Created attachment 246115 [details] Snap Point Example Using the attached test document, I sometimes find WebKit fighting with my scroll motion if a snap point animation starts, and I then attempt to start a manual scroll. It seems like the animation is not being turned off when new user input is encountered.
Manual Test: 1. Load the attached snap point example. 2. Partially scroll a view, so that the snap scroll kicks in and WebKit tries to slide the view back to the specified snap point. 3. While the snap point animation is running, begin a new scroll gesture to scroll the view. Result: Currently, you get jittering as the snap animation fights with the scrolling gesture.
<rdar://problem/19733626>
This problem was corrected during other snap-point work. The underlying problem was that certain wheel event states were not properly handled by the scroll snap animator logic. This caused the snap animation to continue to run even when the user began certain kinds of wheel gestures. This is now resolved.