/**
 * The class ImagePainter implements a GUI component that displays
 * a GIF file.
 * @author Charlie McDowell
 */
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class ImagePainter extends JComponent {  

  /**
   * Constructs an ImagePainter for a specified GIF file.
   *
   * @param fileName the name of the file from which 
   *    to read the GIF image.
   */
    public ImagePainter(String fileName) {
	image = Toolkit.getDefaultToolkit().getImage(fileName);

	// the MediaTracker constructor wants an ImageObserver
	// all components implement ImageObserver so just use "this"
	MediaTracker tracker = new MediaTracker(this);

	// you can call addImage more times to track several images
	// with this one MediaTracker
	tracker.addImage(image, 0/*user selected id to identify the image*/);

	// you can also use waitForId(idNum) to wait for a specific image
	// this idNum is the same one passed in the addImage() call
	try { tracker.waitForAll(); }
	catch (InterruptedException e) {}
    }
   
  /**
   * Paint the image to fill the component.
   *
   * @param g the Graphics object to paint on.
   */
    public void paint(Graphics g) {
	g.drawImage(image, 0, 0, this);
    }

  /**
   * Make the component just big enough to hold the image.
   *
   * @return the dimensions of the image
   */
    public Dimension getMinimumSize() {
	// size the component to just fit the image
	return new Dimension(image.getWidth(this), image.getHeight(this));
    }

  /**
   * The preferred size is the same as the minimum size.
   *
   * @return the dimensions of the image
   */
    public Dimension getPreferredSize() {
	return getMinimumSize();
    }

    private Image image;
}