Mega Code Archive
Traverse Tree
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/*
Definitive Guide to Swing for Java 2, Second Edition
By John Zukowski
ISBN: 1-893115-78-X
Publisher: APress
*/
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import java.awt.*;
import java.util.*;
public class TraverseTree {
public static void main(String args[]) {
JFrame frame = new JFrame("Traverse Tree");
Object footballNodes[] = { "Giants", "Jets", "Bills" };
Vector footballVector = new NamedVector("Football", footballNodes);
Object newYorkNodes[] = { "Mets", "Yankees", "Rangers", footballVector };
Vector newYorkVector = new NamedVector("New York", newYorkNodes);
Object bostonNodes[] = { "Red Sox", "Celtics", "Bruins" };
Vector bostonVector = new NamedVector("Boston", bostonNodes);
Object denverNodes[] = { "Rockies", "Avalanche", "Broncos" };
Vector denverVector = new NamedVector("Denver", denverNodes);
Object rootNodes[] = { newYorkVector, bostonVector, denverVector };
Vector rootVector = new NamedVector("Root", rootNodes);
JTree tree = new JTree(rootVector);
tree.setRootVisible(true);
TreeModel model = tree.getModel();
Object rootObject = model.getRoot();
if ((rootObject != null)
&& (rootObject instanceof DefaultMutableTreeNode)) {
DefaultMutableTreeNode root = (DefaultMutableTreeNode) rootObject;
// printDescendents(root);
Enumeration breadth = root.breadthFirstEnumeration();
Enumeration depth = root.depthFirstEnumeration();
Enumeration preOrder = root.preorderEnumeration();
printEnumeration(breadth, "Breadth");
// printEnumeration(depth, "Depth");
// printEnumeration(preOrder, "Pre");
}
TreeSelectionListener treeSelectionListener = new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent treeSelectionEvent) {
JTree treeSource = (JTree) treeSelectionEvent.getSource();
TreePath path = treeSource.getSelectionPath();
System.out.println(path);
System.out.println(path.getPath());
System.out.println(path.getParentPath());
System.out.println(((DefaultMutableTreeNode) path
.getLastPathComponent()).getUserObject());
System.out.println(path.getPathCount());
}
};
tree.addTreeSelectionListener(treeSelectionListener);
JScrollPane scrollPane = new JScrollPane(tree);
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
frame.setSize(300, 400);
frame.setVisible(true);
}
private static void printEnumeration(Enumeration e, String label) {
System.out.println("-----" + label + "-----");
while (e.hasMoreElements()) {
System.out.println(e.nextElement());
}
}
public static void printDescendents(TreeNode root) {
System.out.println(root);
Enumeration children = root.children();
if (children != null) {
while (children.hasMoreElements()) {
printDescendents((TreeNode) children.nextElement());
}
}
}
}
class NamedVector extends Vector {
String name;
public NamedVector(String name) {
this.name = name;
}
public NamedVector(String name, Object elements[]) {
this.name = name;
for (int i = 0, n = elements.length; i < n; i++) {
add(elements[i]);
}
}
public String toString() {
return "[" + name + "]";
}
}
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