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JSF components and utilities that can be used with any JSF implementation. This library is based on the JSF1.1 version of Tomahawk, but with minor source code and build changes to take advantage of JSF1.2 features. A JSF1.2 implementation is required to use this version of the Tomahawk library.
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/*
 * 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.myfaces.custom.tree2;

import org.apache.commons.lang.StringUtils;
import java.util.Stack;

/**
 * A base implementation of the {@link TreeWalker} interface.  Uses a simple node naming
 * scheme of "0" for the root node, "0:0" for the first child, "0:1" for the second child, etc.
 */
public class TreeWalkerBase implements TreeWalker
{
    private String ROOT_NODE_ID = "0";
    private String TREE_NODE_SEPARATOR = ":";

    private Tree tree;
    private Stack nodeStack = new Stack();
    private Stack idStack = new Stack();
    private boolean checkState = true;
    private boolean startedWalking = false;

    // see interface
    public void setTree(Tree tree)
    {
        this.tree = tree;
    }

    // see interface
    public boolean isCheckState()
    {
        return checkState;
    }

    // see interface
    public void setCheckState(boolean checkState)
    {
        this.checkState = checkState;
    }

    // see interface
    public boolean next()
    {
        if (!startedWalking)
        {
            // the first next() call just needs to set the root node and push it onto the stack
            idStack.push(ROOT_NODE_ID);
            tree.setNodeId(ROOT_NODE_ID);
            nodeStack.push(tree.getNode());

            startedWalking = true;
            return true;
        }

        if (nodeStack.isEmpty())
        {
            return false;
        }

        TreeNode prevNode = (TreeNode)nodeStack.peek();
        String prevNodeId = (String)idStack.peek();

        if (prevNode.isLeaf())
        {
            nodeStack.pop();
            idStack.pop();

            return next();
        }
        else
        {
            TreeNode nextNode = null;
            String nextNodeId = null;

            if (prevNodeId.equals(tree.getNodeId()))
            {
                /**
                 * We know there is at least one child b/c otherwise we would have popped the node after
                 * checking isLeaf.  Basically we need to keep drilling down until we reach the deepest
                 * node that is available for "walking."  Then we'll return to the parent and render its
                 * siblings and walk back up the tree.
                 */
                nextNodeId = prevNodeId + TREE_NODE_SEPARATOR + "0";

                // don't render any children if the node is not expanded
                if (checkState)
                {
                    if (!tree.getDataModel().getTreeState().isNodeExpanded(prevNodeId))
                    {
                        nodeStack.pop();
                        idStack.pop();

                        return next();
                    }
                }
            }
            else
            {
                // get the parent node
                String currentNodeId = tree.getNodeId();
                String parentNodeId = StringUtils.substringBeforeLast(currentNodeId, TREE_NODE_SEPARATOR);
                tree.setNodeId(parentNodeId);
                TreeNode parentNode = tree.getNode();

                int siblingCount = Integer.parseInt(currentNodeId.substring(parentNodeId.length()+1));
                siblingCount++;

                if (siblingCount == parentNode.getChildCount())
                {
                    // no more siblings
                    nodeStack.pop();
                    idStack.pop();

                    return next();
                }

                nextNodeId = parentNodeId + TREE_NODE_SEPARATOR + siblingCount;
            }

            tree.setNodeId(nextNodeId);
            nextNode = tree.getNode();

            nodeStack.push(nextNode);
            idStack.push(nextNodeId);

            return true;
        }
    }

    // see interface
    public String getRootNodeId()
    {
        return ROOT_NODE_ID;
    }

    // see interface
    public void reset()
    {
        nodeStack.empty();
        idStack.empty();
        startedWalking = false;
    }
}