/* * Copyright 2009 Sven Meier * * 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 wicketdnd.util; import org.apache.wicket.Component; import org.apache.wicket.MarkupContainer; import org.apache.wicket.protocol.http.PageExpiredException; import org.apache.wicket.util.visit.IVisit; import org.apache.wicket.util.visit.IVisitor; /** * Find a child component by it's markup id. * * @author Sven Meier */ public class MarkupIdVisitor implements IVisitor<Component,Component> { private final String id; public MarkupIdVisitor(String id) { if (id == null) { throw new IllegalArgumentException("id must not be null"); } this.id = id; } public void component(Component component, final IVisit<Component> visit) { if (id.equals(component.getMarkupId(false))) { visit.stop(component); } } /** * Get the given container's descendent by markup id. * * @param container * container to find descendent of * @param id * markup id * @return component * @throws PageExpiredException * if no descendent has the given markup id */ public static Component getComponent(MarkupContainer container, String id) { if (id.equals(container.getMarkupId(false))) { return container; } Component component = container .visitChildren(new MarkupIdVisitor(id)); if (component == null) { throw new PageExpiredException("No component with markup id " + id); } return component; } }