Provide a way to schedule a callback for immediately after the current
frame has been sent to the GPU thread. This is useful for times where
you want to immediately schedule yourself for another build or layout
because, for instance, you just displayed frame zero of an animation and
you want to use the metrics from that layout to set up the actual
animation to begin immediately, such that the very next frame is frame 1.
Focus.at() and company should be on Focus, not FocusState.
_notifyDescendants() was using the wrong runtimeType.
Let InheritedWidget update the descendants during build.
When you setState() during build, assert that you're not
markNeedsBuild()ing someone who isn't a descendant.
Typo in Widget.toString().
This patch makes a number of changes:
1) buildDirtyComponents now prevents all calls to setState, not just those
higher in the tree. This change is necessary for consistency with
MixedViewport and HomogeneousViewport because those widgets already build
subwidgets with that restriction. If the "normal" build didn't enforce that
rule, then some widgets would break when put inside a mixed or homogeneous
viewport.
2) We now notify global key listeners in a microtask after beginFrame. That
means setState is legal in these callbacks and that we'll produce another
frame if someone calls setState in such a callback.
