performLayout method
override
This method has been overridden to eventually measure the size of new resizing intervals and
to eventually adjust the scroll offset.
If required by AnimatedSliverList.updateScrollableWhenResizing attribute, calls the
_notifyScrollable
method to update the scroll listeners when a resizing inerval is animating.
Implementation
@override
void performLayout() {
_inPerformLayout = true;
var resizing = false;
final childConstraints = constraints.asBoxConstraints();
for (var i in _intervals) {
if (i.isInResizingState) {
resizing = true;
if (i._fromSize == null || i._toSize == null) {
_measureIntervalSize(i, childConstraints);
}
}
}
super.performLayout();
_inPerformLayout = false;
childManager._adjustScrollOffset();
if (resizing && widget.updateScrollableWhenResizing) _notifyScrollable();
}