panel.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.markup.html.panel;

import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupException;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.markup.html.WebMarkupContainerWithAssociatedMarkup;
import org.apache.wicket.markup.html.internal.HtmlHeaderContainer;
import org.apache.wicket.markup.parser.XmlTag;
import org.apache.wicket.markup.parser.filter.WicketTagIdentifier;
import org.apache.wicket.model.IModel;

/**
 * A panel is a reusable component that holds markup and other components.
 * <p>
 * Whereas WebMarkupContainer is an inline container like
 * 
 * <pre>
 *  ...
 *  &lt;span wicket:id=&quot;xxx&quot;&gt;
 *    &lt;span wicket:id=&quot;mylabel&quot;&gt;My label&lt;/span&gt;
 *    ....
 *  &lt;/span&gt;
 *  ...
 * </pre>
 * 
 * a Panel has its own associated markup file and the container content is taken from that file,
 * like:
 * 
 * <pre>
 *  &lt;span wicket:id=&quot;mypanel&quot;/&gt;
 * 
 *  TestPanel.html
 *  &lt;wicket:panel&gt;
 *    &lt;span wicket:id=&quot;mylabel&quot;&gt;My label&lt;/span&gt;
 *    ....
 *  &lt;/wicket:panel&gt;
 * </pre>
 * 
 * @author Jonathan Locke
 * @author Juergen Donnerstag
 */
public class Panel extends WebMarkupContainerWithAssociatedMarkup
{
	private static final long serialVersionUID = 1L;

	static
	{
		// register "wicket:panel"
		WicketTagIdentifier.registerWellKnownTagName("panel");
	}

	/** If if tag was an open-close tag */
	private boolean wasOpenCloseTag = false;

	/**
	 * @see org.apache.wicket.Component#Component(String)
	 */
	public Panel(final String id)
	{
		super(id);
	}

	/**
	 * @see org.apache.wicket.Component#Component(String, IModel)
	 */
	public Panel(final String id, final IModel model)
	{
		super(id, model);
	}

	/**
	 * 
	 * @see org.apache.wicket.Component#onComponentTag(org.apache.wicket.markup.ComponentTag)
	 */
	protected void onComponentTag(final ComponentTag tag)
	{
		if (tag.isOpenClose())
		{
			wasOpenCloseTag = true;

			// Convert <span wicket:id="myPanel" /> into
			// <span wicket:id="myPanel">...</span>
			tag.setType(XmlTag.OPEN);
		}
		super.onComponentTag(tag);
	}

	/**
	 * 
	 * @see org.apache.wicket.Component#onComponentTagBody(org.apache.wicket.markup.MarkupStream,
	 *      org.apache.wicket.markup.ComponentTag)
	 */
	protected void onComponentTagBody(final MarkupStream markupStream, final ComponentTag openTag)
	{
		// Render the associated markup
		renderAssociatedMarkup("panel",
				"Markup for a panel component has to contain part '<wicket:panel>'");

		if (wasOpenCloseTag == false)
		{
			// Skip any raw markup in the body
			markupStream.skipRawMarkup();
			if (markupStream.get().closes(openTag) == false)
			{
				throw new MarkupException("close tag not found for tag: " + openTag.toString() +
						". Component: " + this.toString());
			}
		}
	}

	/**
	 * Check the associated markup file for a wicket header tag
	 * 
	 * @see org.apache.wicket.Component#renderHead(org.apache.wicket.markup.html.internal.HtmlHeaderContainer)
	 */
	public void renderHead(HtmlHeaderContainer container)
	{
		renderHeadFromAssociatedMarkupFile(container);
		super.renderHead(container);
	}
}