/* * Copyright (c) 2000 David Flanagan.  All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */package com.davidflanagan.examples.gui;import java.awt.*;          // For Graphics object and colorsimport javax.swing.*;       // For JPanel componentimport java.awt.event.*;    // For ActionListener interfaceimport javax.swing.event.*; // For ListSelectionListener interface/** * This scribble component includes a JButton to clear the screen, and * a JList that lets the user select a drawing color.  It uses * event listener objects to handle events from those sub-components. **/public class ScribblePane3 extends ScribblePane2 {    // These are colors the user can choose from    Color[] colors = new Color[] { Color.black, Color.red, Color.blue };    // These are names for those colors    String[] colorNames = new String[] { "Black", "Red", "Blue" };    // Add JButton and JList components to the panel.    public ScribblePane3() {	// Implicit super() call here invokes the superclass constructor	// Add a "Clear" button to the panel.	// Handle button events with an action listener	JButton clear = new JButton("Clear");	clear.addActionListener(new ActionListener() {		public void actionPerformed(ActionEvent e) { clear(); }	    });	this.add(clear);	// Add a JList to allow color choices.	// Handle list selection events with a ListSelectionListener.	final JList colorList = new JList(colorNames);	colorList.addListSelectionListener(new ListSelectionListener() {		public void valueChanged(ListSelectionEvent e) {		    setColor(colors[colorList.getSelectedIndex()]);		}	    });	this.add(colorList);    }}