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package echopointng.tree;
/*
* This file is part of the Echo Point Project. This project is a collection
* of Components that have extended the Echo Web Application Framework.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
/*
* The design paradigm and class name used within have been taken directly from
* the java.swing package has been retro-fitted to work with the NextApp Echo web framework.
*
* This file was made part of the EchoPoint project on the 25/07/2002.
*
*/
import java.io.Serializable;
/**
* Represents a path to a node. A TreePath is an array of Objects that are
* vended from a TreeModel. The elements of the array are ordered such
* that the root is always the first element (index 0) of the array.
* TreePath is Serializable, but if any components of
* the path are not serializable, it will not be written out.
*/
public class TreePath implements Serializable {
/** Path representing the parent, null if lastPathComponent represents
* the root. */
private TreePath parentPath;
/** Last path component. */
transient private Object lastPathComponent;
/**
* Primarily provided for subclasses that don't wish to use the path ivar.
* If a subclass uses this, it should also subclass getPath(),
* getPathCount(), getPathComponent() and possibly equals.
*/
protected TreePath() {
}
/**
* Constructs a path from an array of Objects, uniquely identifying
* the path from the root of the tree to a specific node, as returned
* by the tree's data model.
*
* The model is free to return an array of any Objects it needs to
* represent the path. The DefaultTreeModel returns an array of
* TreeNode objects. The first TreeNode in the path is the root of the
* tree, the last TreeNode is the node identified by the path.
*
* @param path an array of Objects representing the path to a node
*/
public TreePath(Object[] path) {
if (path == null || path.length == 0)
throw new IllegalArgumentException("path in TreePath must be non null and not empty.");
lastPathComponent = path[path.length - 1];
if (path.length > 1)
parentPath = new TreePath(path, path.length - 1);
}
protected TreePath(Object[] path, int length) {
lastPathComponent = path[length - 1];
if (length > 1)
parentPath = new TreePath(path, length - 1);
}
/**
* Constructs a TreePath this is the combination of all the path elements
* in parent with a last path component of
* lastElement.
*/
public TreePath(TreePath parent, Object lastElement) {
if (lastElement == null)
throw new IllegalArgumentException("path in TreePath must be non null.");
parentPath = parent;
lastPathComponent = lastElement;
}
/**
* Constructs a TreePath when there is only item in the path.
*
*/
public TreePath(Object singlePath) {
if (singlePath == null)
throw new IllegalArgumentException("path in TreePath must be non null.");
lastPathComponent = singlePath;
parentPath = null;
}
/**
* Tests two TreePaths for equality by checking each element of the
* paths for equality.
*
* @param o the Object to compare
*/
public boolean equals(Object o) {
if (o == this)
return true;
if (o instanceof TreePath) {
TreePath oTreePath = (TreePath) o;
if (getPathCount() != oTreePath.getPathCount())
return false;
for (TreePath path = this; path != null; path = path.parentPath) {
if (path.lastPathComponent == null && oTreePath.lastPathComponent != null) {
return false;
} else if (path.lastPathComponent != null && !(path.lastPathComponent.equals(oTreePath.lastPathComponent))) {
return false;
}
oTreePath = oTreePath.parentPath;
}
return true;
}
return false;
}
/**
* Returns the last component of this path. For a path
* returned by the DefaultTreeModel, that is the TreeNode object
* for the node specified by the path.
*
* @return the Object at the end of the path
*/
public Object getLastPathComponent() {
return lastPathComponent;
}
/**
* Returns a path containing all the elements of the receiver, accept
* the last path component.
*/
public TreePath getParentPath() {
return parentPath;
}
/**
* Returns an array of Objects containing the components of this
* TreePath.
*
* @return an array of Objects representing the TreePath
*/
public Object[] getPath() {
int i = getPathCount();
Object[] result = new Object[i--];
for (TreePath path = this; path != null; path = path.parentPath) {
result[i--] = path.lastPathComponent;
}
return result;
}
/**
* Returns the path component at the specified index.
*
* @param element an int specifying an element in the path, where
* 0 is the first element in the path
* @return the Object at that index location
* @throws IllegalArgumentException if the index is beyond the length
* of the path
*/
public Object getPathComponent(int element) {
int pathLength = getPathCount();
if (element < 0 || element >= pathLength)
throw new IllegalArgumentException("Index " + element + " is out of the specified range");
TreePath path = this;
for (int i = pathLength - 1; i != element; i--) {
path = path.parentPath;
}
return path.lastPathComponent;
}
/**
* Returns the number of elements in the path.
*
* @return an int giving a count of items the path
*/
public int getPathCount() {
int result = 0;
for (TreePath path = this; path != null; path = path.parentPath) {
result++;
}
return result;
}
/**
* Returns the hashCode for the object. The hash code of a TreePath
* is defined to be the hash code of the last component in the path.
*
* @return the hashCode for the object
*/
public int hashCode() {
return lastPathComponent.hashCode();
}
/**
* Returns true if the specified node is a descendant of this
* TreePath. A TreePath, child, is a descendent of another TreePath,
* parent, if child contains all of the components that make up
* parent's path.
*
* @return true if aTreePath is a descendant of the receiver.
*/
public boolean isDescendant(TreePath aTreePath) {
if (aTreePath == this)
return true;
if (aTreePath != null) {
int pathLength = getPathCount();
int oPathLength = aTreePath.getPathCount();
if (oPathLength < pathLength)
// Can't be a descendant, has fewer components in the path.
return false;
while (oPathLength-- > pathLength)
aTreePath = aTreePath.getParentPath();
return equals(aTreePath);
}
return false;
}
/**
* Returns a new path containing all the elements of this receiver
* plus child. This will throw a NullPointerException
* if child is null.
*/
public TreePath pathByAddingChild(Object child) {
if (child == null)
throw new NullPointerException("Null child not allowed");
return new TreePath(this, child);
}
/**
* Returns a string that displays and identifies this
* object's properties.
*
* @return a String representation of this object
*/
public String toString() {
StringBuffer tempSpot = new StringBuffer("[");
for (int counter = 0, maxCounter = getPathCount(); counter < maxCounter; counter++) {
if (counter > 0)
tempSpot.append(", ");
tempSpot.append(getPathComponent(counter));
}
tempSpot.append("]");
return tempSpot.toString();
}
}