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Trees.javaAPI DocExample4719Mon Apr 06 18:10:26 BST 1998c13.swing

Trees.java

//: Trees.java
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source. 
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com 
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
// media without the express permission of the
// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
// warranty of merchantability, fitness for a
// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher be liable for any
// lost revenue, profit, or data, or for direct,
// indirect, special, consequential, incidental, or
// punitive damages, however caused and regardless of
// the theory of liability, arising out of the use of
// or inability to use software, even if Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
// modified files with clearly commented changes to:
// Bruce@EckelObjects.com. (Please use the same
// address for non-code errors found in the book.)
/////////////////////////////////////////////////

// Simple Swing tree example. Trees can be made
// vastly more complex than this.
package c13.swing;
import java.awt.*;
import java.awt.event.*;
import java.awt.swing.*;
import java.awt.swing.tree.*;

// Takes an array of Strings and makes the first
// element a node and the rest leaves:
class Branch {
  DefaultMutableTreeNode r;
  public Branch(String[] data) {
    r = new DefaultMutableTreeNode(data[0]);
    for(int i = 1; i < data.length; i++)
      r.add(new DefaultMutableTreeNode(data[i]));
  }
  public DefaultMutableTreeNode node() { 
    return r; 
  }
}  

public class Trees extends JPanel {
  String[][] data = {
    { "Colors", "Red", "Blue", "Green" },
    { "Flavors", "Tart", "Sweet", "Bland" },
    { "Length", "Short", "Medium", "Long" },
    { "Volume", "High", "Medium", "Low" },
    { "Temperature", "High", "Medium", "Low" },
    { "Intensity", "High", "Medium", "Low" },
  };
  static int i = 0;
  DefaultMutableTreeNode root, child, chosen;
  JTree tree;
  DefaultTreeModel model;
  public Trees() {
    setLayout(new BorderLayout());
    root = new DefaultMutableTreeNode("root");
    tree = new JTree(root);
    // Add it and make it take care of scrolling:
    add(new JScrollPane(tree), 
      BorderLayout.CENTER);
    // Capture the tree's model:
    model =(DefaultTreeModel)tree.getModel();
    JButton test = new JButton("Press me");
    test.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e){
        if(i < data.length) {
          child = new Branch(data[i++]).node();
          // What's the last one you clicked?
          chosen = (DefaultMutableTreeNode)
            tree.getLastSelectedPathComponent();
          if(chosen == null) chosen = root;
          // The model will create the 
          // appropriate event. In response, the
          // tree will update itself:
          model.insertNodeInto(child, chosen, 0);
          // This puts the new node on the 
          // currently chosen node.
        }
      }
    });
    // Change the button's colors:
    test.setBackground(Color.blue);
    test.setForeground(Color.white);
    JPanel p = new JPanel();
    p.add(test);
    add(p, BorderLayout.SOUTH);
  }
  public static void main(String args[]) {
    Show.inFrame(new Trees(),200,500);
  }
} ///:~