ajaxpagingnavigator.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.Component;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.markup.html.link.Link;
import org.apache.wicket.markup.html.navigation.paging.IPageable;
import org.apache.wicket.markup.html.navigation.paging.IPagingLabelProvider;
import org.apache.wicket.markup.html.navigation.paging.PagingNavigation;
import org.apache.wicket.markup.html.navigation.paging.PagingNavigator;
import org.apache.wicket.markup.repeater.AbstractRepeater;

/**
 * A Wicket panel component to draw and maintain a complete page navigator, meant to be easily added
 * to any PageableListView. A navigation which contains links to the first and last page, the
 * current page +- some increment and which supports paged navigation bars (@see
 * PageableListViewNavigationWithMargin).
 * <p>
 * <strong>NOTE</strong> To use the <code>AjaxPagingNavigator</code>, you <i>have</i> to put
 * your <code>ListView</code> in a <code>WebMarkupContainer</code>, otherwise it is not
 * possible to update the contents of the listview using Ajax.
 * 
 * @since 1.2
 * 
 * @author Martijn Dashorst
 */
public class AjaxPagingNavigator extends PagingNavigator
{
	private static final long serialVersionUID = 1L;

	/** The pageable component that needs to be updated. */
	private final IPageable pageable;

	/**
	 * Constructor.
	 * 
	 * @param id
	 *            See Component
	 * @param pageable
	 *            The pageable component the page links are referring to.
	 */
	public AjaxPagingNavigator(final String id, final IPageable pageable)
	{
		this(id, pageable, null);
	}

	/**
	 * Constructor.
	 * 
	 * @param id
	 *            See Component
	 * @param pageable
	 *            The pageable component the page links are referring to.
	 * @param labelProvider
	 *            The label provider for the link text.
	 */
	public AjaxPagingNavigator(final String id, final IPageable pageable,
			final IPagingLabelProvider labelProvider)
	{
		super(id, pageable, labelProvider);
		this.pageable = pageable;
		setOutputMarkupId(true);
	}

	/**
	 * Create a new increment link. May be subclassed to make use of specialized links, e.g. Ajaxian
	 * links.
	 * 
	 * @param id
	 *            the link id
	 * @param pageable
	 *            the pageable to control
	 * @param increment
	 *            the increment
	 * @return the increment link
	 */
	protected Link newPagingNavigationIncrementLink(String id, IPageable pageable, int increment)
	{
		return new AjaxPagingNavigationIncrementLink(id, pageable, increment);
	}

	/**
	 * Create a new pagenumber link. May be subclassed to make use of specialized links, e.g.
	 * Ajaxian links.
	 * 
	 * @param id
	 *            the link id
	 * @param pageable
	 *            the pageable to control
	 * @param pageNumber
	 *            the page to jump to
	 * @return the pagenumber link
	 */
	protected Link newPagingNavigationLink(String id, IPageable pageable, int pageNumber)
	{
		return new AjaxPagingNavigationLink(id, pageable, pageNumber);
	}

	/**
	 * Create a new PagingNavigation. May be subclassed to make us of specialized PagingNavigation.
	 * 
	 * @param pageable
	 *            the pageable component
	 * @param labelProvider
	 *            The label provider for the link text.
	 * @return the navigation object
	 */
	protected PagingNavigation newNavigation(final IPageable pageable,
			final IPagingLabelProvider labelProvider)
	{
		return new AjaxPagingNavigation("navigation", pageable, labelProvider);
	}

	/**
	 * Override this method to specify the markup container where your IPageable is part of. This
	 * implementation is a default implementation that tries to find a parent markup container and
	 * update that container. This is necessary as ListViews can't be updated themselves.
	 * 
	 * @param target
	 *            the request target to add the components that need to be updated in the ajax
	 *            event.
	 */
	protected void onAjaxEvent(AjaxRequestTarget target)
	{
		// update the container (parent) of the pageable, this assumes that
		// the pageable is a component, and that it is a child of a web
		// markup container.

		Component container = ((Component)pageable);
		// no need for a nullcheck as there is bound to be a non-repeater
		// somewhere higher in the hierarchy
		while (container instanceof AbstractRepeater)
		{
			container = container.getParent();
		}
		target.addComponent(container);

		// in case the navigator is not contained by the container, we have
		// to add it to the response
		if (((MarkupContainer)container).contains(this, true) == false)
		{
			target.addComponent(this);
		}
	}
}