Tree Node for the for a general tree of Objects
/*
*
* This software is subject to the terms of the Common Public License
* Agreement, available at the following URL:
* http://www.opensource.org/licenses/cpl.html .
* Copyright (C) 2003-2004 TONBELLER AG.
* All Rights Reserved.
* You must accept the terms of that agreement to use this software.
*
*
*
*/
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
* Tree Node for the for a general tree of Objects
*/
public class TreeNode {
private TreeNode parent = null;
private List children = null;
private Object reference;
/**
* cTtor
* @param obj referenced object
*/
public TreeNode(Object obj) {
this.parent = null;
this.reference = obj;
this.children = new ArrayList();
}
/**
* remove node from tree
*/
public void remove() {
if (parent != null) {
parent.removeChild(this);
}
}
/**
* remove child node
* @param child
*/
private void removeChild(TreeNode child) {
if (children.contains(child))
children.remove(child);
}
/**
* add child node
* @param child node to be added
*/
public void addChildNode(TreeNode child) {
child.parent = this;
if (!children.contains(child))
children.add(child);
}
/**
* deep copy (clone)
* @return copy of TreeNode
*/
public TreeNode deepCopy() {
TreeNode newNode = new TreeNode(reference);
for (Iterator iter = children.iterator(); iter.hasNext();) {
TreeNode child = (TreeNode) iter.next();
newNode.addChildNode(child.deepCopy());
}
return newNode;
}
/**
* deep copy (clone) and prune
* @param depth - number of child levels to be copied
* @return copy of TreeNode
*/
public TreeNode deepCopyPrune(int depth) {
if (depth < 0)
throw new IllegalArgumentException("Depth is negative");
TreeNode newNode = new TreeNode(reference);
if (depth == 0)
return newNode;
for (Iterator iter = children.iterator(); iter.hasNext();) {
TreeNode child = (TreeNode) iter.next();
newNode.addChildNode(child.deepCopyPrune(depth - 1));
}
return newNode;
}
/**
* @return level = distance from root
*/
public int getLevel() {
int level = 0;
TreeNode p = parent;
while (p != null) {
++level;
p = p.parent;
}
return level;
}
/**
* walk through subtree of this node
* @param callbackHandler function called on iteration
*/
public int walkTree(TreeNodeCallback callbackHandler) {
int code = 0;
code = callbackHandler.handleTreeNode(this);
if (code != TreeNodeCallback.CONTINUE)
return code;
ChildLoop: for (Iterator iter = children.iterator(); iter.hasNext();) {
TreeNode child = (TreeNode) iter.next();
code = child.walkTree(callbackHandler);
if (code >= TreeNodeCallback.CONTINUE_PARENT)
return code;
}
return code;
}
/**
* walk through children subtrees of this node
* @param callbackHandler function called on iteration
*/
public int walkChildren(TreeNodeCallback callbackHandler) {
int code = 0;
ChildLoop: for (Iterator iter = children.iterator(); iter.hasNext();) {
TreeNode child = (TreeNode) iter.next();
code = callbackHandler.handleTreeNode(child);
if (code >= TreeNodeCallback.CONTINUE_PARENT)
return code;
if (code == TreeNodeCallback.CONTINUE) {
code = child.walkChildren(callbackHandler);
if (code > TreeNodeCallback.CONTINUE_PARENT)
return code;
}
}
return code;
}
/**
* @return List of children
*/
public List getChildren() {
return children;
}
/**
* @return parent node
*/
public TreeNode getParent() {
return parent;
}
/**
* @return reference object
*/
public Object getReference() {
return reference;
}
/**
* set reference object
* @param object reference
*/
public void setReference(Object object) {
reference = object;
}
} // TreeNode
/*
*
* This software is subject to the terms of the Common Public License
* Agreement, available at the following URL:
* http://www.opensource.org/licenses/cpl.html .
* Copyright (C) 2003-2004 TONBELLER AG.
* All Rights Reserved.
* You must accept the terms of that agreement to use this software.
*
*
*
*/
/**
* handle call back for position tree
*/
interface TreeNodeCallback {
public static final int CONTINUE = 0;
public static final int CONTINUE_SIBLING = 1;
public static final int CONTINUE_PARENT = 2;
public static final int BREAK = 3;
/**
* @param node the current node to handle
* @return 0 continue tree walk
* 1 break this node (continue sibling)
* 2 break this level (continue parent level)
* 3 break tree walk
*/
int handleTreeNode(TreeNode node);
} // TreeNodeCallback
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