closeContainer
-        player.doCloseContainer();
-        // Regular inventory close will handle the rest - packet sending, etc.
-
-        // Revert forced game mode.
-        this.forceGameType(player, gameType);
-    }
-
-    private void forceGameType(final ServerPlayer player, final GameType gameMode) {
-        if (this.serverPlayerGameModeGameType == null) {
-            // No need to warn repeatedly, error on startup and lack of function should be enough.
-            return;
-        }
-        try {
-            this.serverPlayerGameModeGameType.setAccessible(true);
-            this.serverPlayerGameModeGameType.set(player.gameMode, gameMode);
-        } catch (IllegalArgumentException | IllegalAccessException e) {
-            logger.log(java.util.logging.Level.WARNING, "Error bypassing GameModeChangeEvent", e);
-        }
-    }
-
-}

internal/v1_21_R3/src/main/java/com/lishid/openinv/internal/v1_21_R3/container/Placeholders.java

@@ -1,183 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R3.container;
-
-import net.minecraft.core.Registry;
-import net.minecraft.core.RegistryAccess;
-import net.minecraft.core.component.DataComponents;
-import net.minecraft.core.registries.Registries;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.nbt.TagParser;
-import net.minecraft.network.chat.Component;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.util.Unit;
-import net.minecraft.world.item.DyeColor;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.Items;
-import net.minecraft.world.item.component.CustomModelData;
-import net.minecraft.world.item.component.DyedItemColor;
-import net.minecraft.world.level.GameType;
-import net.minecraft.world.level.ItemLike;
-import net.minecraft.world.level.block.entity.BannerPattern;
-import net.minecraft.world.level.block.entity.BannerPatternLayers;
-import net.minecraft.world.level.block.entity.BannerPatterns;
-import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.craftbukkit.v1_21_R3.CraftRegistry;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.EnumMap;
-import java.util.List;
-import java.util.Optional;
-
-public final class Placeholders {
-
-  private static final CustomModelData DEFAULT_CUSTOM_MODEL_DATA = new CustomModelData(List.of(), List.of(), List.of("openinv:custom"), List.of());
-  public static final @NotNull EnumMap<GameType, ItemStack> BLOCKED_GAME_TYPE = new EnumMap<>(GameType.class);
-  public static @NotNull ItemStack craftingOutput = defaultCraftingOutput();
-  public static @NotNull ItemStack cursor = defaultCursor();
-  public static @NotNull ItemStack drop = defaultDrop();
-  public static @NotNull ItemStack emptyHelmet = getEmptyArmor(Items.LEATHER_HELMET);
-  public static @NotNull ItemStack emptyChestplate = getEmptyArmor(Items.LEATHER_CHESTPLATE);
-  public static @NotNull ItemStack emptyLeggings = getEmptyArmor(Items.LEATHER_LEGGINGS);
-  public static @NotNull ItemStack emptyBoots = getEmptyArmor(Items.LEATHER_BOOTS);
-  public static @NotNull ItemStack emptyOffHand = getEmptyShield();
-  public static @NotNull ItemStack notSlot = defaultNotSlot();
-  public static @NotNull ItemStack blockedOffline = defaultBlockedOffline();
-
-  static {
-    for (GameType type : GameType.values()) {
-      // Barrier: "Not available - Creative" etc.
