Java tutorial
/* * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package components; /* * This code is based on an example provided by Richard Stanford, * a tutorial reader. */ import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.tree.DefaultMutableTreeNode; public class DynamicTreeDemo extends JPanel implements ActionListener { private int newNodeSuffix = 1; private static String ADD_COMMAND = "add"; private static String REMOVE_COMMAND = "remove"; private static String CLEAR_COMMAND = "clear"; private DynamicTree treePanel; public DynamicTreeDemo() { super(new BorderLayout()); //Create the components. treePanel = new DynamicTree(); populateTree(treePanel); JButton addButton = new JButton("Add"); addButton.setActionCommand(ADD_COMMAND); addButton.addActionListener(this); JButton removeButton = new JButton("Remove"); removeButton.setActionCommand(REMOVE_COMMAND); removeButton.addActionListener(this); JButton clearButton = new JButton("Clear"); clearButton.setActionCommand(CLEAR_COMMAND); clearButton.addActionListener(this); //Lay everything out. treePanel.setPreferredSize(new Dimension(300, 150)); add(treePanel, BorderLayout.CENTER); JPanel panel = new JPanel(new GridLayout(0, 3)); panel.add(addButton); panel.add(removeButton); panel.add(clearButton); add(panel, BorderLayout.SOUTH); } public void populateTree(DynamicTree treePanel) { String p1Name = new String("Parent 1"); String p2Name = new String("Parent 2"); String c1Name = new String("Child 1"); String c2Name = new String("Child 2"); DefaultMutableTreeNode p1, p2; p1 = treePanel.addObject(null, p1Name); p2 = treePanel.addObject(null, p2Name); treePanel.addObject(p1, c1Name); treePanel.addObject(p1, c2Name); treePanel.addObject(p2, c1Name); treePanel.addObject(p2, c2Name); } public void actionPerformed(ActionEvent e) { String command = e.getActionCommand(); if (ADD_COMMAND.equals(command)) { //Add button clicked treePanel.addObject("New Node " + newNodeSuffix++); } else if (REMOVE_COMMAND.equals(command)) { //Remove button clicked treePanel.removeCurrentNode(); } else if (CLEAR_COMMAND.equals(command)) { //Clear button clicked. treePanel.clear(); } } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window. JFrame frame = new JFrame("DynamicTreeDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. DynamicTreeDemo newContentPane = new DynamicTreeDemo(); newContentPane.setOpaque(true); //content panes must be opaque frame.setContentPane(newContentPane); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } }