Swiping the home screen causes the WindowManagerService to do
a bunch of work to keep the wallpapers in sync. First, it lays out
and places all windows. Also, it notifies the SystemUI process that
the wallpaper position has changed.
The layout/place operation is too much work - we only need to set
the position values for the wallpaper, not relayout the whole system.
The notification mechanism must exist, but should be optional. Most
wallpapers don't care (especially static ImageWallpapers). So we'll
give them a new API (WallpaperService.Engine.setWantsOffsets()) to
allow wallpapers to opt out of this process and avoid the performance
overhead.
Change-Id: I66c38375438937f14f6f5550565b28eb204b1e06
Take care of updating from old component name, and don't let this happen
again.
Also tweak how we switch between static wallpapers to avoid introducing
a 4MB allocation in the system UI process when this happens -- we now
stop the current wallpaper service and start a new one, so we get a
brand new surface that we can draw only one time in to.
Change-Id: I6fc8a42b8a46bba79759bd68fb7d0684b5d897b7
Nice to not load 4MB bitmaps in the system process.
Also, hey, with how we are now scrolling the surface instead of
the bitmap, there is no reason to keep that 4MB bitmap loaded in
to memory. So don't.
Unfortunately it looks like for some reason the VM is still
holding on to the bitmap. I'll need to figure out why. Later.
Change-Id: Ib3503756144502fc5c8d5e294248c2417c4fe8c8
