HANDLING EVENTS IN FRAME WINDOW

Since Frame is a subclass of Component, it inherits all the capabilities defined by
Component. This means that you can use and manage a frame window that you create
just like you manage your applet’s main window. For example, you can override
paint( ) to display output, call repaint( ) when you need to restore the window, and
override all event handlers. Whenever an event occurs in a window, the event handlers
defined by that window will be called. Each window handles its own events. For
example, the following program creates a window that responds to mouse events.
The main applet window also responds to mouse events. When you experiment
with this program, you will see that mouse events are sent to the window in which
the event occurs.
// Handle mouse events in both child and applet windows.
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
/*


*/
// Create a subclass of Frame.
class SampleFrame extends Frame
implements MouseListener, MouseMotionListener {
String msg = "";
int mouseX=10, mouseY=40;
int movX=0, movY=0;

SampleFrame(String title) {
super(title);
// register this object to receive its own mouse events
addMouseListener(this);
addMouseMotionListener(this);
// create an object to handle window events
MyWindowAdapter adapter = new MyWindowAdapter(this);
// register it to receive those events
addWindowListener(adapter);
}
// Handle mouse clicked.
public void mouseClicked(MouseEvent me) {
}
// Handle mouse entered.
public void mouseEntered(MouseEvent evtObj) {
// save coordinates
mouseX = 10;
mouseY = 54;
msg = "Mouse just entered child.";
repaint();
}
// Handle mouse exited.
public void mouseExited(MouseEvent evtObj) {
// save coordinates
mouseX = 10;
mouseY = 54;
msg = "Mouse just left child window.";
repaint();
}
// Handle mouse pressed.
public void mousePressed(MouseEvent me) {
// save coordinates
mouseX = me.getX();
mouseY = me.getY();
msg = "Down";
repaint();
}
// Handle mouse released.

public void mouseReleased(MouseEvent me) {
// save coordinates
mouseX = me.getX();
mouseY = me.getY();
msg = "Up";
repaint();
}
// Handle mouse dragged.
public void mouseDragged(MouseEvent me) {
// save coordinates
mouseX = me.getX();
mouseY = me.getY();
movX = me.getX();
movY = me.getY();
msg = "*";
repaint();
}
// Handle mouse moved.
public void mouseMoved(MouseEvent me) {
// save coordinates
movX = me.getX();
movY = me.getY();
repaint(0, 0, 100, 60);
}
public void paint(Graphics g) {
g.drawString(msg, mouseX, mouseY);
g.drawString("Mouse at " + movX + ", " + movY, 10, 40);
}
}
class MyWindowAdapter extends WindowAdapter {
SampleFrame sampleFrame;
public MyWindowAdapter(SampleFrame sampleFrame) {
this.sampleFrame = sampleFrame;
}
public void windowClosing(WindowEvent we) {
sampleFrame.setVisible(false);
}
}

// Applet window.
public class WindowEvents extends Applet
implements MouseListener, MouseMotionListener {
SampleFrame f;
String msg = "";
int mouseX=0, mouseY=10;
int movX=0, movY=0;
// Create a frame window.
public void init() {
f = new SampleFrame("Handle Mouse Events");
f.setSize(300, 200);
f.setVisible(true);
// register this object to receive its own mouse events
addMouseListener(this);
addMouseMotionListener(this);
}
// Remove frame window when stopping applet.
public void stop() {
f.setVisible(false);
}
// Show frame window when starting applet.
public void start() {
f.setVisible(true);
}
// Handle mouse clicked.
public void mouseClicked(MouseEvent me) {
}
// Handle mouse entered.
public void mouseEntered(MouseEvent me) {
// save coordinates
mouseX = 0;
mouseY = 24;
msg = "Mouse just entered applet window.";
repaint();

}
// Handle mouse exited.
public void mouseExited(MouseEvent me) {
// save coordinates
mouseX = 0;
mouseY = 24;
msg = "Mouse just left applet window.";
repaint();
}
// Handle button pressed.
public void mousePressed(MouseEvent me) {
// save coordinates
mouseX = me.getX();
mouseY = me.getY();
msg = "Down";
repaint();
}
// Handle button released.
public void mouseReleased(MouseEvent me) {
// save coordinates
mouseX = me.getX();
mouseY = me.getY();
msg = "Up";
repaint();
}
// Handle mouse dragged.
public void mouseDragged(MouseEvent me) {
// save coordinates
mouseX = me.getX();
mouseY = me.getY();
movX = me.getX();
movY = me.getY();
msg = "*";
repaint();
}
// Handle mouse moved.
public void mouseMoved(MouseEvent me) {

// save coordinates
movX = me.getX();
movY = me.getY();
repaint(0, 0, 100, 20);
}
// Display msg in applet window.
public void paint(Graphics g) {
g.drawString(msg, mouseX, mouseY);
g.drawString("Mouse at " + movX + ", " + movY, 0, 10);
}
}