org.apache.wicket.markup.html.navigation.paging.PagingNavigationLink.java Source code

Introduction

Here is the source code for org.apache.wicket.markup.html.navigation.paging.PagingNavigationLink.java

Source

/*
 * 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.navigation.paging;

import org.apache.wicket.Page;
import org.apache.wicket.markup.html.link.DisabledAttributeLinkBehavior;
import org.apache.wicket.markup.html.link.Link;

/**
 * A link to a page of a PageableListView.
 * 
 * @author Jonathan Locke
 * @author Eelco Hillenius
 * @author Martijn Dashorst
 * @param <T>
 *            type of model object
 */
public class PagingNavigationLink<T> extends Link<T> {
    private static final long serialVersionUID = 1L;

    /** The pageable list view. */
    protected final IPageable pageable;

    /** The page of the PageableListView this link is for. */
    private final long pageNumber;

    /**
     * Constructor.
     * 
     * @param id
     *            See Component
     * @param pageable
     *            The pageable component for this page link
     * @param pageNumber
     *            The page number in the PageableListView that this link links to. Negative
     *            pageNumbers are relative to the end of the list.
     */
    public PagingNavigationLink(final String id, final IPageable pageable, final long pageNumber) {
        super(id);
        setAutoEnable(true);
        this.pageNumber = pageNumber;
        this.pageable = pageable;

        add(new DisabledAttributeLinkBehavior());
    }

    /**
     * @see org.apache.wicket.markup.html.link.Link#onClick()
     */
    @Override
    public void onClick() {
        pageable.setCurrentPage(getPageNumber());
    }

    /**
     * Get pageNumber.
     * 
     * @return pageNumber.
     */
    public final long getPageNumber() {
        return cullPageNumber(pageNumber);
    }

    /**
     * Allows the link to cull the page number to the valid range before it is retrieved from the
     * link
     * 
     * @param pageNumber
     * @return culled page number
     */
    protected long cullPageNumber(long pageNumber) {
        long idx = pageNumber;
        if (idx < 0) {
            idx = pageable.getPageCount() + idx;
        }

        if (idx > (pageable.getPageCount() - 1)) {
            idx = pageable.getPageCount() - 1;
        }

        if (idx < 0) {
            idx = 0;
        }

        return idx;
    }

    /**
     * @return True if this page is the first page of the containing PageableListView
     */
    public final boolean isFirst() {
        return getPageNumber() == 0;
    }

    /**
     * @return True if this page is the last page of the containing PageableListView
     */
    public final boolean isLast() {
        return getPageNumber() == (pageable.getPageCount() - 1);
    }

    /**
     * Returns true if this PageableListView navigation link links to the given page.
     * 
     * @param page
     *            The page
     * @return True if this link links to the given page
     * @see org.apache.wicket.markup.html.link.Link#linksTo(org.apache.wicket.Page)
     */
    @Override
    public final boolean linksTo(final Page page) {
        return getPageNumber() == pageable.getCurrentPage();
    }
}