import java.awt.*;

/**
 * This "factory" class has a helper method for loading images more easily
 * from the disk.  It is an example of the Factory Method design pattern.
 * @author Marty Stepp
 * @version Spring 2011, 04-20-2011
 */
public class ImageFactory {
	/**
	 * Reads an image file from the hard disk and returns a corresponding
	 * Image object.  The image is guaranteed to be fully loaded upon return.
	 * @param filename The path name of the file containing the image to load
	 * @param panel the drawing panel on which the image will be displayed
	 * @pre filename != null
	 * @return the image loaded, or null if no image could be read
	 */
	public static Image loadImage(String filename, DrawingPanel panel) {
		Toolkit tk = Toolkit.getDefaultToolkit();
		Image img = tk.getImage(filename);
		
		// have to use media tracker to wait for image to actually load
		MediaTracker mt = new MediaTracker(panel);
		mt.addImage(img, 1);
		try {
			mt.waitForAll();
		} catch (InterruptedException e) {}
		
		return img;
	}
}