-      ItemStack typeItem = new ItemStack(Items.BARRIER);
-      typeItem.set(
-          DataComponents.ITEM_NAME,
-          Component.translatable("options.narrator.notavailable").append(" - ").append(type.getShortDisplayName()));
-      BLOCKED_GAME_TYPE.put(type, typeItem);
-    }
-  }
-
-  public static void load(@NotNull ConfigurationSection section) throws Exception {
-    craftingOutput = parse(section, "crafting-output", craftingOutput);
-    cursor = parse(section, "cursor", cursor);
-    drop = parse(section, "drop", drop);
-    emptyHelmet = parse(section, "empty-helmet", emptyHelmet);
-    emptyChestplate = parse(section, "empty-chestplate", emptyChestplate);
-    emptyLeggings = parse(section, "empty-leggings", emptyLeggings);
-    emptyBoots = parse(section, "empty-boots", emptyBoots);
-    emptyOffHand = parse(section, "empty-off-hand", emptyOffHand);
-    notSlot = parse(section, "not-a-slot", notSlot);
-    blockedOffline = parse(section, "blocked.offline", blockedOffline);
-    BLOCKED_GAME_TYPE.put(GameType.CREATIVE, parse(section, "blocked.creative", BLOCKED_GAME_TYPE.get(GameType.CREATIVE)));
-    BLOCKED_GAME_TYPE.put(GameType.SPECTATOR, parse(section, "blocked.spectator", BLOCKED_GAME_TYPE.get(GameType.SPECTATOR)));
-  }
-
-  private static @NotNull ItemStack parse(
-      @NotNull ConfigurationSection section,
-      @NotNull String path,
-      @NotNull ItemStack defaultStack) throws Exception {
-    String itemText = section.getString(path);
-
-    if (itemText == null) {
-      return defaultStack;
-    }
-
-    CompoundTag compoundTag = TagParser.parseTag(itemText);
-    Optional<ItemStack> parsed = ItemStack.parse(CraftRegistry.getMinecraftRegistry(), compoundTag);
-    return parsed.filter(itemStack -> !itemStack.isEmpty()).orElse(defaultStack);
-  }
-
-  public static ItemStack survivalOnly(@NotNull ServerPlayer serverPlayer) {
-    if (serverPlayer.connection == null || serverPlayer.connection.isDisconnected()) {
-      return blockedOffline;
-    }
-
-    return BLOCKED_GAME_TYPE.getOrDefault(serverPlayer.gameMode.getGameModeForPlayer(), ItemStack.EMPTY);
-  }
-
-  private static ItemStack defaultCraftingOutput() {
-    // Crafting table: "Crafting"
-    ItemStack itemStack = new ItemStack(Items.CRAFTING_TABLE);
-    itemStack.set(DataComponents.ITEM_NAME, Component.translatable("container.crafting"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack defaultCursor() {
-    // Cursor-like banner with no tooltip
-    ItemStack itemStack = new ItemStack(Items.WHITE_BANNER);
-    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
-    Registry<BannerPattern> bannerPatterns = minecraftRegistry.lookupOrThrow(Registries.BANNER_PATTERN);
-    BannerPattern halfDiagBottomRight = bannerPatterns.getOrThrow(BannerPatterns.DIAGONAL_RIGHT).value();
-    BannerPattern downRight = bannerPatterns.getOrThrow(BannerPatterns.STRIPE_DOWNRIGHT).value();
-    BannerPattern border = bannerPatterns.getOrThrow(BannerPatterns.BORDER).value();
-    itemStack.set(DataComponents.BANNER_PATTERNS,
-        new BannerPatternLayers(List.of(
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfDiagBottomRight), DyeColor.GRAY),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(downRight), DyeColor.WHITE),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(border), DyeColor.GRAY))));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    return itemStack;
-  }
-
-  private static ItemStack defaultDrop() {
-    // Dropper: "Drop Selected Item"
-    ItemStack itemStack = new ItemStack(Items.DROPPER);
-    // Note: translatable component, not keybind component! We want the text identifying the keybind, not the key.
