Animation bug

[jaredsinclair]

The focus animations when crossing a boundary that triggers a jump() are incorrect. For example, given a collection view index set like:

Collection View:    0 1 2 3 4 5 6 7 8 9
Underlying Indexes: - - - 0 1 2 3 - - -

When moving focus from collection view index 4 towards collection view index 3, the jump that is triggered causes the cells involved in the jump to focus/unfocus without the correct animation durations. The exact bug surfaces differently depending on how focus effects are applied and how the collection view decides to dequeue cells. Sometimes the focused cell from before the jump is dequeued and reused at a different index path, then unfocuses with an animation after the jump. It appears to the user like a cell that should not have been focused in the first place.

60 fps movie capture direct over USB using Quick Time can help pinpoint the animation problems.