Send _NET_WM_FRAME_DRAWN messages

When the application provides the extended second counter for
_NET_WM_SYNC_REQUEST, send a client message with completion
information after the next redraw after each counter update
by the application.

https://bugzilla.gnome.org/show_bug.cgi?id=685463

src/compositor/compositor.c

@@ -470,6 +470,16 @@ meta_check_end_modal (MetaScreen *screen)
     }
 }
 
+static void
+after_stage_paint (ClutterActor   *stage,
+                   MetaCompScreen *info)
+{
+  GList *l;
+
+  for (l = info->windows; l; l = l->next)
+    meta_window_actor_post_paint (l->data);
+}
+
 void
 meta_compositor_manage_screen (MetaCompositor *compositor,
                                MetaScreen     *screen)
@@ -539,6 +549,8 @@ meta_compositor_manage_screen (MetaCompositor *compositor,
   meta_screen_set_cm_selection (screen);
 
   info->stage = clutter_stage_new ();
+  g_signal_connect_after (info->stage, "paint",
+                          G_CALLBACK (after_stage_paint), info);
 
   meta_screen_get_size (screen, &width, &height);
   clutter_actor_realize (info->stage);

src/compositor/meta-window-actor-private.h

@@ -28,6 +28,7 @@ void meta_window_actor_process_damage (MetaWindowActor    *self,
                                        XDamageNotifyEvent *event);
 
 void meta_window_actor_pre_paint      (MetaWindowActor    *self);
+void meta_window_actor_post_paint     (MetaWindowActor    *self);
 
 void meta_window_actor_invalidate_shadow (MetaWindowActor *self);
 

src/compositor/meta-window-actor.c

@@ -97,6 +97,10 @@ struct _MetaWindowActorPrivate
   gint              map_in_progress;
   gint              destroy_in_progress;
 
+  /* If non-zero, the client needs to be sent a _NET_WM_FRAME_DRAWN
+   * client message with this value */
+  gint64            frame_drawn_serial;
+
   guint		    visible                : 1;
   guint		    mapped                 : 1;
   guint		    argb32                 : 1;
@@ -2307,6 +2311,43 @@ meta_window_actor_pre_paint (MetaWindowActor *self)
   check_needs_pixmap (self);
   check_needs_reshape (self);
   check_needs_shadow (self);
+
+  if (priv->window->needs_frame_drawn)
+    {
+      priv->frame_drawn_serial = priv->window->sync_request_serial;
+      priv->window->needs_frame_drawn = FALSE;
+    }
+}
+
+void
+meta_window_actor_post_paint (MetaWindowActor *self)
+{
+  MetaWindowActorPrivate *priv = self->priv;
+
+  if (priv->frame_drawn_serial != 0)
+    {
+      MetaScreen  *screen  = priv->screen;
+      MetaDisplay *display = meta_screen_get_display (screen);
+      Display *xdisplay = meta_display_get_xdisplay (display);
+
+      XClientMessageEvent ev;
+
+      ev.type = ClientMessage;
+      ev.window = meta_window_get_xwindow (priv->window);
+      ev.message_type = display->atom_WM_PROTOCOLS;
+      ev.format = 32;
+      ev.data.l[0] = display->atom__NET_WM_FRAME_DRAWN;
+      ev.data.l[1] = 0; /* timestamp */
+      ev.data.l[2] = priv->frame_drawn_serial & G_GUINT64_CONSTANT(0xffffffff);
+      ev.data.l[3] = priv->frame_drawn_serial >> 32;
+      ev.data.l[4] = 0; /* vblank estimate */
+
+      meta_error_trap_push (display);
+      XSendEvent (xdisplay, ev.window, False, 0, (XEvent*) &ev);
+      meta_error_trap_pop (display);
+
+      priv->frame_drawn_serial = 0;
+    }
 }
 
 void

src/core/window-private.h

@@ -356,6 +356,10 @@ struct _MetaWindow
    * also handles application frames */
   guint extended_sync_request_counter : 1;
 
+  /* if TRUE, we still need to send a _NET_WM_FRAME_DRAWN message for the
+   * last update the sync request counter */
+  guint needs_frame_drawn : 1;
+
   /* Note: can be NULL */
   GSList *struts;
 

src/core/window.c

@@ -9493,6 +9493,9 @@ void
 meta_window_update_sync_request_counter (MetaWindow *window,
                                          gint64      new_counter_value)
 {
+  if (window->extended_sync_request_counter)
+    window->needs_frame_drawn = TRUE;
+
   window->sync_request_serial = new_counter_value;
   meta_compositor_set_updates_frozen (window->display->compositor, window,
                                       meta_window_updates_are_frozen (window));

src/meta/atomnames.h

@@ -174,6 +174,7 @@ item(_NET_WM_FULLSCREEN_MONITORS)
 item(_NET_WM_STATE_FOCUSED)
 item(_NET_WM_BYPASS_COMPOSITOR)
 item(_NET_WM_OPAQUE_REGION)
+item(_NET_WM_FRAME_DRAWN)
 
 #if 0
 /* We apparently never use: */