GitLab

When the currentState is Peeked and a transition starts, if the user
switched direction (from Revealed to Hidden and from Hidden to Revealed
again), the layout switcher's collection view would start a new
transition when one already existed:
`'NSInternalInconsistencyException', reason: 'the collection is already
in the middle of an interactive transition'`

Create a bool property |layoutBeingInteractedWith|, which is YES when
the user is scrubbing a layout transition. The layout transition
progress is only updated if this property is YES.

Create a bool property |gesturesEnabled|, which is set to NO when a pan
gesture ends and set to YES when a gesture begins and
|layoutInTransition| is NO. This is to prevent a gesture from being
recognised if it starts while the layout is already transitioning but
changes or ends after the layout transition is over. If that were to
happen, the viewRevealngVerticalPanHandler would fail to notify the
animatees that a view reveal would take place.

Bug: 1130037, 1127604
Change-Id: Ifc5eb40843673ab3ce663ed23a3b2f8cf18d9564
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2421741Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Roberto Moura <mouraroberto@google.com>
Cr-Commit-Position: refs/heads/master@{#812189}