/*
* 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.breadcrumb;
import java.util.ArrayList;
import java.util.List;
import org.apache.wicket.Component;
import org.apache.wicket.markup.html.basic.Label;
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 org.apache.wicket.model.IDetachable;
import org.apache.wicket.model.LoadableDetachableModel;
/**
* A component that renders bread crumbs. By default, it renders a horizontal list from left to
* right (oldest left) with bread crumb links and a ' / ' as a separator, e.g.
*
* <pre>
* first / second / third
* </pre>
*
* <p>
* Delegates how the bread crumb model works to {@link DefaultBreadCrumbsModel}.
* </p>
* <p>
* Override and provide your own markup file if you want to work with other elements, e.g. uls
* instead of spans.
* </p>
*
* @author Eelco Hillenius
*/
public class BreadCrumbBar extends Panel implements IBreadCrumbModel
{
/** Default crumb component. */
private static final class BreadCrumbComponent extends Panel
{
private static final long serialVersionUID = 1L;
/**
* Construct.
*
* @param id
* Component id
* @param separatorMarkup
* markup used as a separator between breadcrumbs
* @param index
* The index of the bread crumb
* @param breadCrumbModel
* The bread crumb model
* @param breadCrumbParticipant
* The bread crumb
* @param enableLink
* Whether the link should be enabled
*/
public BreadCrumbComponent(final String id, final String separatorMarkup, final long index,
final IBreadCrumbModel breadCrumbModel,
final IBreadCrumbParticipant breadCrumbParticipant, final boolean enableLink)
{
super(id);
add(new Label("sep", (index > 0) ? separatorMarkup : "").setEscapeModelStrings(false)
.setRenderBodyOnly(true));
BreadCrumbLink link = new BreadCrumbLink("link", breadCrumbModel)
{
private static final long serialVersionUID = 1L;
@Override
protected IBreadCrumbParticipant getParticipant(final String componentId)
{
return breadCrumbParticipant;
}
};
link.setEnabled(enableLink);
add(link);
link.add(new Label("label", breadCrumbParticipant.getTitle()).setRenderBodyOnly(true));
}
}
/**
* List view for rendering the bread crumbs.
*/
protected class BreadCrumbsListView extends ListView<IBreadCrumbParticipant>
implements
IBreadCrumbModelListener
{
private static final long serialVersionUID = 1L;
private transient boolean dirty = false;
private transient int size = 0;
/**
* Construct.
*
* @param id
* Component id
*/
public BreadCrumbsListView(final String id)
{
super(id);
setReuseItems(false);
setDefaultModel(new LoadableDetachableModel<List<IBreadCrumbParticipant>>()
{
private static final long serialVersionUID = 1L;
@Override
protected List<IBreadCrumbParticipant> load()
{
// save a copy
List<IBreadCrumbParticipant> l = new ArrayList<IBreadCrumbParticipant>(
allBreadCrumbParticipants());
size = l.size();
return l;
}
});
}
@Override
public void breadCrumbActivated(final IBreadCrumbParticipant previousParticipant,
final IBreadCrumbParticipant breadCrumbParticipant)
{
signalModelChange();
}
@Override
public void breadCrumbAdded(final IBreadCrumbParticipant breadCrumbParticipant)
{
}
@Override
public void breadCrumbRemoved(final IBreadCrumbParticipant breadCrumbParticipant)
{
}
/**
* Signal model change.
*/
private void signalModelChange()
{
// else let the listview recalculate it's children immediately;
// it was attached, but it needs to go through that again now
// as the signaling component attached after this
getDefaultModel().detach();
}
/**
* @see org.apache.wicket.markup.html.list.ListView#onBeforeRender()
*/
@Override
protected void onBeforeRender()
{
super.onBeforeRender();
if (dirty)
{
dirty = false;
}
}
@Override
protected void populateItem(final ListItem<IBreadCrumbParticipant> item)
{
long index = item.getIndex();
IBreadCrumbParticipant breadCrumbParticipant = (IBreadCrumbParticipant)item.getDefaultModelObject();
item.add(newBreadCrumbComponent("crumb", index, size, breadCrumbParticipant));
}
}
private static final long serialVersionUID = 1L;
private final IBreadCrumbModel decorated;
/**
* Construct.
*
* @param id
* Component id
*/
public BreadCrumbBar(final String id)
{
super(id);
decorated = new DefaultBreadCrumbsModel();
BreadCrumbsListView breadCrumbsListView = new BreadCrumbsListView("crumbs");
addListener(breadCrumbsListView);
add(breadCrumbsListView);
}
@Override
public void addListener(final IBreadCrumbModelListener listener)
{
decorated.addListener(listener);
}
@Override
public List<IBreadCrumbParticipant> allBreadCrumbParticipants()
{
return decorated.allBreadCrumbParticipants();
}
@Override
public IBreadCrumbParticipant getActive()
{
return decorated.getActive();
}
@Override
public void removeListener(final IBreadCrumbModelListener listener)
{
decorated.removeListener(listener);
}
@Override
public void setActive(final IBreadCrumbParticipant breadCrumbParticipant)
{
decorated.setActive(breadCrumbParticipant);
}
/**
* Gets whether the current bread crumb should be displayed as a link (e.g. for refreshing) or
* as a disabled link (effectively just a label). The latter is the default. Override if you
* want different behavior.
*
* @return Whether the current bread crumb should be displayed as a link; this method returns
* false
*/
protected boolean getEnableLinkToCurrent()
{
return false;
}
/**
* @return markup used as a separator between breadcrumbs. By default <code>/</code> is used,
* but <code>>></code> is also a popular choice.
*/
protected String getSeparatorMarkup()
{
return "/";
}
/**
* Creates a new bread crumb component. That component will be rendered as part of the bread
* crumbs list (which is a <ul> <li> structure).
*
* @param id
* The component id
* @param index
* The index of the bread crumb
* @param total
* The total number of bread crumbs in the current model
* @param breadCrumbParticipant
* the bread crumb
* @return A new bread crumb component
*/
protected Component newBreadCrumbComponent(final String id, final long index, final int total,
final IBreadCrumbParticipant breadCrumbParticipant)
{
boolean enableLink = getEnableLinkToCurrent() || (index < (total - 1));
return new BreadCrumbComponent(id, getSeparatorMarkup(), index, this,
breadCrumbParticipant, enableLink);
}
@Override
protected void onDetach()
{
super.onDetach();
for (IBreadCrumbParticipant crumb : decorated.allBreadCrumbParticipants())
{
if (crumb instanceof Component)
{
((Component)crumb).detach();
}
else if (crumb instanceof IDetachable)
{
((IDetachable)crumb).detach();
}
}
}
}