Java tutorial
/* * 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.panel; import org.apache.wicket.Component; import org.apache.wicket.extensions.breadcrumb.BreadCrumbLink; import org.apache.wicket.extensions.breadcrumb.IBreadCrumbModel; import org.apache.wicket.extensions.breadcrumb.IBreadCrumbParticipant; import org.apache.wicket.markup.html.panel.Panel; import org.apache.wicket.model.IModel; /** * A panel that participates with a {@link IBreadCrumbModel bread crumb model}. The idea is that you * would have a dialog-like component that is much like a wizard, but more decoupled. A typical * setup is that you have a panel, where the content is dynamic but hierarchical in nature, and that * there are links on the panel that <i>take you deeper into the hierarchy<i> * * <p> * An example of using {@link BreadCrumbPanel bread crumb panels} and {@link BreadCrumbLink bread * crumb links}: * * <pre> * add(new BreadCrumbLink("myLink", breadCrumbModel) * { * protected IBreadCrumbParticipant getParticipant(String componentId) * { * return new MyPanel(componentId, breadCrumbModel); * } * }); * </pre> * * where <tt>MyPanel</tt> is a {@link BreadCrumbPanel bread crumb panel} and the link is added to * another {@link BreadCrumbPanel bread crumb panel} instance (this). When clicked, MyPanel will * replace the panel that the link is placed on, and it will set (and add) <tt>MyPanel</tt> as the * active bread crumb in the {@link IBreadCrumbModel bread crumb component model}. * </p> * * @author Eelco Hillenius */ public abstract class BreadCrumbPanel extends Panel implements IBreadCrumbParticipant { private static final long serialVersionUID = 1L; /** The bread crumb model. */ private IBreadCrumbModel breadCrumbModel; /** * Implementation of the participant. */ private final IBreadCrumbParticipant decorated = new BreadCrumbParticipantDelegate(this) { private static final long serialVersionUID = 1L; @Override public IModel<String> getTitle() { return BreadCrumbPanel.this.getTitle(); } }; /** * Construct. * * @param id * Component id * @param breadCrumbModel * The bread crumb model */ public BreadCrumbPanel(final String id, final IBreadCrumbModel breadCrumbModel) { super(id); this.breadCrumbModel = breadCrumbModel; } /** * Construct. * * @param id * Component id * @param breadCrumbModel * The bread crumb model * @param model * The model */ public BreadCrumbPanel(final String id, final IBreadCrumbModel breadCrumbModel, final IModel<?> model) { super(id, model); this.breadCrumbModel = breadCrumbModel; } /** * Activates the {@link BreadCrumbPanel bread crumb panel} that is the result of calling * {@link IBreadCrumbPanelFactory#create(String, IBreadCrumbModel) the create method} of the * bread crumb panel factory. * * @param breadCrumbPanelFactory */ public void activate(final IBreadCrumbPanelFactory breadCrumbPanelFactory) { activate(breadCrumbPanelFactory.create(getId(), breadCrumbModel)); } /** * Activates the provided participant, which typically has the effect of replacing this current * panel with the one provided - as the participant typically would be a {@link BreadCrumbPanel * bread crumb panel} - and updating the bread crumb model of this panel, pushing the bread * crumb for the given participant on top. * * @param participant * The participant to set as the active one */ public void activate(final IBreadCrumbParticipant participant) { // get the currently active participant final IBreadCrumbParticipant active = breadCrumbModel.getActive(); if (active == null) { throw new IllegalStateException("The model has no active bread crumb. Before using " + this + ", you have to have at least one bread crumb in the model"); } // add back button support addStateChange(); // set the bread crumb panel as the active one breadCrumbModel.setActive(participant); } /** * Gets the bread crumb panel. * * @return The bread crumb panel */ public final IBreadCrumbModel getBreadCrumbModel() { return breadCrumbModel; } /** * The participating component == this. * * @see org.apache.wicket.extensions.breadcrumb.IBreadCrumbParticipant#getComponent() */ @Override public Component getComponent() { return decorated.getComponent(); } /** * @see org.apache.wicket.extensions.breadcrumb.IBreadCrumbParticipant#onActivate(org.apache.wicket.extensions.breadcrumb.IBreadCrumbParticipant) */ @Override public void onActivate(final IBreadCrumbParticipant previous) { decorated.onActivate(previous); } /** * Sets the bread crumb panel. * * @param breadCrumbModel * The bread crumb panel */ public final void setBreadCrumbModel(final IBreadCrumbModel breadCrumbModel) { this.breadCrumbModel = breadCrumbModel; } }