Update Signal methods of MousePosition.vala

src/ColorPicker.vala

@@ -20,27 +20,55 @@
 */
 
 namespace ColorPicker {
-    int main (string[] args) {
-        Gtk.init (ref args);
+    
+    public class ScreenshotApp : Granite.Application {
+        public static int main (string[] args) {
+            Gtk.init (ref args);
 
-        var window = new Gtk.Window ();
-        window.title = "Hello World!";
-        window.set_border_width (12);
-        window.set_position (Gtk.WindowPosition.CENTER);
-        window.set_default_size (350, 70);
-        window.destroy.connect (Gtk.main_quit);
+            var window = new Gtk.Window ();
+            window.title = "Hello World!";
+            window.set_border_width (12);
+            window.set_position (Gtk.WindowPosition.CENTER);
+            window.set_default_size (350, 70);
+            window.destroy.connect (Gtk.main_quit);
 
-        var button_hello = new Gtk.Button.with_label ("Click me!");
-        button_hello.clicked.connect (() => {
-            button_hello.label = "Hello World!";
-            button_hello.set_sensitive (false);
-        });
+            var button_hello = new Gtk.Button.with_label ("Click me!");
+            button_hello.clicked.connect (() => {
+                var mouse_position = new ColorPicker.Widgets.MousePosition ();
+                mouse_position.show_all ();
+                
+                mouse_position.moved.connect ((t, color) => {
+                    button_hello.label = color.to_string ();
+                    //stdout.printf((string) mouse_position.get_point().x + "\n");
+                    //button_hello.label = (string) mouse_position.get_point().x; 
+                });                
 
-        window.add (button_hello);
-        window.show_all ();
+                mouse_position.cancelled.connect (() => {
+                    mouse_position.close ();
+                    window.present ();
+                });
+
+                var win = mouse_position.get_window ();
+                
+                mouse_position.picked.connect ((t, color) => {
+                
+                    mouse_position.close ();
+                    window.present ();
+                    /*
+                    stdout.printf("picked\n");
+                    Gdk.Point p = mouse_position.get_point();
+                    button_hello.label = (string) mouse_position.get_point().x; 
+                    mouse_position.close ();*/
+                });
+            });
+
+            window.add (button_hello);
+            window.show_all ();
 
 
-        Gtk.main ();
-        return 0;   
+            Gtk.main ();
+            return 0;   
+        }
+
     }
 }

src/ColorPicker.vala~

@@ -0,0 +1,46 @@
+/*
+* Copyright (c) 2017 Ronny Dobra (https://github.com/RonnyDo/ColorPicker)
+*
+* 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; either
+* version 2 of the License, or (at your option) any later version.
+*
+* 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, write to the
+* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+* Boston, MA 02110-1301 USA
+*
+* Authored by: Ronny Dobra <ronnydobra at arcor dot de>
+*/
+
+namespace ColorPicker {
+    int main (string[] args) {
+        Gtk.init (ref args);
+
+        var window = new Gtk.Window ();
+        window.title = "Hello World!";
+        window.set_border_width (12);
+        window.set_position (Gtk.WindowPosition.CENTER);
+        window.set_default_size (350, 70);
+        window.destroy.connect (Gtk.main_quit);
+
+        var button_hello = new Gtk.Button.with_label ("Click me!");
+        button_hello.clicked.connect (() => {
+            button_hello.label = "Hello World!";
+            button_hello.set_sensitive (false);
+        });
+
+        window.add (button_hello);
+        window.show_all ();
+
+
+        Gtk.main ();
+        return 0;   
+    }
+}

