- Reverting changes to the existing thumbnail transition to prevent breaking applications
that currently depend on that transition. As a result, we need to create a new, hidden,
aspect-scaled thumbnail transition, and instead use that thumbnail to animate the
recents header so that we don't have to wait to do that inside the Recents activity.
In order for this to work, we also have to ensure that the thumbnail surface destruction
is synchronized with the application that is currently closing (when going down to
recents) or opening (when coming back up). The current thumbnail is destroyed when the
animation ends, but that can be at least 1 frame before the surface for the animating
window is destroyed. We change this by deferring destruction of this thumbnail window
to the animation that is being closed.
Especially on the way up, not having to wait for us to hide the header before doing the
transition up can save us the duration of that first animation (> 100ms).
- Other optimizations:
* No longer creating a new stack view on each transition to calculate the target rect
* Removing unnecessary call to get the thumbnail when transitioning up/down (the actual
window does its own animation.
* We reduced numerous system calls per task by adding a flag to ignore home-stack tasks
and caching the activity label and icon (and task description icon). These caches
follow the same eviction schemes as the thumbnail and icon cache.
- Also tweaked the touch slop for the nav bar swiping gesture to prevent conflicting with
tapping on home (Bug 17109581)
Change-Id: Ica697aad788051a9203edd9351c583e1cb038a71
a4ccb86ddc