Please write a Java program, named “LeftMiddleRight.java” and “LeftMiddleRightPa
ID: 3922499 • Letter: P
Question
Please write a Java program, named “LeftMiddleRight.java” and “LeftMiddleRightPanel.java”. This program will generate a window where there are three buttons, named left, middle and right respectively. The window also has a title named “Left Middle Right” and display a message “Click a Button” firstly. Then if the left button is clicked, the window will display “Left”; If the middle button is clicked, the window will display “Middle”; If the right button is clicked, the window will display “Right”;
Explanation / Answer
import java.applet.Applet;
import java.awt.Button;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class LeftMiddleRight extends Applet implements
ActionListener{
String actionMessage="";
public void init(){
//create Buttons
Button Button1 = new Button("Left");
Button Button2 = new Button("Middle");
Button Button3 = new Button("Right");
//add Buttons
add(Button1);
add(Button2);
add(Button3);
//set action listeners for buttons
Button1.addActionListener(this);
Button2.addActionListener(this);
Button3.addActionListener(this);
}
public void paint(Graphics g){
g.drawString("Click a Button",0,50);
g.drawString(actionMessage,10,80);
}
public void actionPerformed(ActionEvent ae){
/*
* Get the action command using
* String getActionCommand() method.
*/
String action = ae.getActionCommand();
if(action.equals("Left"))
actionMessage = "Left Button Pressed";
else if(action.equals("Right"))
actionMessage = "Right Button Pressed";
else if(action.equals("Middle"))
actionMessage = "Middle Button Pressed";
repaint();
}
}
<html>
<title>"Left Middle Right"</title>
<applet code="LeftMiddleRight" width=200 height=200>
</applet>
</html>