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

public class MotionWithKeyListener extends KeyAdapter
{
	private Component component;
	private int deltaX;
	private int deltaY;

	public MotionWithKeyListener(Component component, int deltaX, int deltaY)
	{
		this.component = component;
		this.deltaX = deltaX;
		this.deltaY = deltaY;
	}

	//  Move the component to its new location. The component will stop
	//  moving when it reaches the bounds of its container

	public void move(int deltaX, int deltaY)
	{
		int componentWidth = component.getSize().width;
		int componentHeight = component.getSize().height;

		Dimension parentSize = component.getParent().getSize();
		int parentWidth  = parentSize.width;
		int parentHeight = parentSize.height;

		//  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);
	}

	@Override
	public void keyPressed(KeyEvent e)
	{
		if (e.getKeyCode() == KeyEvent.VK_LEFT)
			move(-deltaX, 0);
		else if (e.getKeyCode() == KeyEvent.VK_RIGHT)
			move(deltaX, 0);
		else if (e.getKeyCode() == KeyEvent.VK_UP)
			move(0, -deltaY);
		else if (e.getKeyCode() == KeyEvent.VK_DOWN)
			move(0, deltaY);
	}

	private static JButton addMotionSupport(Component component)
	{
		KeyListener keyListener = new MotionWithKeyListener(component, 3, 3);
		component.addKeyListener(keyListener);
		component.setFocusable(true);

		return new JButton("LEFT");
	}

	public static void main(String[] args)
	{
		EventQueue.invokeLater(new Runnable()
		{
			public void run()
			{
				//  Create a panel with a component to be moved

				JPanel content = new JPanel();
				content.setLayout(null);

				JLabel component = new JLabel( new ColorIcon(Color.BLUE, 40, 40) );
				component.setSize( component.getPreferredSize() );
				component.setLocation(100, 100);
				content.add(component);

				JButton left = addMotionSupport( component );

				JFrame.setDefaultLookAndFeelDecorated(true);
				JFrame frame = new JFrame("Motion With Key Listener");
				frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
				frame.add( content );
				frame.add(left, BorderLayout.SOUTH);
				frame.setSize(600, 600);
				frame.setLocationByPlatform( true );
				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);
		}
	}
}