defaultabstracttree.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.extensions.markup.html.tree;

import java.io.Serializable;

import javax.swing.tree.TreeModel;
import javax.swing.tree.TreeNode;

import org.apache.wicket.Component;
import org.apache.wicket.IClusterable;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.RequestCycle;
import org.apache.wicket.ResourceReference;
import org.apache.wicket.Response;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.markup.html.AjaxFallbackLink;
import org.apache.wicket.ajax.markup.html.AjaxLink;
import org.apache.wicket.behavior.HeaderContributor;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.markup.html.WebMarkupContainer;
import org.apache.wicket.markup.html.link.Link;
import org.apache.wicket.markup.html.tree.AbstractTree;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.Model;
import org.apache.wicket.util.lang.EnumeratedType;


/**
 * Tree class that contains convenient functions related to presentation of the tree, which includes
 * junction link, tree item selection link, spacers (with lines) and default tree item and folder
 * icons.
 * <p>
 * The class itself adds no component to tree items. If you use this class directly, you have to
 * implement populateTreeItem() on your own. If you want to use an existing (complete) tree class,
 * use {@link Tree}
 * <p>
 * This class allows you to choose between 3 types of links.
 * {@link DefaultAbstractTree#setLinkType(org.apache.wicket.extensions.markup.html.tree.DefaultAbstractTree.LinkType)}
 * 
 * @author Matej Knopp
 */
public abstract class DefaultAbstractTree extends AbstractTree
{
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	/**
	 * The type of junction links and node selection links.
	 * <dl>
	 * <dt>Regular link</dt>
	 * <dd>Non-ajax link, always refreshes the whole page. Works with javascript disabled.</dd>
	 * <dt>Ajax link</dt>
	 * <dd>Links that supports partial updates. Doesn't work with javascript disabled</dd>
	 * <dt>Ajax fallback link</dt>
	 * <dd>Link that supports partial updates. With javascript disabled acts like regular link. The
	 * drawback is that generated url (thus the entire html) is larger then using the other two</dd>
	 * </dl>
	 */
	public static final class LinkType extends EnumeratedType
	{

		/** partial updates with no fallback. */
		public static final LinkType AJAX = new LinkType("AJAX");

		/**
		 * partial updates that falls back to a regular link in case the client does not support
		 * javascript.
		 */
		public static final LinkType AJAX_FALLBACK = new LinkType("AJAX_FALLBACK");

		/**
		 * non-ajax version that always re-renders the whole page.
		 */
		public static final LinkType REGULAR = new LinkType("REGULAR");

		private static final long serialVersionUID = 1L;

		/**
		 * Construct.
		 * 
		 * @param name
		 */
		public LinkType(String name)
		{
			super(name);
		}
	}

	/**
	 * Helper class for calling an action from a link.
	 * 
	 * @author Matej Knopp
	 */
	protected interface ILinkCallback extends IClusterable
	{
		/**
		 * Called when the click is executed.
		 * 
		 * @param target
		 *            The ajax request target
		 */
		void onClick(AjaxRequestTarget target);
	}

	/**
	 * Reference to the css file.
	 */
	private static final ResourceReference CSS = new ResourceReference(DefaultAbstractTree.class,
		"res/tree.css");

	/** Reference to the icon of closed tree folder */
	private static final ResourceReference FOLDER_CLOSED = new ResourceReference(
		DefaultAbstractTree.class, "res/folder-closed.gif");

	/** Reference to the icon of open tree folder */
	private static final ResourceReference FOLDER_OPEN = new ResourceReference(
		DefaultAbstractTree.class, "res/folder-open.gif");

	/** Reference to the icon of tree item (not a folder) */
	private static final ResourceReference ITEM = new ResourceReference(DefaultAbstractTree.class,
		"res/item.gif");

	/** The link type, default is {@link LinkType#AJAX ajax}. */
	private LinkType linkType = LinkType.AJAX;

	/**
	 * Tree constructor.
	 * 
	 * @param id
	 *            The component id
	 */
	public DefaultAbstractTree(String id)
	{
		super(id);
		init();
	}

	/**
	 * Tree constructor.
	 * 
	 * @param id
	 *            The component id
	 * @param model
	 *            The tree model
	 */
	public DefaultAbstractTree(String id, IModel model)
	{
		super(id, model);
		init();
	};

	/**
	 * Tree constructor.
	 * 
	 * @param id
	 *            The component id
	 * @param model
	 *            The tree model
	 */
	public DefaultAbstractTree(String id, TreeModel model)
	{
		super(id, new Model((Serializable)model));
		init();
	}

	/**
	 * Returns the current type of links on tree items.
	 * 
	 * @return The link type
	 */
	public LinkType getLinkType()
	{
		return linkType;
	}

	/**
	 * Sets the type of links on tree items. After the link type is changed, the whole tree is
	 * rebuild and re-rendered.
	 * 
	 * @param linkType
	 *            type of links
	 */
	public void setLinkType(LinkType linkType)
	{
		if (this.linkType != linkType)
		{
			this.linkType = linkType;
			invalidateAll();
		}
	}

	/**
	 * Returns the resource reference of default stylesheet.
	 * 
	 * @return The package resource reference
	 */
	protected ResourceReference getCSS()
	{
		return CSS;
	}

	/**
	 * Returns the resource reference of default closed tree folder.
	 * 
	 * @return The package resource reference
	 */
	protected ResourceReference getFolderClosed()
	{
		return FOLDER_CLOSED;
	}

	/**
	 * Returns the resource reference of default open tree folder.
	 * 
	 * @return The package resource reference
	 */
	protected ResourceReference getFolderOpen()
	{
		return FOLDER_OPEN;
	};

	/**
	 * Returns the resource reference of default tree item (not folder).
	 * 
	 * @return The package resource reference
	 */
	protected ResourceReference getItem()
	{
		return ITEM;
	}

	/**
	 * Returns the resource reference for icon of specified tree node.
	 * 
	 * @param node
	 *            The node
	 * @return The package resource reference
	 */
	protected ResourceReference getNodeIcon(TreeNode node)
	{
		if (node.isLeaf() == true)
		{
			return getItem();
		}
		else
		{
			if (isNodeExpanded(node))
			{
				return getFolderOpen();
			}
			else
			{
				return getFolderClosed();
			}
		}
	}

	/**
	 * Creates the indentation element. This element should be placed as first element in the tree
	 * item markup to ensure proper indentation of the tree item. This implementation also takes
	 * care of lines that connect nodes.
	 * 
	 * @param parent
	 *            The component parent
	 * @param id
	 *            The component id
	 * @param node
	 *            The tree node for which to create the indentation element
	 * @param level
	 *            The current level
	 * @return The indentation component
	 */
	protected Component newIndentation(MarkupContainer parent, String id, final TreeNode node,
		final int level)
	{
		WebMarkupContainer result = new WebMarkupContainer(id)
		{
			private static final long serialVersionUID = 1L;

			/**
			 * @see org.apache.wicket.MarkupContainer#onComponentTagBody(org.apache.wicket.markup.MarkupStream,
			 *      org.apache.wicket.markup.ComponentTag)
			 */
			protected void onComponentTagBody(MarkupStream markupStream, ComponentTag openTag)
			{
				Response response = RequestCycle.get().getResponse();
				TreeNode parent = node.getParent();

				CharSequence urls[] = new CharSequence[level];
				for (int i = 0; i < level; ++i)
				{
					if (isNodeLast(parent))
					{
						urls[i] = "indent-blank";