SpriteSheetAnim.java

package anim;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.io.IOException;
import java.net.URL;

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

@SuppressWarnings("serial")
public class SpriteSheetAnim extends JPanel {

	public Image imgSprite;
	public URL imgUrl;
	public static SpriteSheetAnim walkingGirl;
	public int ROWS = 4, COLUMNS = 4;
	public int imgWidth, imgHeight;
	public int spritePosition = 0;

	public SpriteSheetAnim() {
		imgUrl = getClass().getClassLoader().getResource("spritesheet.png");
		if (imgUrl != null) {

			try {
				imgSprite = ImageIO.read(imgUrl);
			} catch (IOException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
		} else {
			System.err.println("null image url");
		}
		imgWidth = imgSprite.getWidth(null) / COLUMNS;
		imgHeight = imgSprite.getHeight(null) / ROWS;

		Thread animationThread = new Thread() {
			@Override
			public void run() {
				while (true) {
					// System.out.println("Frame number : "+spritePosition);
					update();
					repaint();
					try {
						Thread.sleep(50);
					} catch (Exception e) {

					}
				}
			}
		};
		animationThread.start();
		this.setPreferredSize(new Dimension(imgWidth, imgHeight));
	}

	public int getSpriteX(int position) {

		switch (position) {

			//TODO get values in a better way | using an algorithm
			case 0 :
			case 4 :
			case 8 :
			case 12 :
				return 0 * imgWidth;
			case 1 :
			case 5 :
			case 9 :
			case 13 :
				return 1 * imgWidth;
			case 2 :
			case 6 :
			case 10 :
			case 14 :
				return 2 * imgWidth;
			case 3 :
			case 7 :
			case 11 :
			case 15 :
				return 3 * imgWidth;

			default :
				return 0;
		}

	}

	public int getSpriteY(int position) {
		switch (position) {
			//TODO get values in a better way |using an algorithm

			case 0 :
			case 1 :
			case 2 :
			case 3 :
				return 0 * imgHeight;

			case 4 :
			case 5 :
			case 6 :
			case 7 :
				return 1 * imgHeight;

			case 8 :
			case 9 :
			case 10 :
			case 11 :
				return 2 * imgHeight;

			case 12 :
			case 13 :
			case 14 :
			case 15 :
				return 3 * imgHeight;

			default :
				return 0;
		}

	}

	@Override
	protected void paintComponent(Graphics graphics) {

		graphics.drawImage(imgSprite,
				0, // destination startX
				0, // destination startY

				imgWidth, // img width at destination
				imgHeight, // img height at destination

				getSpriteX(spritePosition), // source start x
				getSpriteY(spritePosition), // source start y

				getSpriteX(spritePosition) + imgWidth, // source end x
				getSpriteY(spritePosition) + imgHeight, // source end y

				null);

	}
	private void update() {

		spritePosition++;
		if (spritePosition > 15) {
			spritePosition = 0;
		}
	}
	public static void main(String[] args) {

		SwingUtilities.invokeLater(new Runnable() {

			public void run() {
				// TODO Auto-generated method stub
				JFrame window = new JFrame("Walking Girl");
				walkingGirl = new SpriteSheetAnim();
				window.setContentPane(walkingGirl);
				window.pack();
				window.setAlwaysOnTop(true);
				window.setVisible(true);
				window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				window.setLocationRelativeTo(null);
			}
		});

	}


}