/*
* Copyright 2007 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.user.client.ui;
import java.util.Iterator;
/**
* A widget that implements this interface contains
* {@link com.google.gwt.user.client.ui.Widget widgets} and can enumerate them.
*/
public interface HasWidgets extends Iterable<Widget> {
/**
* Extends this interface with convenience methods to handle {@link IsWidget}.
*/
interface ForIsWidget extends HasWidgets {
void add(IsWidget w);
boolean remove(IsWidget w);
}
/**
* Adds a child widget.
*
* @param w the widget to be added
* @throws UnsupportedOperationException if this method is not supported (most
* often this means that a specific overload must be called)
*/
void add(Widget w);
/**
* Removes all child widgets.
*/
void clear();
/**
* Gets an iterator for the contained widgets. This iterator is required to
* implement {@link Iterator#remove()}.
*/
Iterator<Widget> iterator();
/**
* Removes a child widget.
*
* @param w the widget to be removed
* @return <code>true</code> if the widget was present
*/
boolean remove(Widget w);
}