001// Copyright 2011 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.tapestry5.tree;
016
017import org.apache.tapestry5.BaseOptimizedSessionPersistedObject;
018import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
019
020import java.util.Set;
021
022/**
023 * Default implementation of {@link TreeSelectionModel}. This is simply a wrapper around a set of node ids.
024 *
025 * @param <T> type of node
026 */
027public class DefaultTreeSelectionModel<T> extends BaseOptimizedSessionPersistedObject implements TreeSelectionModel<T>
028{
029    private final Set<String> selectedIds = CollectionFactory.newSet();
030
031    public boolean isSelected(TreeNode<T> node)
032    {
033        assert node != null;
034
035        return selectedIds.contains(node.getId());
036    }
037
038    public void select(TreeNode<T> node)
039    {
040        assert node != null;
041
042        if (selectedIds.add(node.getId()))
043            markDirty();
044    }
045
046    public void unselect(TreeNode<T> node)
047    {
048        assert node != null;
049
050        if (selectedIds.remove(node.getId()))
051            markDirty();
052    }
053
054    public void clear()
055    {
056        if (!selectedIds.isEmpty())
057        {
058            selectedIds.clear();
059            markDirty();
060        }
061    }
062}