[gtk/make-claiming-button-release-work] gestures: Make claiming button release work

[Matthias Clasen <matthiasc src gnome org>]

commit 53dddf163de2b16d6140a47240e07925a529639d
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Sep 14 08:35:44 2020 -0400

    gestures: Make claiming button release work
    
    When claiming a sequence in a gesture signal handler,
    the expected result is that GtkGesture::handle-event
    returns TRUE, causing the event to not be propagated
    further.
    
    This doesn't work for button release events, since
    gtk_gesture_handle_event does the following:
      add point
      emit ::update
      remove point
      check claimed status
    The ::update signal is where the application code
    claims the sequence. But removing the point purges
    the sequence from the gestures memory, so checking
    the claimed status returns FALSE.
    
    This patch fixes things to behave as expected, by
    checking the claimed status before removing the point.

 gtk/gtkgesture.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtkgesture.c b/gtk/gtkgesture.c
index 1e425869b3..f0bb28421a 100644
--- a/gtk/gtkgesture.c
+++ b/gtk/gtkgesture.c
@@ -660,7 +660,7 @@ gtk_gesture_handle_event (GtkEventController *controller,
            (event_type == GDK_TOUCHPAD_SWIPE && phase == GDK_TOUCHPAD_GESTURE_PHASE_END) ||
            (event_type == GDK_TOUCHPAD_PINCH && phase == GDK_TOUCHPAD_GESTURE_PHASE_END))
     {
-      gboolean was_claimed;
+      gboolean was_claimed = FALSE;
 
       if (_gtk_gesture_update_point (gesture, event, target, x, y, FALSE))
         {
@@ -668,12 +668,12 @@ gtk_gesture_handle_event (GtkEventController *controller,
               _gtk_gesture_check_recognized (gesture, sequence))
             g_signal_emit (gesture, signals[UPDATE], 0, sequence);
 
+          was_claimed =
+            gtk_gesture_get_sequence_state (gesture, sequence) == GTK_EVENT_SEQUENCE_CLAIMED;
+
           _gtk_gesture_remove_point (gesture, event);
         }
 
-      was_claimed =
-        gtk_gesture_get_sequence_state (gesture, sequence) == GTK_EVENT_SEQUENCE_CLAIMED;
-
       return was_claimed && was_recognized;
     }
   else if (event_type == GDK_MOTION_NOTIFY ||