Author: Nobuo Tamemasa

Add a checkbox to each node. A single click can select the entire branch or just one item.

Sample demo code:

/* (swing1.1) */
//package jp.gr.java_conf.tame.swing.examples;

import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import javax.swing.border.*;

import jp.gr.java_conf.tame.swing.tree.*;

/**
 * @version 1.1 01/15/99
 */
public class CheckNodeTreeExample extends JFrame {


  
  public CheckNodeTreeExample() {
    super("CheckNode TreeExample");
    String[] strs = {"swing",     // 0
                     "platf",     // 1
                     "basic",     // 2
                     "metal",     // 3
                     "JTree"};    // 4
                                             
    CheckNode[] nodes = new CheckNode[strs.length];
    for (int i=0;i<strs.length;i++) {
      nodes[i] = new CheckNode(strs[i]); 
    }
    nodes[0].add(nodes[1]);
    nodes[1].add(nodes[2]);
    nodes[1].add(nodes[3]);
    nodes[0].add(nodes[4]);
    nodes[3].setSelected(true);
    JTree tree = new JTree( nodes[0] );
    tree.setCellRenderer(new CheckRenderer());
    tree.getSelectionModel().setSelectionMode(
      TreeSelectionModel.SINGLE_TREE_SELECTION
    );
    tree.putClientProperty("JTree.lineStyle", "Angled");
    tree.addMouseListener(new NodeSelectionListener(tree));
    JScrollPane sp = new JScrollPane(tree);
    
    ModePanel mp = new ModePanel(nodes);
    JTextArea textArea = new JTextArea(3,10);
    JScrollPane textPanel = new JScrollPane(textArea);
    JButton button = new JButton("print");
    button.addActionListener(
      new ButtonActionListener(nodes[0], textArea));
    JPanel panel = new JPanel(new BorderLayout());
    panel.add(mp,     BorderLayout.CENTER);
    panel.add(button, BorderLayout.SOUTH);
    
    getContentPane().add(sp,    BorderLayout.CENTER);
    getContentPane().add(panel, BorderLayout.EAST);
    getContentPane().add(textPanel, BorderLayout.SOUTH);
  }

  class NodeSelectionListener extends MouseAdapter {
    JTree tree;
    
    NodeSelectionListener(JTree tree) {
      this.tree = tree;
    }
    
    public void mouseClicked(MouseEvent e) {
      int x = e.getX();
      int y = e.getY();
      int row = tree.getRowForLocation(x, y);
      TreePath  path = tree.getPathForRow(row);
      //TreePath  path = tree.getSelectionPath();
      if (path != null) {
        CheckNode node = (CheckNode)path.getLastPathComponent();
        boolean isSelected = ! (node.isSelected());
        node.setSelected(isSelected);
        if (node.getSelectionMode() == CheckNode.DIG_IN_SELECTION) {
          if ( isSelected ) {
            tree.expandPath(path);
          } else {
            tree.collapsePath(path);
          }
        }
        ((DefaultTreeModel)tree.getModel()).nodeChanged(node);
        // I need revalidate if node is root.  but why?
        if (row == 0) {
          tree.revalidate();
          tree.repaint();
        }
      }
    }
  }
  
  class ModePanel extends JPanel implements ActionListener {
    CheckNode[] nodes;
    JRadioButton b_single,  b_dig_in;
    
    ModePanel(CheckNode[] nodes) {
      this.nodes = nodes;
      setLayout(new GridLayout(2,1));
      setBorder(new TitledBorder("Check Mode"));
      ButtonGroup group = new ButtonGroup();
      add(b_dig_in = new JRadioButton("DIG_IN  "));
      add(b_single = new JRadioButton("SINGLE  "));
      group.add(b_dig_in);
      group.add(b_single);
      b_dig_in.addActionListener(this);
      b_single.addActionListener(this);
      b_dig_in.setSelected(true);
    }
    
    public void actionPerformed(ActionEvent e) {
      int mode;
      if (b_single == e.getSource()) {
        mode = CheckNode.SINGLE_SELECTION;
      } else {
        mode = CheckNode.DIG_IN_SELECTION;
      }
      for (int i=0;i<nodes.length;i++) {
        nodes[i].setSelectionMode(mode);
      }
    }
  }
  
  class ButtonActionListener implements ActionListener {
    CheckNode root;
    JTextArea textArea;
    
    ButtonActionListener(final CheckNode root,
                         final JTextArea textArea) {
      this.root     = root;
      this.textArea = textArea;
    }
    
    public void actionPerformed(ActionEvent e) {
      Enumeration enum = root.breadthFirstEnumeration();
      while (enum.hasMoreElements()) {
        CheckNode node = (CheckNode)enum.nextElement();
        if (node.isSelected()) {
          TreeNode[] nodes = node.getPath();
          textArea.append("\n" + nodes[0].toString());
          for (int i=1;i<nodes.length;i++) {
            textArea.append("/" + nodes[i].toString());
          }
        }
      }
    }
  }

  public static void main(String args[]) {
    CheckNodeTreeExample frame = new CheckNodeTreeExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {System.exit(0);}
    });
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

Download Source Files

Posted On: 17-Jan-1999

internet.commerce