KEY EVENTS

/* Displays a key pressed ny the user. Moves the
* character to the right if the user presses the right arrow
* key and to the left if the user presses the left arrow
* key. Moves ten pixels if the user hold down the
* control key and two pixels otherwise.
*/

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Key extends JFrame
implements KeyListener {
public static int SLOW = 2;
public static int FAST = 10;
private int x=100, y=100;
private char theKey = 'A';
private Font f = new Font("Serif",Font.BOLD,36);
private int deltaX = SLOW;

public Key() {
setFont(f);
addKeyListener(this);
requestFocus();
}
public void paint(Graphics g) {
super.paint(g);
g.drawString(String.valueOf(theKey),x,y);
}
public void keyPressed(KeyEvent event){
int code = event.getKeyCode();
if (code == event.VK_CONTROL) deltaX = FAST;
else
if (code == event.VK_RIGHT){x += deltaX; repaint();}
else if (code == event.VK_LEFT){ x -= deltaX; repaint();}
}
public void keyReleased(KeyEvent event) {
if (event.getKeyCode() == event.VK_CONTROL) deltaX = SLOW;
}
public void keyTyped(KeyEvent event) {
theKey = event.getKeyChar();
repaint();
}
public static void main(String [] args)
{Key f = new Key();
f.setSize(400,400);
f.setVisible(true);
}

}
 

MOUSE EVENTS

/* Fills a red triangle when the user presses the mouse inside it.
* Fills the triangle in blue when the user releases the mouse inside it.
* Draw "Got the mouse" when the user enters an applet, and draws "Lost the mouse"
* when the user exits the applet.
*/

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MouseFrame extends JFrame

{ private int [] x = {50,100,150};
private int [] y = {100,50,100};
private Polygon p = new Polygon(x,y,3);
private int oldx;
private int oldy;
private String mouse="";

MouseFrame() {
addMouseListener(new MousePressListener());
}
public void paint(Graphics g) {
super.paint(g);
g.drawString(mouse,200,200);
g.fillPolygon(p);
}

class MousePressListener extends MouseAdapter {
public void mousePressed(MouseEvent event) {
int x = event.getX();
int y = event.getY();
if (p.contains(x,y)){
setForeground(Color.red);
repaint();
}
}
public void mouseReleased(MouseEvent event) {
int x = event.getX();
int y = event.getY();
if (p.contains(x,y)){
setForeground(Color.blue);
repaint();
}
}
public void mouseEntered(MouseEvent event)
{mouse = "Got the mouse";
repaint();}
public void mouseExited(MouseEvent event)
{mouse = "Lost the mouse";
repaint();}

}
public static void main(String [] args)
{MouseFrame f = new MouseFrame();
f.setSize(440,400);
f.setVisible(true);
}

}

 

/* Drags a triangle to a new location
* using the position of the mouse to
* determine how to move the polygon.
*/

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Mouse extends JFrame
implements MouseMotionListener {
private int [] x = {50,100,150};
private int [] y = {100,50,100};
private Polygon p = new Polygon(x,y,3);
private int oldx;
private int oldy;

public Mouse() {
addMouseListener(new MousePressListener());
addMouseMotionListener(this);
}
public void paint(Graphics g) {
super.paint(g);
g.fillPolygon(p);
}
public void mouseMoved(MouseEvent event) { }
public void mouseDragged(MouseEvent event) {
int x = event.getX();
int y = event.getY();
if (p.contains(x,y)){
p.translate(x-oldx,y-oldy);
oldx=x;
oldy=y;
repaint();
}
}
class MousePressListener extends MouseAdapter {
public void mousePressed(MouseEvent event) {
int x = event.getX();
int y = event.getY();
if (p.contains(x,y)){
oldx = x;
oldy = y;
}
}
}
public static void main(String [] args)
{Mouse f = new Mouse();
f.setSize(440,200);
f.setVisible(true);
}

}