Calling requestLayout() during a layout pass is inadvisable, but
happens often enough in applications (especially when it occurs in
very indirect means that the application may not easily be able to
control) that we need to handle the situation without breaking. In particular,
applications that have run across this problem have had artifacts which are
difficult to debug (like things just not showing up on the screen) and
also difficult to fix. One of the side-effects of the problem is that it
leaves the view hiearchy in an unpredictable state where some views have
requested layout and are waiting to be layed out while the root view has
not received those requests, so it is never calling layout on those views.
The fix is to try to do the 'right' thing, while avoiding getting into
an inifinite loop (which could result from calling layout, which calls requestLayout(),
which causes another layout, which ...). The solution is two-tier: we handle
all requests that happen during layout by delaying them until after the current
layout is done. We then process those requests and call layout again.
If we receive more requests during that second layout, we post them to the
next frame, to allow us to finish the current one.
Issue #7155974 handle requestLayout() during layout more robustly
Change-Id: I9d13c405be28a19c86add22210e69817ddddaf8b
971405797f