Programmers file
1. ButtonHandler
Ans
import java.awt.event.*;
public class ButtonHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.out.println("Action occurred");
System.out.println("Button's command is: "
+ e.getActionCommand());
}
}
2. MouseClickHandler
Ans
import java.awt.*;
import java.awt.event.*;
public class MouseClickHandler extends MouseAdapter {
// We just need the mouseClick handler, so we use
// the Adapter to avoid having to write all the
// event handler methods
public void mouseClicked (MouseEvent e) {
// Do stuff with the mouse click...
}
}
1. ButtonHandler
Ans
import java.awt.event.*;
public class ButtonHandler implements ActionListener {
public void actionPerformed(ActionEvent e) {
System.out.println("Action occurred");
System.out.println("Button's command is: "
+ e.getActionCommand());
}
}
Ans
import java.awt.*;
import java.awt.event.*;
public class MouseClickHandler extends MouseAdapter {
// We just need the mouseClick handler, so we use
// the Adapter to avoid having to write all the
// event handler methods
public void mouseClicked (MouseEvent e) {
// Do stuff with the mouse click...
}
}
3. TestAnonymous
Ans
import java.awt.*;
import java.awt.event.*;
public class TestAnonymous {
private Frame f;
private TextField tf;
public TestAnonymous() {
f = new Frame("Anonymous classes example");
tf = new TextField(30);
}
public void launchFrame() {
Label label = new Label("Click and drag the mouse");
// Add components to the frame
f.add(label, BorderLayout.NORTH);
f.add(tf, BorderLayout.SOUTH);
// Add a listener that uses an anonymous class
f.addMouseMotionListener( new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
String s = "Mouse dragging: X = "+ e.getX()
+ " Y = " + e.getY();
tf.setText(s);
}
}); // <- note the closing parenthesis
f.addMouseListener(new MouseClickHandler());
// Size the frame and make it visible
f.setSize(300, 200);
f.setVisible(true);
}
public static void main(String args[]) {
TestAnonymous obj = new TestAnonymous();
obj.launchFrame();
}
}
4. TestButton
Ans
import java.awt.*;
public class TestButton {
private Frame f;
private Button b;
public TestButton() {
f = new Frame("Test");
b = new Button("Press Me!");
b.setActionCommand("ButtonPressed");
}
public void launchFrame() {
b.addActionListener(new ButtonHandler());
f.add(b,BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
public static void main(String args[]) {
TestButton guiApp = new TestButton();
guiApp.launchFrame();
}
}
5. TestInner
Ans
import java.awt.*;
import java.awt.event.*;
public class TestInner {
private Frame f;
private TextField tf;
public TestInner() {
f = new Frame("Inner classes example");
tf = new TextField(30);
}
public void launchFrame() {
Label label = new Label("Click and drag the mouse");
// Add components to the frame
f.add(label, BorderLayout.NORTH);
f.add(tf, BorderLayout.SOUTH);
// Add a listener that uses an Inner class
f.addMouseMotionListener(this.new MyMouseMotionListener());
f.addMouseListener(new MouseClickHandler());
// Size the frame and make it visible
f.setSize(300, 200);
f.setVisible(true);
}
class MyMouseMotionListener extends MouseMotionAdapter {
public void mouseDragged(MouseEvent e) {
String s = "Mouse dragging: X = "+ e.getX()
+ " Y = " + e.getY();
tf.setText(s);
}
}
public static void main(String args[]) {
TestInner obj = new TestInner();
obj.launchFrame();
}
}
6. TwoListener
Ans
import java.awt.*;
import java.awt.event.*;
public class TwoListener
implements MouseMotionListener,
MouseListener {
private Frame f;
private TextField tf;
public TwoListener() {
f = new Frame("Two listeners example");
tf = new TextField(30);
}
public void launchFrame() {
Label label = new Label("Click and drag the mouse");
// Add components to the frame
f.add(label, BorderLayout.NORTH);
f.add(tf, BorderLayout.SOUTH);
// Add this object as a listener
f.addMouseMotionListener(this);
f.addMouseListener(this);
// Size the frame and make it visible
f.setSize(300, 200);
f.setVisible(true);
}
// These are MouseMotionListener events
public void mouseDragged(MouseEvent e) {
String s = "Mouse dragging: X = " + e.getX()
+ " Y = " + e.getY();
tf.setText(s);
}
public void mouseEntered(MouseEvent e) {
String s = "The mouse entered";
tf.setText(s);
}
public void mouseExited(MouseEvent e) {
String s = "The mouse has left the building";
tf.setText(s);
}
// Unused MouseMotionListener method.
// All methods of a listener must be present in the
// class even if they are not used.
public void mouseMoved(MouseEvent e) { }
// Unused MouseListener methods.
public void mousePressed(MouseEvent e) { }
public void mouseClicked(MouseEvent e) { }
public void mouseReleased(MouseEvent e) { }
public static void main(String args[]) {
TwoListener two = new TwoListener();
two.launchFrame();
}
}
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