-    itemStack.set(DataComponents.ITEM_NAME, Component.translatable("key.drop"));
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack getEmptyArmor(ItemLike item) {
-    // Inventory-background-grey-ish leather armor with no tooltip
-    ItemStack itemStack = new ItemStack(item);
-    DyedItemColor color = new DyedItemColor(0xC8C8C8, false);
-    itemStack.set(DataComponents.DYED_COLOR, color);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack getEmptyShield() {
-    ItemStack itemStack = new ItemStack(Items.SHIELD);
-    itemStack.set(DataComponents.BASE_COLOR, DyeColor.MAGENTA);
-    RegistryAccess minecraftRegistry = CraftRegistry.getMinecraftRegistry();
-    Registry<BannerPattern> bannerPatterns = minecraftRegistry.lookupOrThrow(Registries.BANNER_PATTERN);
-    BannerPattern halfLeft = bannerPatterns.getOrThrow(BannerPatterns.HALF_VERTICAL).value();
-    BannerPattern topLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_LEFT).value();
-    BannerPattern topRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_TOP_RIGHT).value();
-    BannerPattern bottomLeft = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_LEFT).value();
-    BannerPattern bottomRight = bannerPatterns.getOrThrow(BannerPatterns.SQUARE_BOTTOM_RIGHT).value();
-    itemStack.set(DataComponents.BANNER_PATTERNS,
-        new BannerPatternLayers(List.of(
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(halfLeft), DyeColor.BLACK),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topLeft), DyeColor.MAGENTA),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomLeft), DyeColor.MAGENTA),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(topRight), DyeColor.BLACK),
-            new BannerPatternLayers.Layer(bannerPatterns.wrapAsHolder(bottomRight), DyeColor.BLACK))));
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack defaultNotSlot() {
-    // White pane with no tooltip
-    ItemStack itemStack = new ItemStack(Items.WHITE_STAINED_GLASS_PANE);
-    itemStack.set(DataComponents.HIDE_TOOLTIP, Unit.INSTANCE);
-    itemStack.set(DataComponents.CUSTOM_MODEL_DATA, DEFAULT_CUSTOM_MODEL_DATA);
-    return itemStack;
-  }
-
-  private static ItemStack defaultBlockedOffline() {
-    // Barrier: "Not available - Offline"
-    ItemStack itemStack = new ItemStack(Items.BARRIER);
-    itemStack.set(DataComponents.ITEM_NAME,
-        Component.translatable("options.narrator.notavailable")
-            .append(Component.literal(" - "))
-            .append(Component.translatable("gui.socialInteractions.status_offline")));
-    return itemStack;
-  }
-
-  private Placeholders() {
-    throw new IllegalStateException("Cannot create instance of utility class.");
-  }
-
-}

internal/v1_21_R3/src/main/java/com/lishid/openinv/internal/v1_21_R3/container/bukkit/OpenDummyInventory.java

@@ -1,172 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R3.container.bukkit;
-
-import com.lishid.openinv.internal.ViewOnly;
-import net.minecraft.world.Container;
-import org.bukkit.Material;
-import org.bukkit.craftbukkit.v1_21_R3.inventory.CraftInventory;
-import org.bukkit.event.inventory.InventoryType;
-import org.bukkit.inventory.ItemStack;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.ListIterator;
-
-/**
- * A locked down "empty" inventory that rejects plugin interaction.
