//
// another example of the Java AWT, showing loading and display of
//      an image.
// see class definition for details.
//
// (applet version)
//
import java.awt.* ;
import java.awt.image.* ;
import java.io.* ;
import java.applet.* ;
import java.net.* ;

//
// a ShowImageApplet object is an Applet that displays an image
//      loaded from a file (GIF and JPEG formats are supported).
//
public class ShowImageApplet extends Applet {

        private Image frameImage ;

	private int imageWidth = -1 ;
	private int imageHeight = -1 ;

	public void init() {

		// start loading image 
		System.out.println("init called") ;
		String imageName = getParameter("image") ;
		System.out.println("image name = " + imageName) ;
		URL codeBase = getCodeBase() ;
		System.out.println("code base = " + codeBase) ;
		frameImage = getImage(getCodeBase(),
				getParameter("image")) ;

		if (frameImage == null) {
			// "should" never happen, but may if we
			// trip over a browser bug
			System.out.println(
				"Something is wrong -- " +
				"getImage() returned null") ;
			System.exit(-1) ;
		}

                System.out.println("loading image ....") ;

                // wait for completion.
                waitForImage(frameImage) ;
                System.out.println("done") ;
        }

        // waits for image to finish loading.
        private void waitForImage(Image im) {
                MediaTracker tracker = new MediaTracker(this) ;
                // add desired image to list of things the
                //      MediaTracker is tracking, with id = 0.
                tracker.addImage(im, 0) ;
                try {
                        // wait for loading of image we just
                        //      added to MediaTracker's list.
                        tracker.waitForID(0) ;
                } catch(InterruptedException e) { }
        }

        // creates onscreen image by scaling image from file.
        public void paint(Graphics g) {

                System.out.println("paint called") ;

                if (frameImage != null) {

                        // get size of applet area
                        Dimension appletDims = getSize() ;

                	int w = frameImage.getWidth(this) ;
                	int h = frameImage.getHeight(this) ;

			int xOffset = 
				(appletDims.width - w) / 2 ;
			int yOffset =
				(appletDims.height - h) / 2 ;

			System.out.println("offsets for image = "
				+ xOffset + ", " + yOffset) ;

                        // draw image
                        g.drawImage(frameImage, xOffset, yOffset, this) ;
                }
        }

        // updates onscreen image (no need to clear first, just paint).
        public void update(Graphics g) {
                System.out.println("update called") ;
                paint(g) ;
        }
}