src/Widgets/MousePosition.vala

@@ -0,0 +1,146 @@
+// inspired by https://github.com/elementary/screenshot-tool/blob/master/src/Widgets/SelectionArea.vala
+
+namespace ColorPicker.Widgets {
+
+    public class MousePosition : Granite.Widgets.CompositedWindow {
+        public signal void picked (Gdk.RGBA color);
+        public signal void cancelled ();
+        public signal void moved (Gdk.RGBA color);
+
+        private Gdk.Point point;
+
+        construct {
+            type = Gtk.WindowType.POPUP;
+        }
+
+        public MousePosition () {
+            stick ();
+            set_resizable (true);
+            set_deletable (false);
+            set_has_resize_grip (false);
+            set_skip_taskbar_hint (true);
+            set_skip_pager_hint (true);
+            set_keep_above (true);
+
+            var screen = get_screen ();
+            set_default_size (screen.get_width (), screen.get_height ());
+        }   
+
+        
+        public override bool button_release_event (Gdk.EventButton e) {
+            if (e.button != 1) {
+                return true;
+            }
+
+            Gdk.RGBA color = get_color_at ((int) e.x_root, (int) e.y_root);
+            picked (color);
+
+            return true;            
+        }
+
+
+        public override bool motion_notify_event (Gdk.EventMotion e) {
+            Gdk.RGBA color = get_color_at ((int) e.x_root, (int) e.y_root);
+            moved (color);
+            
+            return true;            
+        }
+
+
+        public override bool key_press_event (Gdk.EventKey e) {
+            if (e.keyval == Gdk.Key.Escape) {
+                cancelled ();
+            }
+
+            return true;            
+        }
+
+        public Gdk.RGBA get_color_at (int x, int y) {
+            Gdk.Window win = Gdk.get_default_root_window ();
+            Gdk.Pixbuf? pixbuf = Gdk.pixbuf_get_from_window (win, x, y, 1, 1);
+
+            if (pixbuf != null) {                
+                // see https://hackage.haskell.org/package/gtk3-0.14.6/docs/Graphics-UI-Gtk-Gdk-Pixbuf.html
+                uint8 red = pixbuf.get_pixels()[0];
+                uint8 green = pixbuf.get_pixels()[1];
+                uint8 blue = pixbuf.get_pixels()[2];
+                
+                Gdk.RGBA color = Gdk.RGBA();
+                string spec = "rgb(" + red.to_string() + "," + green.to_string() + "," + blue.to_string() + ")";
+                if (color.parse (spec)) {
+                    return color;                   
+                } else {
+                    stdout.printf("ERROR: Parse pixel rgb values failed.");
+                }                
+            }
+            
+            // fallback: default RGBA color
+            stdout.printf("ERROR: Gdk.pixbuf_get_from_window failed");
+            return Gdk.RGBA ();
+        }
+
+
+        public override void show_all () {
+            base.show_all ();
+            var manager = Gdk.Display.get_default ().get_device_manager ();
+            var pointer = manager.get_client_pointer ();
+            var keyboard = pointer.get_associated_device ();
+            var window = get_window ();
+
+            var status = pointer.grab (window,
+                        Gdk.GrabOwnership.NONE,
+                        false,
+                        Gdk.EventMask.BUTTON_PRESS_MASK | Gdk.EventMask.BUTTON_RELEASE_MASK | Gdk.EventMask.POINTER_MOTION_MASK,
+                        new Gdk.Cursor.for_display (window.get_display (), Gdk.CursorType.CROSSHAIR),
+                        Gtk.get_current_event_time ());
+
+            if (status != Gdk.GrabStatus.SUCCESS) {
+                pointer.ungrab (Gtk.get_current_event_time ());
+            }
+
+            if (keyboard != null) {
+                status = keyboard.grab (window,
+                        Gdk.GrabOwnership.NONE,
+                        false,
+                        Gdk.EventMask.KEY_PRESS_MASK,
+                        null,
+                        Gtk.get_current_event_time ());
+
+                if (status != Gdk.GrabStatus.SUCCESS) {
+                    keyboard.ungrab (Gtk.get_current_event_time ());
+                }                
+            }
+        }
+
+        public new void close () {
+            get_window ().set_cursor (null);
+            base.close ();
+        }
+
+        /*
+        public override bool draw (Cairo.Context ctx) {
+            if (!dragging) {
+                return true;
+            }
+
+            int w = get_allocated_width ();
+            int h = get_allocated_height ();
+
+            ctx.rectangle (0, 0, w, h);
+            ctx.set_source_rgba (0.1, 0.1, 0.1, 0.2);
+            ctx.fill ();
+
+            ctx.rectangle (0, 0, w, h);
+            ctx.set_source_rgb (0.7, 0.7, 0.7);
+            ctx.set_line_width (1.0);
+            ctx.stroke ();
+
+            return base.draw (ctx);
+        }
+    */
+
+
+
+    }
+
+}