/*
* Copyright 2006 The Apache Software Foundation.
*
* Licensed 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 com.idega.content.tree;
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 UITreeData tree;
private Stack nodeStack = new Stack();
private Stack idStack = new Stack();
private boolean checkState = true;
private boolean startedWalking = false;
// see interface
public void setTree(UITreeData 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());
System.out.println("TREE STATE BASE");
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;
}
}