shrink method
Shrinks the appbar to its shrinked state, optionally with animation.
If useAnimate is true (default), the shrinking will be animated.
Otherwise, the app bar will snap to its shrunk size immediately.
Implementation
void shrink({bool useAnimate = true}) {
if (useAnimate) {
performAlignment(AppBarAlignmentCommand.shrink);
return;
}
setPixels(shrinkedPixels);
}