eu.esdihumboldt.hale.server.webapp.components.SimpleBreadcrumbPanel.java Source code

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Here is the source code for eu.esdihumboldt.hale.server.webapp.components.SimpleBreadcrumbPanel.java

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/*
 * Copyright (c) 2012 Data Harmonisation Panel
 * 
 * All rights reserved. This program and the accompanying materials are made
 * available under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Contributors:
 *     HUMBOLDT EU Integrated Project #030962
 *     Data Harmonisation Panel <http://www.dhpanel.eu>
 */

package eu.esdihumboldt.hale.server.webapp.components;

import java.util.Vector;

import org.apache.wicket.Page;
import org.apache.wicket.markup.html.WebMarkupContainer;
import org.apache.wicket.markup.html.WebPage;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.link.BookmarkablePageLink;
import org.apache.wicket.markup.html.link.ExternalLink;
import org.apache.wicket.markup.html.list.ListItem;
import org.apache.wicket.markup.html.list.ListView;
import org.apache.wicket.markup.html.panel.Panel;

import eu.esdihumboldt.hale.server.webapp.util.PageDescription;

/**
 * A panel which displays simple breadcrumbs
 * 
 * @author Michel Kraemer
 */
public class SimpleBreadcrumbPanel extends Panel {

    /**
     * The serial version UID
     */
    private static final long serialVersionUID = 27264261659073154L;

    /**
     * Constructs a new breadcrumb panel. If a link to a root website should be
     * part of the breadcrumbs, then <code>rootLinkName</code> and
     * <code>rootLinkTarget</code> must both be set.
     * 
     * @param id the component's id
     * @param currentPage the class of the current page
     * @param rootLinkName the title of the link to the root website (can be
     *            null)
     * @param rootLinkTarget the href target of the link to the root website
     *            (can be null)
     */
    public SimpleBreadcrumbPanel(String id, Class<? extends Page> currentPage, final String rootLinkName,
            final String rootLinkTarget) {
        super(id);

        String title = "";
        PageDescription anno = currentPage.getAnnotation(PageDescription.class);
        if (anno != null) {
            if (anno.title() == null) {
                throw new RuntimeException(currentPage + " has no annotated title");
            }
            title = anno.title();
        }

        add(new Label("breadcrumb-current", title));

        // add bread crumbs
        Vector<Class<? extends Page>> links = new Vector<Class<? extends Page>>();
        while (anno != null && anno.parent() != null) {
            Class<? extends WebPage> par = anno.parent();
            if (!par.isAnnotationPresent(PageDescription.class)) {
                break;
            }
            links.insertElementAt(anno.parent(), 0);
            anno = anno.parent().getAnnotation(PageDescription.class);
        }

        // add a dummy element for the root web page (but don't do this if the
        // current page *is* the root page)
        if (rootLinkName != null && rootLinkTarget != null) {
            boolean root = false;
            if (currentPage.isAnnotationPresent(PageDescription.class)) {
                root = currentPage.getAnnotation(PageDescription.class).root();
            }
            if (!root) {
                links.insertElementAt(null, 0);
            }
        }

        // fill list view with bread crumbs
        add(new ListView<Class<? extends Page>>("breadcrumb-panel", links) {

            private static final long serialVersionUID = 1221964671030364825L;

            @Override
            public void populateItem(final ListItem<Class<? extends Page>> item) {
                Class<? extends Page> p = item.getModelObject();
                WebMarkupContainer link;
                if (p != null) {
                    link = new BookmarkablePageLink<Void>("breadcrumb-link", p);
                    PageDescription anno = p.getAnnotation(PageDescription.class);
                    link.add(new Label("breadcrumb-link-text", anno.title()));
                } else {
                    link = new ExternalLink("breadcrumb-link", rootLinkTarget);
                    link.add(new Label("breadcrumb-link-text", rootLinkName));
                }
                item.add(link);
            }
        });
    }
}