[gtk+] Disable frame sync for GtkPlug

[Owen Taylor <otaylor src gnome org>]

commit c7574bb6c88816f6bc85e414253388fecc26d367
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Wed Jun 26 10:05:38 2013 -0400

    Disable frame sync for GtkPlug
    
    Plug windows weren't redrawing properly because the embedded
    window was expecting to get messages for each frame from the
    compositor, but the compositor doesn't know about embedded
    windows. Simply disable frame sync for GtkPlug's GdkWindow -
    extending XEMBED to handle frame sync isn't interesting
    at this point.
    
    A new API gdk_x11_window_set_frame_sync_enabled() is added
    to allow this to be done.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=701613

 gdk/x11/gdkwindow-x11.c |   35 ++++++++++++++++++++++++++++++++++-
 gdk/x11/gdkwindow-x11.h |    3 +++
 gdk/x11/gdkx11window.h  |    4 ++++
 gtk/gtkplug.c           |    7 +++++++
 4 files changed, 48 insertions(+), 1 deletions(-)
---
diff --git a/gdk/x11/gdkwindow-x11.c b/gdk/x11/gdkwindow-x11.c
index 3fe545c..8eca50c 100644
--- a/gdk/x11/gdkwindow-x11.c
+++ b/gdk/x11/gdkwindow-x11.c
@@ -157,6 +157,7 @@ gdk_window_impl_x11_init (GdkWindowImplX11 *impl)
   impl->device_cursor = g_hash_table_new_full (NULL, NULL,
                                                NULL, g_object_unref);
   impl->window_scale = 1;
+  impl->frame_sync_enabled = TRUE;
 }
 
 GdkToplevelX11 *
@@ -403,7 +404,8 @@ gdk_x11_window_end_frame (GdkWindow *window)
                       impl->toplevel->extended_update_counter,
                       impl->toplevel->current_counter_value);
 
-      if (gdk_x11_screen_supports_net_wm_hint (gdk_window_get_screen (window),
+      if (impl->frame_sync_enabled &&
+          gdk_x11_screen_supports_net_wm_hint (gdk_window_get_screen (window),
                                               gdk_atom_intern_static_string ("_NET_WM_FRAME_DRAWN")))
         {
           impl->toplevel->frame_pending = TRUE;
@@ -5443,6 +5445,37 @@ gdk_x11_window_get_scale_factor (GdkWindow *window)
   return impl->window_scale;
 }
 
+/**
+ * gdk_x11_window_set_frame_sync_enabled:
+ * @window: (type GdkX11Window): a native #GdkWindow
+ * @frame_sync_enabled: whether frame-synchronization should be enabled
+ *
+ * This function can be used to disable frame synchronization for a window.
+ * Normally frame synchronziation will be enabled or disabled based on whether
+ * the system has a compositor that supports frame synchronization, but if
+ * the window is not directly managed by the window manager, then frame
+ * synchronziation may need to be disabled. This is the case for a window
+ * embedded via the XEMBED protocol.
+ *
+ * Since: 3.8
+ */
+void
+gdk_x11_window_set_frame_sync_enabled (GdkWindow *window,
+                                       gboolean   frame_sync_enabled)
+{
+  /* Try to ensure the window has a native window */
+  if (!_gdk_window_has_impl (window))
+    gdk_window_ensure_native (window);
+
+  if (!GDK_WINDOW_IS_X11 (window))
+    {
+      g_warning (G_STRLOC " drawable is not a native X11 window");
+      return;
+    }
+
+  GDK_WINDOW_IMPL_X11 (window->impl)->frame_sync_enabled = FALSE;
+}
+
 static void
 gdk_window_impl_x11_class_init (GdkWindowImplX11Class *klass)
 {
diff --git a/gdk/x11/gdkwindow-x11.h b/gdk/x11/gdkwindow-x11.h
index 1c50cf4..92db3d8 100644
--- a/gdk/x11/gdkwindow-x11.h
+++ b/gdk/x11/gdkwindow-x11.h
@@ -74,6 +74,7 @@ struct _GdkWindowImplX11
                            * unset during resizing and scaling */
   guint override_redirect : 1;
   guint frame_clock_connected : 1;
+  guint frame_sync_enabled : 1;
 
   cairo_surface_t *cairo_surface;
 
@@ -176,6 +177,8 @@ GType gdk_window_impl_x11_get_type (void);
 
 void            gdk_x11_window_set_user_time        (GdkWindow *window,
                                                     guint32    timestamp);
+void            gdk_x11_window_set_frame_sync_enabled (GdkWindow *window,
+                                                       gboolean   frame_sync_enabled);
 
 GdkToplevelX11 *_gdk_x11_window_get_toplevel        (GdkWindow *window);
 void            _gdk_x11_window_tmp_unset_bg        (GdkWindow *window,
diff --git a/gdk/x11/gdkx11window.h b/gdk/x11/gdkx11window.h
index bf4d553..1503402 100644
--- a/gdk/x11/gdkx11window.h
+++ b/gdk/x11/gdkx11window.h
@@ -71,6 +71,10 @@ void     gdk_x11_window_set_hide_titlebar_when_maximized (GdkWindow *window,
 GDK_AVAILABLE_IN_ALL
 void     gdk_x11_window_move_to_current_desktop (GdkWindow   *window);
 
+GDK_AVAILABLE_IN_3_8
+void     gdk_x11_window_set_frame_sync_enabled (GdkWindow *window,
+                                                gboolean   frame_sync_enabled);
+
 /**
  * GDK_WINDOW_XDISPLAY:
  * @win: a #GdkWindow.
diff --git a/gtk/gtkplug.c b/gtk/gtkplug.c
index 788be1a..c2fb493 100644
--- a/gtk/gtkplug.c
+++ b/gtk/gtkplug.c
@@ -1053,6 +1053,13 @@ gtk_plug_realize (GtkWidget *widget)
       else /* If it's a passive plug, we use the root window */
         gdk_window = gdk_window_new (gtk_widget_get_root_window (widget),
                                      &attributes, attributes_mask);
+      /* Because the window isn't known to the window manager,
+       * frame sync won't work. In theory, XEMBED could be extended
+       * so that embedder did frame sync like a window manager, but
+       * it's just not worth the effort considering the current
+       * minimal use of XEMBED.
+       */
+      gdk_x11_window_set_frame_sync_enabled (gdk_window, FALSE);
       gtk_widget_set_window (widget, gdk_window);
 
       gdk_display_sync (gtk_widget_get_display (widget));