Handle recursion from motion event handlers

If a motion event handler (or other handler running from the flush-events
phase of the frame clock) recursed the main loop then flushing wouldn't
complete until after the recursed main loop returned, and various aspects
of the state would get out of sync.

To fix this, change flushing of the event queue to simply mark events as
ready to flush, and let normal event delivery handle the rest.

https://bugzilla.gnome.org/show_bug.cgi?id=705176

1 files changed, 8 insertions, 1 deletions

diff --git a/gdk/gdkinternals.h b/gdk/gdkinternals.h
index b2456662ec..bebdec03b7 100644
--- a/gdk/gdkinternals.h
+++ b/gdk/gdkinternals.h
@@ -156,7 +156,13 @@ typedef enum
    * 1) touch events emulating pointer events
    * 2) pointer events being emulated by a touch sequence.
    */
-  GDK_EVENT_POINTER_EMULATED = 1 << 1
+  GDK_EVENT_POINTER_EMULATED = 1 << 1,
+
+  /* When we are ready to draw a frame, we pause event delivery,
+   * mark all events in the queue with this flag, and deliver
+   * only those events until we finish the frame.
+   */
+  GDK_EVENT_FLUSHED = 1 << 2
 } GdkEventFlags;
 
 struct _GdkEventPrivate
@@ -305,6 +311,7 @@ GList* _gdk_event_queue_insert_before(GdkDisplay *display,
                                       GdkEvent   *event);
 
 void    _gdk_event_queue_handle_motion_compression (GdkDisplay *display);
+void    _gdk_event_queue_flush                     (GdkDisplay       *display);
 
 void   _gdk_event_button_generate    (GdkDisplay *display,
                                       GdkEvent   *event);