[Java] Coordonnées, zoom, échelle : intéract°

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 * Created on 03-mai-07
 * 
 * @author:HackTrack
 */

public class ZoomPanel extends JPanel implements MouseWheelListener {
	private BufferedImage sourceImage;

	private int sourceImageWidth;

	private int sourceImageHeight;

	private Image scaledImage;
	private double zoom = 1d;

	public ZoomPanel() {
		super();
		initializePanel();
	}

	private void initializePanel() {
		setPreferredSize(new Dimension(640, 480));
		try {
			sourceImage = ImageIO.read(new File("F:/testBG.jpg"));
			sourceImageWidth = sourceImage.getWidth();
			sourceImageHeight=sourceImage.getHeight();
			addMouseWheelListener(this);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public void paint(Graphics g){
		
		int width = (int)(sourceImageWidth*zoom);
		int height = (int)(sourceImageHeight*zoom);
		Image img = sourceImage.getScaledInstance(width, height, Image.SCALE_SMOOTH);
		g.drawImage(img,0,0,null);
	}

	public void mouseWheelMoved(MouseWheelEvent e) {
		int wheelRotation =e.getWheelRotation(); 
		if(zoom>1){
			zoom+=wheelRotation;
		}else if(zoom==1){
			zoom=(wheelRotation==1?zoom+wheelRotation:0.5);
		}else if(zoom<1){
			zoom/=(wheelRotation*2);
		}
		repaint();
	}

	public static void main(String[] args) {
		JFrame demo = new JFrame();
		demo.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		demo.add(new ZoomPanel());
		demo.pack();
		demo.setVisible(true);
	}

}