wicketdnd.util.MarkupIdVisitor.java Source code

Introduction

Here is the source code for wicketdnd.util.MarkupIdVisitor.java

Source

/*
 * 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;
    }
}