001// Copyright 2011, 2013 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.commons.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 static final long serialVersionUID = -2568582442906389898L;
030
031    private final Set<String> selectedIds = CollectionFactory.newSet();
032
033    public boolean isSelected(TreeNode<T> node)
034    {
035        assert node != null;
036
037        return selectedIds.contains(node.getId());
038    }
039
040    public void select(TreeNode<T> node)
041    {
042        assert node != null;
043
044        if (selectedIds.add(node.getId()))
045            markDirty();
046    }
047
048    public void unselect(TreeNode<T> node)
049    {
050        assert node != null;
051
052        if (selectedIds.remove(node.getId()))
053            markDirty();
054    }
055
056    public void clear()
057    {
058        if (!selectedIds.isEmpty())
059        {
060            selectedIds.clear();
061            markDirty();
062        }
063    }
064}