Don't use ClutterX11TexturePixmap directly to embed docked windows

Previously when a client requests that a window should be docked the
shell would reparent the socket window onto the stage's window and
then use ClutterX11TexturePixmap to get a texture to represent the
window. This will not work if Clutter is no longer using the X11
winsys for example if it becomes its own display server. Instead this
patch leaves the socket window as a child of the root window and lets
mutter create a MetaWindow out of it. If Mutter is acting as a display
server then this mechanism will still work via the headless x server.

The ShellGtkEmbed instance now registers for notification of the
‘window-created’ signal of the display so that it can find the
MetaWindow that gets created to represent the socket window. When this
window is found it is prevented from being displayed on the screen by
setting the actor's opacity to 0. An input shape is then set on the
window to prevent it receiving any input.

Instead of being a subclass of ClutterX11TexturePixmap, ShellGtkEmbed
is now a subclass of ClutterClone. When the MetaWindow is found for
the socket window the clone's source is set to the invisible actor for
the window so it can be displayed in the panel as before.

The ShellEmbeddedWindow no longer needs to know what the stage is
because it no longer reparents the socket window. Therefore the
ShellTrayManager doesn't need to know the stage either so
shell_tray_manager_manage_stage has been replaced with just
shell_tray_manager_manage_screen.

https://bugzilla.gnome.org/show_bug.cgi?id=693438

js/ui/notificationDaemon.js

@@ -244,7 +244,7 @@ const NotificationDaemon = new Lang.Class({
         Main.overview.connect('hidden',
             Lang.bind(this, this._onFocusAppChanged));
 
-        this._trayManager.manage_stage(global.stage, Main.messageTray.actor);
+        this._trayManager.manage_screen(global.screen, Main.messageTray.actor);
     },
 
     _imageForNotificationData: function(hints) {

src/shell-embedded-window.c

@@ -8,9 +8,7 @@
 #include "shell-embedded-window-private.h"
 
 /* This type is a subclass of GtkWindow that ties the window to a
- * ShellGtkEmbed; the window is reparented into the stage
+ * ShellGtkEmbed; the resizing logic is bound to the clutter logic.
- * window for the actor and the resizing logic is bound to the clutter
- * logic.
  *
  * The typical usage we might expect is
  *
@@ -28,16 +26,13 @@
 G_DEFINE_TYPE (ShellEmbeddedWindow, shell_embedded_window, GTK_TYPE_WINDOW);
 
 enum {
-   PROP_0,
+   PROP_0
-
-   PROP_STAGE
 };
 
 struct _ShellEmbeddedWindowPrivate {
   ShellGtkEmbed *actor;
 
   GdkRectangle position;
-  Window stage_xwindow;
 };
 
 /*
@@ -80,27 +75,6 @@ shell_embedded_window_hide (GtkWidget *widget)
   GTK_WIDGET_CLASS (shell_embedded_window_parent_class)->hide (widget);
 }
 
-static void
-shell_embedded_window_realize (GtkWidget *widget)
-{
-  ShellEmbeddedWindow *window = SHELL_EMBEDDED_WINDOW (widget);
-
-  GTK_WIDGET_CLASS (shell_embedded_window_parent_class)->realize (widget);
-
-
-  /* Using XReparentWindow() is simpler than using gdk_window_reparent(),
-   * since it avoids maybe having to create a new foreign GDK window for
-   * the stage. However, GDK will be left thinking that the parent of
-   * window->window is the root window - it's not immediately clear
-   * to me whether that is more or less likely to cause problems than
-   * modifying the GDK hierarchy.
-   */
-  XReparentWindow (GDK_DISPLAY_XDISPLAY (gtk_widget_get_display (widget)),
-                   gdk_x11_window_get_xid (gtk_widget_get_window (widget)),
-                   window->priv->stage_xwindow,
-                   window->priv->position.x, window->priv->position.y);
-}
-
 static gboolean
 shell_embedded_window_configure_event (GtkWidget         *widget,
                                        GdkEventConfigure *event)
@@ -127,27 +101,6 @@ shell_embedded_window_check_resize (GtkContainer *container)
     clutter_actor_queue_relayout (CLUTTER_ACTOR (window->priv->actor));
 }
 
-static void
-shell_embedded_window_set_property (GObject         *object,
-                                    guint            prop_id,
-                                    const GValue    *value,
-                                    GParamSpec      *pspec)
-{
-  ShellEmbeddedWindow *window = SHELL_EMBEDDED_WINDOW (object);
-
-  switch (prop_id)
-    {
-    case PROP_STAGE:
-      window->priv->stage_xwindow =
-        clutter_x11_get_stage_window (g_value_get_object (value));
-      break;
-
-    default:
-      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
-      break;
-    }
-}
-
 static GObject *
 shell_embedded_window_constructor (GType                  gtype,
                                    guint                  n_properties,
@@ -182,23 +135,13 @@ shell_embedded_window_class_init (ShellEmbeddedWindowClass *klass)
 
   g_type_class_add_private (klass, sizeof (ShellEmbeddedWindowPrivate));
 
