This tag interface specifies that the implementing widget will call {@link RequiresResize#onResize()} on its children whenever their size may have changed.

With limited exceptions (such as {@link RootLayoutPanel}), widgets that implement this interface will also implement {@link RequiresResize}. A typical widget will implement {@link RequiresResize#onResize()} like this: public void onResize() { for (Widget child : getChildren()) { if (child instanceof RequiresResize) { ((RequiresResize) child).onResize(); } } }

abstract class ProvidesResize {

}