001// Copyright 2004, 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry.contrib.tree.model;
016
017import java.util.Iterator;
018
019/**
020 * The interface that defines a suitable data model for a <code>TreeView component</code>. 
021 * 
022 * @author ceco
023 */
024public interface ITreeDataModel
025{
026        /**
027         * Returns the root node of the tree
028         */
029        Object getRoot();
030
031        /**
032         * Returns the number of children of parent node.
033         * @param objParent is the parent object whose nr of children are sought
034         */
035        int getChildCount(Object objParent);
036
037        /**
038         * Get an iterator to the Collection of children belonging to the parent node object
039         * @param objParent is the parent object whose children are requested
040         */
041        Iterator getChildren(Object objParent);
042
043        /**
044         * Get the actual node object based on some identifier (for example an UUID)
045         * @param objUniqueKey is the unique identifier of the node object being retrieved
046         * @return the instance of the node object identified by the key
047         */
048        Object getObject(Object objUniqueKey);
049
050        /** 
051         * Get the unique identifier (UUID) of the node object with a certain parent node
052         * @param objTarget is the Object whose identifier is required
053         * @param objParentUniqueKey is the unique id of the parent of objTarget
054         * @return the unique identifier of objTarget
055         */
056        Object getUniqueKey(Object objTarget, Object objParentUniqueKey);
057
058        /**
059         * Get the unique identifier of the parent of an object
060         * @param objChildUniqueKey is the identifier of the Object for which the parent identifier is sought
061         * @return the identifier (possibly UUID) of the parent of objChildUniqueKey
062         */
063        Object getParentUniqueKey(Object objChildUniqueKey);
064
065        /**
066         * Check to see (on the basis of some node object identifier) whether the parent node is indeed the parent of the object
067         * @param objChildUniqueKey is the identifier of the object whose parent is being checked
068         * @param objParentUniqueKey is the identifier of the parent which is to be checked against
069         */
070        boolean isAncestorOf(Object objChildUniqueKey, Object objParentUniqueKey);
071        
072}