-  object_class->set_property    = shell_embedded_window_set_property;
   object_class->constructor     = shell_embedded_window_constructor;
 
   widget_class->show            = shell_embedded_window_show;
   widget_class->hide            = shell_embedded_window_hide;
-  widget_class->realize         = shell_embedded_window_realize;
   widget_class->configure_event = shell_embedded_window_configure_event;
 
   container_class->check_resize    = shell_embedded_window_check_resize;
-
-  g_object_class_install_property (object_class,
-                                   PROP_STAGE,
-                                   g_param_spec_object ("stage",
-                                                        "Stage",
-                                                        "ClutterStage to embed on",
-                                                        CLUTTER_TYPE_STAGE,
-                                                        G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY));
 }
 
 static void
@@ -282,9 +225,8 @@ _shell_embedded_window_unmap (ShellEmbeddedWindow *window)
  * Public API
  */
 GtkWidget *
-shell_embedded_window_new (ClutterStage *stage)
+shell_embedded_window_new (void)
 {
   return g_object_new (SHELL_TYPE_EMBEDDED_WINDOW,
-                       "stage", stage,
                        NULL);
 }

src/shell-embedded-window.h

@@ -30,6 +30,6 @@ struct _ShellEmbeddedWindowClass
 };
 
 GType shell_embedded_window_get_type (void) G_GNUC_CONST;
-GtkWidget *shell_embedded_window_new (ClutterStage *stage);
+GtkWidget *shell_embedded_window_new (void);
 
 #endif /* __SHELL_EMBEDDED_WINDOW_H__ */

src/shell-gtk-embed.c

@@ -3,8 +3,11 @@
 #include "config.h"
 
 #include "shell-embedded-window-private.h"
+#include "shell-global.h"
 
 #include <gdk/gdkx.h>
+#include <meta/display.h>
+#include <meta/window.h>
 
 enum {
    PROP_0,
@@ -15,9 +18,14 @@ enum {
 struct _ShellGtkEmbedPrivate
 {
   ShellEmbeddedWindow *window;
+
+  ClutterActor *window_actor;
+  guint window_actor_destroyed_handler;
+
+  guint window_created_handler;
 };
 
-G_DEFINE_TYPE (ShellGtkEmbed, shell_gtk_embed, CLUTTER_X11_TYPE_TEXTURE_PIXMAP);
+G_DEFINE_TYPE (ShellGtkEmbed, shell_gtk_embed, CLUTTER_TYPE_CLONE);
 
 static void shell_gtk_embed_set_window (ShellGtkEmbed       *embed,
                                         ShellEmbeddedWindow *window);
@@ -30,39 +38,106 @@ shell_gtk_embed_on_window_destroy (GtkWidget     *object,
 }
 
