ui: Implement "window doesn't respond" dialog on gnome-shell

This does allow us to use ClutterActors instead of lousy legacy tools
meant for shell scripting.

https://bugzilla.gnome.org/show_bug.cgi?id=762083

src/gnome-shell-plugin.c

@@ -88,6 +88,8 @@ static void gnome_shell_plugin_confirm_display_change (MetaPlugin *plugin);
 
 static const MetaPluginInfo *gnome_shell_plugin_plugin_info   (MetaPlugin *plugin);
 
+static MetaCloseDialog * gnome_shell_plugin_create_close_dialog (MetaPlugin *plugin,
+                                                              MetaWindow *window);
 
 #define GNOME_TYPE_SHELL_PLUGIN            (gnome_shell_plugin_get_type ())
 #define GNOME_SHELL_PLUGIN(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GNOME_TYPE_SHELL_PLUGIN, GnomeShellPlugin))
@@ -149,6 +151,8 @@ gnome_shell_plugin_class_init (GnomeShellPluginClass *klass)
   plugin_class->confirm_display_change = gnome_shell_plugin_confirm_display_change;
 
   plugin_class->plugin_info       = gnome_shell_plugin_plugin_info;
+
+  plugin_class->create_close_dialog = gnome_shell_plugin_create_close_dialog;
 }
 
 static void
@@ -425,3 +429,10 @@ MetaPluginInfo *gnome_shell_plugin_plugin_info (MetaPlugin *plugin)
 
   return &info;
 }
+
+static MetaCloseDialog *
+gnome_shell_plugin_create_close_dialog (MetaPlugin *plugin,
+                                        MetaWindow *window)
+{
+  return _shell_wm_create_close_dialog (get_shell_wm (), window);
+}

src/shell-wm-private.h

@@ -52,6 +52,9 @@ gboolean _shell_wm_filter_keybinding (ShellWM             *wm,
 
 void _shell_wm_confirm_display_change (ShellWM            *wm);
 
+MetaCloseDialog * _shell_wm_create_close_dialog (ShellWM     *wm,
+                                                 MetaWindow  *window);
+
 G_END_DECLS
 
 #endif /* __SHELL_WM_PRIVATE_H__ */

src/shell-wm.c

@@ -33,6 +33,7 @@ enum
   SHOW_WINDOW_MENU,
   FILTER_KEYBINDING,
   CONFIRM_DISPLAY_CHANGE,
+  CREATE_CLOSE_DIALOG,
 
   LAST_SIGNAL
 };
@@ -168,6 +169,22 @@ shell_wm_class_init (ShellWMClass *klass)
                   0,
                   NULL, NULL, NULL,
                   G_TYPE_NONE, 0);
+  /**
+   * ShellWM::create-close-dialog:
+   * @wm: The WM
+   * @window: The window to create the dialog for
+   *
+   * Creates a close dialog for the given window.
+   *
+   * Returns: (transfer full): The close dialog instance.
+   */
+  shell_wm_signals[CREATE_CLOSE_DIALOG] =
+    g_signal_new ("create-close-dialog",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  0,
+                  NULL, NULL, NULL,
+                  META_TYPE_CLOSE_DIALOG, 1, META_TYPE_WINDOW);
 }
 
 void
@@ -386,6 +403,17 @@ _shell_wm_confirm_display_change (ShellWM *wm)
   g_signal_emit (wm, shell_wm_signals[CONFIRM_DISPLAY_CHANGE], 0);
 }
 
+MetaCloseDialog *
+_shell_wm_create_close_dialog (ShellWM    *wm,
+                               MetaWindow *window)
+{
+  MetaCloseDialog *dialog;
+
+  g_signal_emit (wm, shell_wm_signals[CREATE_CLOSE_DIALOG], 0, window, &dialog);
+
+  return dialog;
+}
+
 /**
  * shell_wm_new:
  * @plugin: the #MetaPlugin