ajaxpagingnavigationincrementlink.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.ajax.markup.html.navigation.paging;

import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.markup.html.IAjaxLink;
import org.apache.wicket.markup.html.navigation.paging.IPageable;
import org.apache.wicket.markup.html.navigation.paging.PagingNavigationIncrementLink;

/**
 * An incremental Ajaxian link to a page of a PageableListView. Assuming your list view navigation
 * looks like
 * 
 * <pre>
 *               
 *              	 [first / &lt;&lt; / &lt;] 1 | 2 | 3 [&gt; / &gt;&gt; /last]
 *              	
 * </pre>
 * 
 * <p>
 * and "&lt;" meaning the previous and "&lt;&lt;" goto the "current page - 5", than it is this kind
 * of incremental page links which can easily be created.
 * 
 * This link will update the pageable and itself or the navigator the link is part of using Ajax
 * techniques, or perform a full refresh when ajax is not available.
 * 
 * @since 1.2
 * 
 * @author Martijn Dashorst
 */
public class AjaxPagingNavigationIncrementLink extends PagingNavigationIncrementLink
		implements
			IAjaxLink
{
	private static final long serialVersionUID = 1L;

	/**
	 * Constructor.
	 * 
	 * @param id
	 *            See Component
	 * @param pageable
	 *            The pageable component the page links are referring to
	 * @param increment
	 *            increment by
	 */
	public AjaxPagingNavigationIncrementLink(final String id, final IPageable pageable,
			final int increment)
	{
		super(id, pageable, increment);
		add(new AjaxPagingNavigationBehavior(this, pageable, "onclick"));

		setOutputMarkupId(true);
	}

	/**
	 * Returns the javascript event handler for this component. This function is used to decorate
	 * the generated javascript handler.
	 * <p>
	 * NOTE: It is recommended that you only prepend additional javascript to the default handler
	 * because the default handler uses the return func() format so any appended javascript will not
	 * be evaluated by default.
	 * 
	 * @param defaultHandler
	 *            default javascript event handler generated by this link
	 * @return javascript event handler for this link
	 */
	protected String getEventHandler(String defaultHandler)
	{
		return defaultHandler;
	}


	/**
	 * Fallback event listener, will redisplay the current page.
	 * 
	 * @see org.apache.wicket.markup.html.link.Link#onClick()
	 */
	public void onClick()
	{
		onClick(null);

		// We do not need to redirect
		setRedirect(false);

		// Return the the current page.
		setResponsePage(getPage());
	}

	/**
	 * Performs the actual action of this component, performing a non-ajax fallback when there was
	 * no AjaxRequestTarget available.
	 * 
	 * @param target
	 *            the request target, when <code>null</code>, a full page refresh will be
	 *            generated
	 */
	public void onClick(AjaxRequestTarget target)
	{
		// Tell the PageableListView which page to print next
		pageable.setCurrentPage(getPageNumber());
	}
}