- */
-public class OpenDummyInventory extends CraftInventory implements ViewOnly {
-
-  private final InventoryType type;
-
-  public OpenDummyInventory(Container inventory, InventoryType type) {
-    super(inventory);
-    this.type = type;
-  }
-
-  @Override
-  public @NotNull InventoryType getType() {
-    return type;
-  }
-
-  @Override
-  public @Nullable ItemStack getItem(int index) {
-    return null;
-  }
-
-  @Override
-  public void setItem(int index, @Nullable ItemStack item) {
-
-  }
-
-  @SuppressWarnings("NonApiType")
-  @Override
-  public @NotNull HashMap<Integer, ItemStack> addItem(@NotNull ItemStack... items) throws IllegalArgumentException {
-    return arrayToHashMap(items);
-  }
-
-  @SuppressWarnings("NonApiType")
-  @Override
-  public @NotNull HashMap<Integer, ItemStack> removeItem(@NotNull ItemStack... items) throws IllegalArgumentException {
-    return arrayToHashMap(items);
-  }
-
-  @SuppressWarnings("NonApiType")
-  private static @NotNull HashMap<Integer, ItemStack> arrayToHashMap(@NotNull ItemStack[] items) {
-    HashMap<Integer, ItemStack> ignored = new HashMap<>();
-    for (int index = 0; index < items.length; ++index) {
-      ignored.put(index, items[index]);
-    }
-    return ignored;
-  }
-
-  @Override
-  public ItemStack[] getContents() {
-    return new ItemStack[getSize()];
-  }
-
-  @Override
-  public void setContents(@NotNull ItemStack[] items) throws IllegalArgumentException {
-
-  }
-
-  @Override
-  public @NotNull ItemStack[] getStorageContents() {
-    return new ItemStack[getSize()];
-  }
-
-  @Override
-  public void setStorageContents(@NotNull ItemStack[] items) throws IllegalArgumentException {
-
-  }
-
-  @Override
-  public boolean contains(@NotNull Material material) throws IllegalArgumentException {
-    return false;
-  }
-
-  @Override
-  public boolean contains(@Nullable ItemStack item) {
-    return false;
-  }
-
-  @Override
-  public boolean contains(@NotNull Material material, int amount) throws IllegalArgumentException {
-    return false;
-  }
-
-  @Override
-  public boolean contains(@Nullable ItemStack item, int amount) {
-    return false;
-  }
-
-  @Override
-  public boolean containsAtLeast(@Nullable ItemStack item, int amount) {
-    return false;
-  }
-
-  @SuppressWarnings("NonApiType")
-  @Override
-  public @NotNull HashMap<Integer, ItemStack> all(
-      @NotNull Material material) throws IllegalArgumentException {
-    return new HashMap<>();
-  }
-
-  @SuppressWarnings("NonApiType")
-  @Override
-  public @NotNull HashMap<Integer, ItemStack> all(@Nullable ItemStack item) {
-    return new HashMap<>();
-  }
-
-  @Override
-  public int first(@NotNull Material material) throws IllegalArgumentException {
-    return -1;
-  }
-
-  @Override
-  public int first(@NotNull ItemStack item) {
-    return -1;
-  }
-
-  @Override
-  public int firstEmpty() {
-    return -1;
-  }
-
-  @Override
-  public boolean isEmpty() {
-    return true;
-  }
-
-  @Override
-  public void remove(@NotNull Material material) throws IllegalArgumentException {
-
-  }
-
-  @Override
-  public void remove(@NotNull ItemStack item) {
-
-  }
-
-  @Override
-  public void clear(int index) {
-
-  }
-
-  @Override
-  public void clear() {
-
-  }
-
-  @Override
-  public @NotNull ListIterator<ItemStack> iterator() {
-    return Collections.emptyListIterator();
-  }
-
-  @Override
-  public @NotNull ListIterator<ItemStack> iterator(int index) {
-    return Collections.emptyListIterator();
-  }
-
-}

internal/v1_21_R3/src/main/java/com/lishid/openinv/internal/v1_21_R3/container/bukkit/OpenDummyPlayerInventory.java

@@ -1,134 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R3.container.bukkit;
-
-import net.minecraft.world.Container;
-import org.bukkit.Material;
-import org.bukkit.entity.HumanEntity;
-import org.bukkit.event.inventory.InventoryType;
-import org.bukkit.inventory.EquipmentSlot;
-import org.bukkit.inventory.ItemStack;
-import org.bukkit.inventory.PlayerInventory;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-public class OpenDummyPlayerInventory extends OpenDummyInventory implements PlayerInventory {
