performRebuild method
Cause the widget to update itself.
Called by rebuild after the appropriate checks have been made.
The base implementation only clears the dirty flag.
Implementation
@override
void performRebuild() {
// This gets called if markNeedsBuild() is called on us.
// That might happen if, e.g., our delegate inflates InheritedWidgets.
renderObject.markNeedsLayout();
super
.performRebuild(); // Calls widget.updateRenderObject (a no-op in this case).
}