screen-cast/window: Use window actor damaged signal instead of paint

We are really more interested in when a window is damaged, rather than
when it's painted, for screen casting windows. This also has the benefit
of not listening on the "paint" signal of the actor, meaning it'll open
doors for hacks currently necessary for taking a screenshot of a window
consisting of multiple surfaces.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/752

1 files changed, 11 insertions, 34 deletions

diff --git a/src/backends/meta-screen-cast-window-stream-src.c b/src/backends/meta-screen-cast-window-stream-src.c
index dbf330420..c31830b03 100644
--- a/src/backends/meta-screen-cast-window-stream-src.c
+++ b/src/backends/meta-screen-cast-window-stream-src.c
@@ -34,13 +34,11 @@ struct _MetaScreenCastWindowStreamSrc
 
   MetaScreenCastWindow *screen_cast_window;
 
-  unsigned long screen_cast_window_before_paint_handler_id;
-  unsigned long screen_cast_window_after_paint_handler_id;
+  unsigned long screen_cast_window_damaged_handler_id;
   unsigned long screen_cast_window_destroyed_handler_id;
   unsigned long cursor_moved_handler_id;
   unsigned long cursor_changed_handler_id;
 
-  gboolean actor_was_dirty;
   gboolean cursor_bitmap_invalid;
 };
 
@@ -255,15 +253,10 @@ meta_screen_cast_window_stream_src_stop (MetaScreenCastWindowStreamSrc *window_s
   if (!window_src->screen_cast_window)
     return;
 
-  if (window_src->screen_cast_window_before_paint_handler_id)
+  if (window_src->screen_cast_window_damaged_handler_id)
     g_signal_handler_disconnect (window_src->screen_cast_window,
-                                 window_src->screen_cast_window_before_paint_handler_id);
-  window_src->screen_cast_window_before_paint_handler_id = 0;
-
-  if (window_src->screen_cast_window_after_paint_handler_id)
-    g_signal_handler_disconnect (window_src->screen_cast_window,
-                                 window_src->screen_cast_window_after_paint_handler_id);
-  window_src->screen_cast_window_after_paint_handler_id = 0;
+                                 window_src->screen_cast_window_damaged_handler_id);
+  window_src->screen_cast_window_damaged_handler_id = 0;
 
   if (window_src->screen_cast_window_destroyed_handler_id)
     g_signal_handler_disconnect (window_src->screen_cast_window,
@@ -282,23 +275,12 @@ meta_screen_cast_window_stream_src_stop (MetaScreenCastWindowStreamSrc *window_s
 }
 
 static void
-screen_cast_window_before_paint (MetaScreenCastWindow          *screen_cast_window,
-                                 MetaScreenCastWindowStreamSrc *window_src)
-{
-  window_src->actor_was_dirty =
-    meta_screen_cast_window_has_damage (screen_cast_window);
-}
-
-static void
-screen_cast_window_after_paint (MetaWindowActor               *actor,
-                                MetaScreenCastWindowStreamSrc *window_src)
+screen_cast_window_damaged (MetaWindowActor               *actor,
+                            MetaScreenCastWindowStreamSrc *window_src)
 {
-  if (window_src->actor_was_dirty)
-    {
-      MetaScreenCastStreamSrc *src = META_SCREEN_CAST_STREAM_SRC (window_src);
+  MetaScreenCastStreamSrc *src = META_SCREEN_CAST_STREAM_SRC (window_src);
 
-      meta_screen_cast_stream_src_maybe_record_frame (src);
-    }
+  meta_screen_cast_stream_src_maybe_record_frame (src);
 }
 
 static void
@@ -378,16 +360,11 @@ meta_screen_cast_window_stream_src_enable (MetaScreenCastStreamSrc *src)
 
   window_src->screen_cast_window = META_SCREEN_CAST_WINDOW (window_actor);
 
-  window_src->screen_cast_window_before_paint_handler_id =
+  window_src->screen_cast_window_damaged_handler_id =
     g_signal_connect (window_src->screen_cast_window,
-                      "paint",
-                      G_CALLBACK (screen_cast_window_before_paint),
+                      "damaged",
+                      G_CALLBACK (screen_cast_window_damaged),
                       window_src);
-  window_src->screen_cast_window_after_paint_handler_id =
-    g_signal_connect_after (window_src->screen_cast_window,
-                            "paint",
-                            G_CALLBACK (screen_cast_window_after_paint),
-                            window_src);
 
   window_src->screen_cast_window_destroyed_handler_id =
     g_signal_connect (window_src->screen_cast_window,