org.apache.wicket.extensions.markup.html.repeater.tree.Node.java Source code

Introduction

Here is the source code for org.apache.wicket.extensions.markup.html.repeater.tree.Node.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.extensions.markup.html.repeater.tree;

import java.util.Optional;

import org.apache.wicket.Component;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.markup.html.AjaxFallbackLink;
import org.apache.wicket.behavior.Behavior;
import org.apache.wicket.core.util.string.CssUtils;
import org.apache.wicket.extensions.markup.html.repeater.tree.AbstractTree.State;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.html.panel.Panel;
import org.apache.wicket.model.IModel;

/**
 * Representation of a single node in the tree. By default uses an {@link AjaxFallbackLink} for its
 * junction component.
 * 
 * @see #createJunctionComponent(String)
 * 
 * @author svenmeier
 * @param <T>
 *            The model object type
 */
public abstract class Node<T> extends Panel {

    private static final long serialVersionUID = 1L;

    public static final String OTHER_CLASS_KEY = CssUtils.key(Node.class, "other");

    public static final String EXPANDED_CLASS_KEY = CssUtils.key(Node.class, "expanded");

    public static final String COLLAPSED_CLASS_KEY = CssUtils.key(Node.class, "collapsed");

    /**
     * The component id for the content component.
     */
    public static final String CONTENT_ID = "content";

    private AbstractTree<T> tree;

    /**
     * Constructor.
     * 
     * @param id
     *            component id
     * @param tree
     *            the owning tree
     * @param model
     *            the model for this node
     */
    public Node(String id, AbstractTree<T> tree, IModel<T> model) {
        super(id, model);

        this.tree = tree;
    }

    @Override
    protected void onInitialize() {
        super.onInitialize();

        MarkupContainer junction = createJunctionComponent("junction");
        junction.add(new StyleBehavior());
        add(junction);

        Component content = createContent(CONTENT_ID, getModel());
        if (!content.getId().equals(CONTENT_ID)) {
            throw new IllegalArgumentException("content must have component id equal to Node.CONTENT_ID");
        }
        add(content);
    }

    /**
     * @return the model
     */
    @SuppressWarnings("unchecked")
    public IModel<T> getModel() {
        return (IModel<T>) getDefaultModel();
    }

    /**
     * @return the model object
     */
    public T getModelObject() {
        return getModel().getObject();
    }

    /**
     * The junction component expands and collapses this node.
     * 
     * @param id
     *            the component id
     * @return component representing the junction
     */
    protected MarkupContainer createJunctionComponent(String id) {
        return new AjaxFallbackLink<Void>(id) {
            private static final long serialVersionUID = 1L;

            @Override
            public void onClick(Optional<AjaxRequestTarget> targetOptional) {
                toggle();
            }

            @Override
            public boolean isEnabled() {
                return tree.getProvider().hasChildren(Node.this.getModelObject());
            }
        };
    }

    /**
     * Toggle the node.
     * 
     * @see AbstractTree#collapse(Object)
     * @see AbstractTree#expand(Object)
     */
    protected void toggle() {
        T t = getModelObject();

        if (tree.getState(t) == State.EXPANDED) {
            tree.collapse(t);
        } else {
            tree.expand(t);
        }
    }

    /**
     * Create the component to display the actual node's content.
     * 
     * @param id
     *            the component id
     * @param model
     *            the node's model
     * @return the component representing the content
     */
    protected abstract Component createContent(String id, IModel<T> model);

    /**
     * Get the style class depending on the current {@link State} of this node.
     * 
     * @see #getExpandedStyleClass(Object)
     * @see #getCollapsedStyleClass()
     * @see #getOtherStyleClass()
     * @return the style class
     */
    protected String getStyleClass() {
        T t = getModelObject();

        if (tree.getProvider().hasChildren(t)) {
            if (tree.getState(t) == State.EXPANDED) {
                return getExpandedStyleClass(t);
            } else {
                return getCollapsedStyleClass();
            }
        }
        return getOtherStyleClass();
    }

    protected String getExpandedStyleClass(T t) {
        return getString(EXPANDED_CLASS_KEY);
    }

    protected String getCollapsedStyleClass() {
        return getString(COLLAPSED_CLASS_KEY);
    }

    protected String getOtherStyleClass() {
        return getString(OTHER_CLASS_KEY);
    }

    /**
     * Behavior to add the style class attribute.
     * 
     * @see Node#getStyleClass()
     */
    private static class StyleBehavior extends Behavior {
        private static final long serialVersionUID = 1L;

        @Override
        public void onComponentTag(Component component, ComponentTag tag) {
            Node<?> node = (Node<?>) component.getParent();

            String styleClass = node.getStyleClass();
            if (styleClass != null) {
                tag.put("class", styleClass);
            }
        }
    }
}