public interface ProvidesResize
RequiresResize.onResize() on its children whenever their size may
have changed.
With limited exceptions (such as RootLayoutPanel), widgets that
implement this interface will also implement RequiresResize. A typical
widget will implement RequiresResize.onResize() like this:
public void onResize() {
for (Widget child : getChildren()) {
if (child instanceof RequiresResize) {
((RequiresResize) child).onResize();
}
}
}