1 /* 2 * File: ButtonTest.java 3 * 4 * Create some buttons with simple actions 5 * 6 * Copyright: Northeast Parallel Architectures Center 7 * 8 */ 9 10 import java.awt.Button; 11 import java.awt.Color; 12 import java.awt.Font; 13 import java.awt.event.ActionListener; 14 import java.awt.event.ActionEvent; 15 16 public class ButtonTest extends java.applet.Applet 17 implements ActionListener { 18 19 // there are three buttons labelled red, white and blue 20 // this class is the event listener for the buttons 21 22 private Button button1, button2, button3; 23 private Font f = new Font( "Serif", Font.BOLD, 24 ); 24 25 public void init() { 26 setBackground( Color.white ); 27 setFont (f); 28 29 button1 = new Button( "Red" ); 30 button1.addActionListener( this ); 31 add( button1 ); 32 33 button2 = new Button( "White" ); 34 button2.addActionListener( this ); 35 add( button2 ); 36 37 button3 = new Button( "Blue" ); 38 button3.addActionListener( this ); 39 add( button3 ); 40 41 } 42 43 public void actionPerformed( ActionEvent event ) { 44 // to respond to a button click, change the background color of the applet 45 46 String buttonLabel = event.getActionCommand(); 47 48 if ( buttonLabel.equals( "Red" ) ) { 49 setBackground( Color.red ); 50 } else if ( buttonLabel.equals( "White" ) ) { 51 setBackground( Color.white ); 52 } else if ( buttonLabel.equals( "Blue" ) ) { 53 setBackground( Color.blue ); 54 } 55 56 colorButtons(); 57 } 58 59 private void colorButtons() { 60 button1.setBackground( Color.white ); 61 button2.setBackground( Color.white ); 62 button3.setBackground( Color.white ); 63 } 64 65 }