import java.awt.*;

import java.awt.event.*;

import java.net.*;

import java.util.Map;

import java.util.HashMap;

import javax.swing.*;

public class KeyboardAnimation implements ActionListener

{

private final static String PRESSED = "pressed ";

private final static String RELEASED = "released ";

private JComponent component;

private Timer timer;

private Map<String, Point> pressedKeys = new HashMap<String, Point>();

public KeyboardAnimation(JComponent component, int delay)

{

this.component = component;

timer = new Timer(delay, this);

timer.setInitialDelay( 0 );

}

/*

* &param keyStroke - see KeyStroke.getKeyStroke(String) for the format of

* of the String. Except the "pressed|released" keywords

* are not to be included in the string.

*/

public void addAction(String keyStroke, int deltaX, int deltaY)

{

// Separate the key identifier from the modifiers of the KeyStroke

int offset = keyStroke.lastIndexOf(" ");

String key = offset == -1 ? keyStroke : keyStroke.substring( offset + 1 );

String modifiers = keyStroke.replace(key, "");

// Get the InputMap and ActionMap of the component

InputMap inputMap = component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);

ActionMap actionMap = component.getActionMap();

// Create Action and add binding for the pressed key

Action pressedAction = new AnimationAction(key, new Point(deltaX, deltaY));

String pressedKey = modifiers + PRESSED + key;

KeyStroke pressedKeyStroke = KeyStroke.getKeyStroke(pressedKey);

inputMap.put(pressedKeyStroke, pressedKey);

actionMap.put(pressedKey, pressedAction);

// Create Action and add binding for the released key

Action releasedAction = new AnimationAction(key, null);

String releasedKey = modifiers + RELEASED + key;

KeyStroke releasedKeyStroke = KeyStroke.getKeyStroke(releasedKey);

inputMap.put(releasedKeyStroke, releasedKey);

actionMap.put(releasedKey, releasedAction);

}

// Invoked whenever a key is pressed or released

private void handleKeyEvent(String key, Point moveDelta)

{

// Keep track of which keys are pressed

if (moveDelta == null)

pressedKeys.remove( key );

else

pressedKeys.put(key, moveDelta);

// Start the Timer when the first key is pressed

if (pressedKeys.size() == 1)

{

timer.start();

}

// Stop the Timer when all keys have been released

if (pressedKeys.size() == 0)

{

timer.stop();

}

}

// Invoked when the Timer fires

public void actionPerformed(ActionEvent e)

{

moveComponent();

}

// Move the component to its new location

private void moveComponent()

{

int componentWidth = component.getSize().width;

int componentHeight = component.getSize().height;

Dimension parentSize = component.getParent().getSize();

int parentWidth = parentSize.width;

int parentHeight = parentSize.height;

// Calculate new move

int deltaX = 0;

int deltaY = 0;

for (Point delta : pressedKeys.values())

{

deltaX += delta.x;

deltaY += delta.y;

}

// Determine next X position

int nextX = Math.max(component.getLocation().x + deltaX, 0);

if ( nextX + componentWidth > parentWidth)

{

nextX = parentWidth - componentWidth;

}

// Determine next Y position

int nextY = Math.max(component.getLocation().y + deltaY, 0);

if ( nextY + componentHeight > parentHeight)

{

nextY = parentHeight - componentHeight;

}

// Move the component

component.setLocation(nextX, nextY);

}

// Action to keep track of the key and a Point to represent the movement

// of the component. A null Point is specified when the key is released.

private class AnimationAction extends AbstractAction implements ActionListener

{

private Point moveDelta;

public AnimationAction(String key, Point moveDelta)

{

super(key);

this.moveDelta = moveDelta;

}

public void actionPerformed(ActionEvent e)

{

handleKeyEvent((String)getValue(NAME), moveDelta);

}

}

public static void main(String[] args)

{

JPanel contentPane = new JPanel();

contentPane.setLayout( null );

JLabel label = new JLabel( new ColorIcon(Color.BLUE, 40, 40) );

label.setSize( label.getPreferredSize() );

label.setLocation(500, 500);

contentPane.add( label );

KeyboardAnimation animation = new KeyboardAnimation(label, 24);

animation.addAction("LEFT", -3, 0);

animation.addAction("RIGHT", 3, 0);

animation.addAction("UP", 0, -3);

animation.addAction("DOWN", 0, 3);

animation.addAction("control LEFT", -5, 0);

animation.addAction("V", 5, 5);

JLabel label2 = new JLabel( new ColorIcon(Color.GREEN, 40, 40) );

label2.setSize( label2.getPreferredSize() );

label2.setLocation(100, 100);

contentPane.add( label2 );

KeyboardAnimation animation2 = new KeyboardAnimation(label2, 24);

animation2.addAction("A", -3, 0);

animation2.addAction("D", 3, 0);

animation2.addAction("W", 0, -3);

animation2.addAction("S", 0, 3);

JFrame frame = new JFrame();

frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

frame.getContentPane().add(contentPane);

frame.setSize(600, 600);

frame.setLocationRelativeTo( null );

frame.setVisible(true);

}

static class ColorIcon implements Icon

{

private Color color;

private int width;

private int height;

public ColorIcon(Color color, int width, int height)

{

this.color = color;

this.width = width;

this.height = height;

}

public int getIconWidth()

{

return width;

}

public int getIconHeight()

{

return height;

}

public void paintIcon(Component c, Graphics g, int x, int y)

{

g.setColor(color);

g.fillRect(x, y, width, height);

}

}

}