| /* |
| * 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.cocoon.forms.formmodel.tree; |
| |
| import java.util.Collection; |
| |
| /** |
| * Data model for the {@link Tree} widget, inspired by Swing's <code>TreeModel</code>, with |
| * the difference that child nodes are accessed through keys rather than indices. |
| * |
| * @version $Id$ |
| */ |
| public interface TreeModel { |
| |
| /** |
| * Returns the root of the tree. Returns <code>null</code> |
| * only if the tree has no nodes. |
| * |
| * @return the root of the tree |
| */ |
| public Object getRoot(); |
| |
| |
| public Collection getChildren(Object parent); |
| |
| /** |
| * Returns <code>true</code> if <code>node</code> is a leaf. |
| * It is possible for this method to return <code>false</code> |
| * even if <code>node</code> has no children. |
| * A directory in a filesystem, for example, |
| * may contain no files; the node representing |
| * the directory is not a leaf, but it also has no children. |
| * |
| * @param node a node in the tree, obtained from this data source |
| * @return true if <code>node</code> is a leaf |
| */ |
| public boolean isLeaf(Object node); |
| |
| public String getChildKey(Object parent, Object child); |
| |
| public Object getChild(Object parent, String key); |
| |
| public Object getNode(TreePath path); |
| |
| /** |
| * Adds a listener for the {@link TreeModelEvent} posted after the tree changes. |
| * |
| * @param l the listener to add |
| */ |
| void addTreeModelListener(TreeModelListener l); |
| |
| /** |
| * Removes a listener previously added with {@link #addTreeModelListener(TreeModelListener)}. |
| * |
| * @param l the listener to remove |
| */ |
| void removeTreeModelListener(TreeModelListener l); |
| |
| } |