-
-  public OpenDummyPlayerInventory(Container inventory) {
-    super(inventory, InventoryType.PLAYER);
-  }
-
-  @Override
-  public HumanEntity getHolder() {
-    return (HumanEntity) super.getHolder();
-  }
-
-  @Override
-  public @NotNull ItemStack[] getArmorContents() {
-    return new ItemStack[4];
-  }
-
-  @Override
-  public @NotNull ItemStack[] getExtraContents() {
-    return new ItemStack[4];
-  }
-
-  @Override
-  public @Nullable ItemStack getHelmet() {
-    return null;
-  }
-
-  @Override
-  public @Nullable ItemStack getChestplate() {
-    return null;
-  }
-
-  @Override
-  public @Nullable ItemStack getLeggings() {
-    return null;
-  }
-
-  @Override
-  public @Nullable ItemStack getBoots() {
-    return null;
-  }
-
-  @Override
-  public void setItem(@NotNull EquipmentSlot slot, @Nullable ItemStack item) {
-
-  }
-
-  @Override
-  public @Nullable ItemStack getItem(@NotNull EquipmentSlot slot) {
-    return null;
-  }
-
-  @Override
-  public void setArmorContents(@Nullable ItemStack[] items) {
-
-  }
-
-  @Override
-  public void setExtraContents(@Nullable ItemStack[] items) {
-
-  }
-
-  @Override
-  public void setHelmet(@Nullable ItemStack helmet) {
-
-  }
-
-  @Override
-  public void setChestplate(@Nullable ItemStack chestplate) {
-
-  }
-
-  @Override
-  public void setLeggings(@Nullable ItemStack leggings) {
-
-  }
-
-  @Override
-  public void setBoots(@Nullable ItemStack boots) {
-
-  }
-
-  @Override
-  public @NotNull ItemStack getItemInMainHand() {
-    return new ItemStack(Material.AIR);
-  }
-
-  @Override
-  public void setItemInMainHand(@Nullable ItemStack item) {
-
-  }
-
-  @Override
-  public @NotNull ItemStack getItemInOffHand() {
-    return new ItemStack(Material.AIR);
-  }
-
-  @Override
-  public void setItemInOffHand(@Nullable ItemStack item) {
-
-  }
-
-  @Override
-  public @NotNull ItemStack getItemInHand() {
-    return new ItemStack(Material.AIR);
-  }
-
-  @Override
-  public void setItemInHand(@Nullable ItemStack stack) {
-
-  }
-
-  @Override
-  public int getHeldItemSlot() {
-    return 0;
-  }
-
-  @Override
-  public void setHeldItemSlot(int slot) {
-
-  }
-
-}

internal/v1_21_R3/src/main/java/com/lishid/openinv/internal/v1_21_R3/container/slot/Content.java

@@ -1,69 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R3.container.slot;
-
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.jetbrains.annotations.NotNull;
-
-/**
- * An interface defining behaviors for entries in a {@link Container}. Used to reduce duplicate content reordering.
- */
-public interface Content {
-
-  /**
-   * Update internal holder.
-   *
-   * @param holder the new holder
-   */
-  void setHolder(@NotNull ServerPlayer holder);
-
-  /**
-   * Get the current item.
-   *
-   * @return the current item
-   */
-  ItemStack get();
-
-  /**
-   * Remove the current item.
-   *
-   * @return the current item
-   */
-  ItemStack remove();
-
-  /**
-   * Remove some of the current item.
-   *
-   * @return the current item
-   */
-  ItemStack removePartial(int amount);
-
-  /**
-   * Set the current item. If slot is currently not usable, will drop item instead.
-   *
-   * @param itemStack the item to set
-   */
-  void set(ItemStack itemStack);
-
-  /**
-   * Get a {@link Slot} for use in a {@link net.minecraft.world.inventory.AbstractContainerMenu ContainerMenu}. Will
-   * impose any specific restrictions to insertion or removal.
-   *
-   * @param container the backing container
-   * @param slot the slot of the backing container represented
-   * @param x clientside x dimension from top left of inventory, not used
-   * @param y clientside y dimension from top left of inventory, not used
-   * @return a menu slot
-   */
-  Slot asSlot(Container container, int slot, int x, int y);
-
-  /**
-   * Get a loose Bukkit translation of what this slot stores. For example, any slot that drops items at the owner rather
-   * than insert them will report itself as being {@link org.bukkit.event.inventory.InventoryType.SlotType#OUTSIDE}.
