    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}