componentrequesttarget.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.wicket.request.target.component;

import org.apache.wicket.Component;
import org.apache.wicket.Page;
import org.apache.wicket.RequestCycle;

/**
 * Default implementation of
 * {@link org.apache.wicket.request.target.component.IComponentRequestTarget}. Target that denotes
 * a single component instance.
 * 
 * @author Eelco Hillenius
 */
public class ComponentRequestTarget implements IComponentRequestTarget
{
	/** the component instance. */
	private final Component component;

	/**
	 * Construct.
	 * 
	 * @param component
	 *            the component instance
	 */
	public ComponentRequestTarget(final Component component)
	{
		if (component == null)
		{
			throw new IllegalArgumentException("Argument 'component' must be not null");
		}

		this.component = component;
	}

	/**
	 * @see org.apache.wicket.IRequestTarget#respond(org.apache.wicket.RequestCycle)
	 */
	public void respond(final RequestCycle requestCycle)
	{
		// Initialize temporary variables
		Page page = component.getPage();
		if (page != null)
		{
			page.startComponentRender(component);
		}

		// Let component render itself
		if (component instanceof Page)
		{
			// Use the default Page request target, if component is a Page
			new PageRequestTarget((Page)component).respond(requestCycle);
		}
		else
		{
			// Render the component
			try
			{
				// Render the component
				component.renderComponent();
			}
			finally
			{
				component.getPage().detach();
			}
		}

		if (page != null)
		{
			page.endComponentRender(component);
		}
	}

	/**
	 * @see org.apache.wicket.request.target.component.IComponentRequestTarget#getComponent()
	 */
	public final Component getComponent()
	{
		return component;
	}

	/**
	 * @see org.apache.wicket.IRequestTarget#detach(org.apache.wicket.RequestCycle)
	 */
	public void detach(final RequestCycle requestCycle)
	{
	}

	/**
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals(final Object obj)
	{
		if (obj instanceof ComponentRequestTarget)
		{
			ComponentRequestTarget that = (ComponentRequestTarget)obj;
			return component.equals(that.component);
		}
		return false;
	}

	/**
	 * @see java.lang.Object#hashCode()
	 */
	public int hashCode()
	{
		int result = "ComponentRequestTarget".hashCode();
		result += component.hashCode();
		return 17 * result;
	}

	/**
	 * @see java.lang.Object#toString()
	 */
	public String toString()
	{
		return "[ComponentRequestTarget@" + hashCode() + " " + component + "]";
	}
}