swipe-action: Prepare for multifinger swipes

Its ::gesture-end implementation used to check the press/release
coordinates for the first touchpoint. On multifinger swipes, we
can receive this vfunc called due to other touch sequence going
first, so we'd get 0/0 as the release coordinates for this still
active sequence, resulting in bogus directions.

Instead, check the last event coordinates, that will be always
correct regardless of whether the touchpoint 0 finished yet or
not.

https://bugzilla.gnome.org/show_bug.cgi?id=749739

1 files changed, 6 insertions, 3 deletions

diff --git a/clutter/clutter-swipe-action.c b/clutter/clutter-swipe-action.c
index 452a5a020..38e183085 100644
--- a/clutter/clutter-swipe-action.c
+++ b/clutter/clutter-swipe-action.c
@@ -145,14 +145,17 @@ gesture_end (ClutterGestureAction *action,
   gfloat release_x, release_y;
   ClutterSwipeDirection direction = 0;
   gboolean can_emit_swipe;
+  const ClutterEvent *last_event;
 
   clutter_gesture_action_get_press_coords (action,
                                            0,
                                            &press_x, &press_y);
 
-  clutter_gesture_action_get_release_coords (action,
-                                             0,
-                                             &release_x, &release_y);
+  /* Check the last event instead of get_release_coords(), this
+   * might not be the sequence that finished on multi-finger swipes.
+   */
+  last_event = clutter_gesture_action_get_last_event (action, 0);
+  clutter_event_get_coords (last_event, &release_x, &release_y);
 
   if (release_x - press_x > priv->distance_y)
     direction |= CLUTTER_SWIPE_DIRECTION_RIGHT;