 static void
-shell_gtk_embed_on_window_realize (GtkWidget     *widget,
+shell_gtk_embed_remove_window_actor (ShellGtkEmbed *embed)
+{
+  ShellGtkEmbedPrivate *priv = embed->priv;
+
+  if (priv->window_actor)
+    {
+      g_signal_handler_disconnect (priv->window_actor,
+                                   priv->window_actor_destroyed_handler);
+      priv->window_actor_destroyed_handler = 0;
+
+      g_object_unref (priv->window_actor);
+      priv->window_actor = NULL;
+    }
+
+  clutter_clone_set_source (CLUTTER_CLONE (embed), NULL);
+}
+
+static void
+shell_gtk_embed_window_created_cb (MetaDisplay   *display,
+                                   MetaWindow    *window,
                                    ShellGtkEmbed *embed)
 {
-  /* Here automatic=FALSE means to use CompositeRedirectManual.
+  ShellGtkEmbedPrivate *priv = embed->priv;
-   * That is, the X server shouldn't draw the window onto the
+  Window xwindow = meta_window_get_xwindow (window);
-   * screen.
+  GdkWindow *gdk_window = gtk_widget_get_window (GTK_WIDGET (priv->window));
-   */
+
-  clutter_x11_texture_pixmap_set_window (CLUTTER_X11_TEXTURE_PIXMAP (embed),
+  if (xwindow == gdk_x11_window_get_xid (gdk_window))
-                                         gdk_x11_window_get_xid (gtk_widget_get_window (widget)),
+    {
-                                         FALSE);
+      ClutterActor *window_actor =
+        CLUTTER_ACTOR (meta_window_get_compositor_private (window));
+      MetaDisplay *display = shell_global_get_display (shell_global_get ());
+      GCallback remove_cb = G_CALLBACK (shell_gtk_embed_remove_window_actor);
+      cairo_region_t *empty_region;
+
+      clutter_clone_set_source (CLUTTER_CLONE (embed), window_actor);
+
+      /* We want to explicitly clear the clone source when the window
+         actor is destroyed because otherwise we might end up keeping
+         it alive after it has been disposed. Otherwise this can cause
+         a crash if there is a paint after mutter notices that the top
+         level window has been destroyed, which causes it to dispose
+         the window, and before the tray manager notices that the
+         window is gone which would otherwise reset the window and
+         unref the clone */
+      priv->window_actor = g_object_ref (window_actor);
+      priv->window_actor_destroyed_handler =
+        g_signal_connect_swapped (window_actor,
+                                  "destroy",
+                                  remove_cb,
+                                  embed);
+
+      /* Hide the original actor otherwise it will appear in the scene
+         as a normal window */
+      clutter_actor_set_opacity (window_actor, 0);
+
+      /* Set an empty input shape on the window so that it can't get
+         any input. This probably isn't the ideal way to acheive this.
+         It would probably be better to force the window to go behind
+         Mutter's guard window, but this is quite difficult to do as
+         Mutter doesn't manage the stacking for override redirect
+         windows and the guard window is repeatedly lowered to the
+         bottom of the stack. */
+      empty_region = cairo_region_create ();
+      gdk_window_input_shape_combine_region (gdk_window,
+                                             empty_region,
+                                             0, 0 /* offset x/y */);
+      cairo_region_destroy (empty_region);
+
+      /* Now that we've found the window we don't need to listen for
+         new windows anymore */
+      g_signal_handler_disconnect (display,
+                                   priv->window_created_handler);
+      priv->window_created_handler = 0;
+    }
 }
 
 static void
 shell_gtk_embed_set_window (ShellGtkEmbed       *embed,
                             ShellEmbeddedWindow *window)
 {
+  MetaDisplay *display = shell_global_get_display (shell_global_get ());
 
   if (embed->priv->window)
     {
+      if (embed->priv->window_created_handler)
+        {
+          g_signal_handler_disconnect (display,
+                                       embed->priv->window_created_handler);
+          embed->priv->window_created_handler = 0;
+        }
+
+      shell_gtk_embed_remove_window_actor (embed);
+
       _shell_embedded_window_set_actor (embed->priv->window, NULL);
 
       g_object_unref (embed->priv->window);
 
-      clutter_x11_texture_pixmap_set_window (CLUTTER_X11_TEXTURE_PIXMAP (embed),
-                                             None,
-                                             FALSE);
-
       g_signal_handlers_disconnect_by_func (embed->priv->window,
                                             (gpointer)shell_gtk_embed_on_window_destroy,
                                             embed);
-      g_signal_handlers_disconnect_by_func (embed->priv->window,
-                                            (gpointer)shell_gtk_embed_on_window_realize,
-                                            embed);
     }
 
   embed->priv->window = window;
@@ -75,11 +150,14 @@ shell_gtk_embed_set_window (ShellGtkEmbed       *embed,
 
       g_signal_connect (embed->priv->window, "destroy",
                         G_CALLBACK (shell_gtk_embed_on_window_destroy), embed);
-      g_signal_connect (embed->priv->window, "realize",
-                        G_CALLBACK (shell_gtk_embed_on_window_realize), embed);
 
-      if (gtk_widget_get_realized (GTK_WIDGET (window)))
+      /* Listen for new windows so we can detect when Mutter has
-        shell_gtk_embed_on_window_realize (GTK_WIDGET (embed->priv->window), embed);
+         created a MutterWindow for this window */
+      embed->priv->window_created_handler =
+        g_signal_connect (display,
+                          "window-created",
+                          G_CALLBACK (shell_gtk_embed_window_created_cb),
+                          embed);
     }
 
   clutter_actor_queue_relayout (CLUTTER_ACTOR (embed));
@@ -260,11 +338,6 @@ shell_gtk_embed_init (ShellGtkEmbed *embed)
 {
   embed->priv = G_TYPE_INSTANCE_GET_PRIVATE (embed, SHELL_TYPE_GTK_EMBED,
                                              ShellGtkEmbedPrivate);
-
-  /* automatic here means whether ClutterX11TexturePixmap should
-   * process damage update and refresh the pixmap itself.
-   */
-  clutter_x11_texture_pixmap_set_automatic (CLUTTER_X11_TEXTURE_PIXMAP (embed), TRUE);
 }
 
 /*

src/shell-gtk-embed.h

@@ -2,7 +2,7 @@
 #ifndef __SHELL_GTK_EMBED_H__
 #define __SHELL_GTK_EMBED_H__
 
-#include <clutter/x11/clutter-x11.h>
+#include <clutter/clutter.h>
 
 #include "shell-embedded-window.h"
 