-   *
-   * @return the closes Bukkit slot type
-   */
-  org.bukkit.event.inventory.InventoryType.SlotType getSlotType();
-
-}

internal/v1_21_R3/src/main/java/com/lishid/openinv/internal/v1_21_R3/container/slot/ContentCrafting.java

@@ -1,131 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R3.container.slot;
-
-import com.lishid.openinv.internal.v1_21_R3.container.Placeholders;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.ContainerHelper;
-import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.event.inventory.InventoryType;
-import org.jetbrains.annotations.NotNull;
-
-import java.util.List;
-
-/**
- * A slot in a survival crafting inventory. Unavailable when not online in a survival mode.
- */
-public class ContentCrafting implements Content {
-
-  private final int index;
-  private ServerPlayer holder;
-  private List<ItemStack> items;
-
-  public ContentCrafting(@NotNull ServerPlayer holder, int index) {
-    setHolder(holder);
-    this.index = index;
-  }
-
-  private boolean isAvailable() {
-    return isAvailable(holder);
-  }
-
-  static boolean isAvailable(@NotNull ServerPlayer holder) {
-    // Player must be online and not in creative - since the creative client is (semi-)authoritative,
-    // it ignores changes without extra help, and will delete the item as a result.
-    // Spectator mode is technically possible but may cause the item to be dropped if the client opens an inventory.
-    return holder.connection != null && !holder.connection.isDisconnected() && holder.gameMode.isSurvival();
-  }
-
-  @Override
-  public void setHolder(@NotNull ServerPlayer holder) {
-    this.holder = holder;
-    // Note: CraftingContainer#getItems is immutable! Be careful with updates.
-    this.items = holder.inventoryMenu.getCraftSlots().getContents();
-  }
-
-  @Override
-  public ItemStack get() {
-    return isAvailable() ? items.get(index) : ItemStack.EMPTY;
-  }
-
-  @Override
-  public ItemStack remove() {
-    if (!this.isAvailable()) {
-      return ItemStack.EMPTY;
-    }
-    ItemStack removed = items.remove(index);
-    if (removed.isEmpty()) {
-      return ItemStack.EMPTY;
-    }
-    holder.inventoryMenu.slotsChanged(holder.inventoryMenu.getCraftSlots());
-    return removed;
-  }
-
-  @Override
-  public ItemStack removePartial(int amount) {
-    if (!this.isAvailable()) {
-      return ItemStack.EMPTY;
-    }
-    ItemStack removed = ContainerHelper.removeItem(items, index, amount);
-    if (removed.isEmpty()) {
-      return ItemStack.EMPTY;
-    }
-    holder.inventoryMenu.slotsChanged(holder.inventoryMenu.getCraftSlots());
-    return removed;
-  }
-
-  @Override
-  public void set(ItemStack itemStack) {
-    if (isAvailable()) {
-      items.set(index, itemStack);
-      holder.inventoryMenu.slotsChanged(holder.inventoryMenu.getCraftSlots());
-    } else {
-      holder.drop(itemStack, false);
-    }
-  }
-
-  @Override
-  public Slot asSlot(Container container, int slot, int x, int y) {
-    return new SlotCrafting(container, slot, x, y);
-  }
-
-  @Override
-  public InventoryType.SlotType getSlotType() {
-    return isAvailable() ? InventoryType.SlotType.CRAFTING : InventoryType.SlotType.OUTSIDE;
-  }
-
-  public class SlotCrafting extends SlotPlaceholder {
-
-    private SlotCrafting(Container container, int index, int x, int y) {
-      super(container, index, x, y);
-    }
-
-    @Override
-    public ItemStack getOrDefault() {
-      return isAvailable() ? items.get(ContentCrafting.this.index) : Placeholders.survivalOnly(holder);
-    }
-
-    @Override
-    public boolean mayPickup(Player player) {
-      return isAvailable();
-    }
-
-    @Override
-    public boolean mayPlace(ItemStack itemStack) {
-      return isAvailable();
-    }
-
-    @Override
-    public boolean hasItem() {
-      return isAvailable() && super.hasItem();
-    }
-
-    @Override
-    public boolean isFake() {
-      return !isAvailable();
-    }
-
-  }
-
-}

internal/v1_21_R3/src/main/java/com/lishid/openinv/internal/v1_21_R3/container/slot/ContentCursor.java

@@ -1,117 +0,0 @@
-package com.lishid.openinv.internal.v1_21_R3.container.slot;
-
-import com.lishid.openinv.internal.v1_21_R3.container.Placeholders;
-import net.minecraft.server.level.ServerPlayer;
-import net.minecraft.world.Container;
-import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.inventory.Slot;
-import net.minecraft.world.item.ItemStack;
-import org.bukkit.event.inventory.InventoryType;
-import org.jetbrains.annotations.NotNull;
-
-/**
- * A slot wrapping the active menu's cursor. Unavailable when not online in a survival mode.
