[mutter] Fix handling of dynamic updates to colors/font/etc.

[Owen Taylor <otaylor src gnome org>]

commit 4a8f7aa884ff531ceac0597aceade493dffe3c93
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Wed Mar 5 15:23:46 2014 -0500

    Fix handling of dynamic updates to colors/font/etc.
    
    Since the introduction of frame sync in GTK+, updates to titlebar font and
    colors haven't been working because GTK+ counts on the frame clock to
    do style updates, and the frame clock doesn't run for an unmapped
    GdkWindow. (It's possible that GtkStyleContext changes subsequent to
    the introduction of the frame clock were also needed to fully break
    things.)
    
    We actually need to map the MetaFrames GdkWindow and let the
    compositor code send out the frame sync messages in order to pick up
    style changes.
    
    Hopefully no bad side effects will occur from this - we make the window
    override-redirect, 1x1, and outside the bounds of the screen.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=725751

 src/ui/frames.c |   41 +++++++++++++++++------------------------
 src/ui/ui.c     |    9 ++++++---
 2 files changed, 23 insertions(+), 27 deletions(-)
---
diff --git a/src/ui/frames.c b/src/ui/frames.c
index d69224e..13633c9 100644
--- a/src/ui/frames.c
+++ b/src/ui/frames.c
@@ -44,8 +44,6 @@
 static void meta_frames_destroy       (GtkWidget       *object);
 static void meta_frames_finalize      (GObject         *object);
 static void meta_frames_style_updated (GtkWidget       *widget);
-static void meta_frames_map           (GtkWidget       *widget);
-static void meta_frames_unmap         (GtkWidget       *widget);
 
 static void meta_frames_update_prelit_control (MetaFrames      *frames,
                                                MetaUIFrame     *frame,
@@ -134,9 +132,6 @@ meta_frames_class_init (MetaFramesClass *class)
 
   widget_class->style_updated = meta_frames_style_updated;
 
-  widget_class->map = meta_frames_map;
-  widget_class->unmap = meta_frames_unmap;
-  
   widget_class->draw = meta_frames_draw;
   widget_class->destroy_event = meta_frames_destroy_event;  
   widget_class->button_press_event = meta_frames_button_press_event;
@@ -231,6 +226,7 @@ meta_frames_init (MetaFrames *frames)
 
   frames->style_variants = g_hash_table_new_full (g_str_hash, g_str_equal,
                                                   g_free, g_object_unref);
+
   update_style_contexts (frames);
 
   gtk_widget_set_double_buffered (GTK_WIDGET (frames), FALSE);
@@ -522,13 +518,26 @@ MetaFrames*
 meta_frames_new (int screen_number)
 {
   GdkScreen *screen;
+  MetaFrames *frames;
 
   screen = gdk_display_get_screen (gdk_display_get_default (),
                                    screen_number);
 
-  return g_object_new (META_TYPE_FRAMES,
-                       "screen", screen,
-                       NULL);  
+  frames = g_object_new (META_TYPE_FRAMES,
+                         "screen", screen,
+                         "type", GTK_WINDOW_POPUP,
+                         NULL);
+
+  /* Put the window at an arbitrary offscreen location; the one place
+   * it can't be is at -100x-100, since the meta_window_new() will
+   * mistake it for a window created via meta_create_offscreen_window()
+   * and ignore it, and we need this window to get frame-synchronization
+   * messages so that GTK+'s style change handling works.
+   */
+  gtk_window_move (GTK_WINDOW (frames), -200, -200);
+  gtk_window_resize (GTK_WINDOW (frames), 1, 1);
+
+  return frames;
 }
 
 /* In order to use a style with a window it has to be attached to that
@@ -635,22 +644,6 @@ meta_frames_unmanage_window (MetaFrames *frames,
     meta_warning ("Frame 0x%lx not managed, can't unmanage\n", xwindow);
 }
 
-static void
-meta_frames_map (GtkWidget *widget)
-{
-  /* We override the parent map function to a no-op because we don't
-   * want to actually show the GDK window. But GTK needs to think that
-   * the widget is mapped or it won't deliver the events we care about.
-   */
-  gtk_widget_set_mapped (widget, TRUE);
-}
-
-static void
-meta_frames_unmap (GtkWidget *widget)
-{
-  gtk_widget_set_mapped (widget, FALSE);
-}
-
 static MetaUIFrame*
 meta_frames_lookup_window (MetaFrames *frames,
                            Window      xwindow)
diff --git a/src/ui/ui.c b/src/ui/ui.c
index aa1d3bd..7d023dc 100644
--- a/src/ui/ui.c
+++ b/src/ui/ui.c
@@ -298,9 +298,12 @@ meta_ui_new (Display *xdisplay,
   g_assert (gdisplay == gdk_display_get_default ());
 
   ui->frames = meta_frames_new (XScreenNumberOfScreen (screen));
-  /* This does not actually show any widget. MetaFrames has been hacked so
-   * that showing it doesn't actually do anything. But we need the flags
-   * set for GTK to deliver events properly. */
+  /* GTK+ needs the frame-sync protocol to work in order to properly
+   * handle style changes. This means that the dummy widget we create
+   * to get the style for title bars actually needs to be mapped
+   * and fully tracked as a MetaWindow. Horrible, but mostly harmless -
+   * the window is a 1x1 overide redirect window positioned offscreen.
+   */
   gtk_widget_show (GTK_WIDGET (ui->frames));
 
   g_object_set_data (G_OBJECT (gdisplay), "meta-ui", ui);