@@ -19,14 +19,14 @@ typedef struct _ShellGtkEmbedPrivate ShellGtkEmbedPrivate;
 
 struct _ShellGtkEmbed
 {
-    ClutterX11TexturePixmap parent;
+    ClutterClone parent;
 
     ShellGtkEmbedPrivate *priv;
 };
 
 struct _ShellGtkEmbedClass
 {
-    ClutterX11TexturePixmapClass parent_class;
+    ClutterCloneClass parent_class;
 };
 
 GType shell_gtk_embed_get_type (void) G_GNUC_CONST;

src/shell-tray-icon.c

@@ -7,6 +7,7 @@
 #include "shell-window-tracker.h"
 #include "tray/na-tray-child.h"
 #include <gdk/gdkx.h>
+#include <X11/Xatom.h>
 #include "st.h"
 
 enum {

src/shell-tray-manager.c

@@ -17,7 +17,6 @@
 
 struct _ShellTrayManagerPrivate {
   NaTrayManager *na_manager;
-  ClutterStage *stage;
   ClutterColor bg_color;
 
   GHashTable *icons;
@@ -135,7 +134,6 @@ shell_tray_manager_finalize (GObject *object)
   ShellTrayManager *manager = SHELL_TRAY_MANAGER (object);
 
   g_object_unref (manager->priv->na_manager);
-  g_object_unref (manager->priv->stage);
   g_hash_table_destroy (manager->priv->icons);
 
   G_OBJECT_CLASS (shell_tray_manager_parent_class)->finalize (object);
@@ -219,42 +217,19 @@ shell_tray_manager_style_changed (StWidget *theme_widget,
 }
 
 void
-shell_tray_manager_manage_stage (ShellTrayManager *manager,
+shell_tray_manager_manage_screen (ShellTrayManager *manager,
-                                 ClutterStage     *stage,
+                                  MetaScreen       *screen,
                                   StWidget         *theme_widget)
 {
-  Window stage_xwindow;
-  GdkWindow *stage_window;
   GdkDisplay *display;
-  GdkScreen *screen;
+  GdkScreen *gdk_screen;
+  int screen_number;
 
-  g_return_if_fail (manager->priv->stage == NULL);
+  display = gdk_display_get_default ();
+  screen_number = meta_screen_get_screen_number (screen);
+  gdk_screen = gdk_display_get_screen (display, screen_number);
 
-  manager->priv->stage = g_object_ref (stage);
+  na_tray_manager_manage_screen (manager->priv->na_manager, gdk_screen);
-
-  stage_xwindow = clutter_x11_get_stage_window (stage);
-
-  /* This is a pretty ugly way to get the GdkScreen for the stage; it
-   *  will normally go through the foreign_new() case with a
-   *  round-trip to the X server, it might be nicer to pass the screen
-   *  in in some way. (The Clutter/Mutter combo is currently incapable
-   *  of multi-screen operation, so alternatively we could just assume
-   *  that clutter_x11_get_default_screen() gives us the right
-   *  screen.) We assume, in any case, that we are using the default
-   *  GDK display.
-   */
-  display = gdk_display_get_default();
-  stage_window = gdk_x11_window_lookup_for_display (display, stage_xwindow);
-  if (stage_window)
-    g_object_ref (stage_window);
-  else
-    stage_window = gdk_x11_window_foreign_new_for_display (display, stage_xwindow);
-
-  screen = gdk_window_get_screen (stage_window);
-
-  g_object_unref (stage_window);
-
-  na_tray_manager_manage_screen (manager->priv->na_manager, screen);
 
   g_signal_connect (theme_widget, "style-changed",
                     G_CALLBACK (shell_tray_manager_style_changed), manager);
@@ -320,7 +295,7 @@ na_tray_icon_added (NaTrayManager *na_manager, GtkWidget *socket,
    */
   na_tray_child_set_composited (NA_TRAY_CHILD (socket), FALSE);
 
-  win = shell_embedded_window_new (manager->priv->stage);
+  win = shell_embedded_window_new ();
   gtk_container_add (GTK_CONTAINER (win), socket);
 
   /* The visual of the socket matches that of its contents; make

src/shell-tray-manager.h

@@ -41,8 +41,8 @@ struct _ShellTrayManagerClass
 GType             shell_tray_manager_get_type     (void);
 
 ShellTrayManager *shell_tray_manager_new          (void);
-void              shell_tray_manager_manage_stage (ShellTrayManager *manager,
+void              shell_tray_manager_manage_screen (ShellTrayManager *manager,
-                                                   ClutterStage     *stage,
+                                                    MetaScreen       *screen,
                                                     StWidget         *theme_widget);
 
 G_END_DECLS