- */
-public class ContentCursor implements Content {
-
-  private @NotNull ServerPlayer holder;
-
-  public ContentCursor(@NotNull ServerPlayer holder) {
-    this.holder = holder;
-  }
-
-  @Override
-  public void setHolder(@NotNull ServerPlayer holder) {
-    this.holder = holder;
-  }
-
-  @Override
-  public ItemStack get() {
-    return isAvailable() ? holder.containerMenu.getCarried() : ItemStack.EMPTY;
-  }
-
-  @Override
-  public ItemStack remove() {
-    ItemStack carried = holder.containerMenu.getCarried();
-    holder.containerMenu.setCarried(ItemStack.EMPTY);
-    return carried;
-  }
-
-  @Override
-  public ItemStack removePartial(int amount) {
-    ItemStack carried = holder.containerMenu.getCarried();
-    if (!carried.isEmpty() && carried.getCount() >= amount) {
-      ItemStack value = carried.split(amount);
-      if (carried.isEmpty()) {
-        holder.containerMenu.setCarried(ItemStack.EMPTY);
-      }
-      return value;
-    }
-    return ItemStack.EMPTY;
-  }
-
-  @Override
-  public void set(ItemStack itemStack) {
-    if (isAvailable()) {
-      holder.containerMenu.setCarried(itemStack);
-    } else {
-      holder.drop(itemStack, false);
-    }
-  }
-
-  private boolean isAvailable() {
-    // Player must be online and not in creative - since the creative client is (semi-)authoritative,
-    // it ignores changes without extra help, and will delete the item as a result.
-    // Spectator mode is technically possible but may cause the item to be dropped if the client opens an inventory.
-    return holder.connection != null && !holder.connection.isDisconnected() && holder.gameMode.isSurvival();
-  }
-
-  @Override
-  public Slot asSlot(Container container, int slot, int x, int y) {
-    return new SlotCursor(container, slot, x, y);
-  }
-
-  @Override
-  public InventoryType.SlotType getSlotType() {
-    // As close as possible to "not real"
-    return InventoryType.SlotType.OUTSIDE;
-  }
-
-  public class SlotCursor extends SlotPlaceholder {
-
-    private SlotCursor(Container container, int index, int x, int y) {
-      super(container, index, x, y);
-    }
-
-    @Override
-    public ItemStack getOrDefault() {
-      if (!isAvailable()) {
-        return Placeholders.survivalOnly(holder);
-      }
-      ItemStack carried = holder.containerMenu.getCarried();
-      return carried.isEmpty() ? Placeholders.cursor : carried;
-    }
-
-    @Override
-    public boolean mayPickup(Player player) {
-      return isAvailable();
-    }
-
-    @Override
-    public boolean mayPlace(ItemStack itemStack) {
-      return isAvailable();
-    }
-
-    @Override
-    public boolean hasItem() {
-      return isAvailable() && super.hasItem();
-    }
-
-    @Override
-    public boolean isFake() {
-      return true;
-    }
-
-  }
-
-}