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

//
// a ShowImageWithObserver object is a DrawingFrame that displays an 
//	image loaded from a URL (GIF and JPEG formats are supported).
//      the initial size of the display is just big enough to
//      contain the image; if the window is resized, the image is
//      scaled to fit.  in additional, the object has an ImageObserver
//	that reports on progress in loading/scaling the image.
//
class ShowImageWithObserver extends DrawingFrame 
		implements ImageObserver {

        private Image frameImage ;

	private boolean initialSizesSet = false ;

        ShowImageWithObserver(URL imageURL) {
                super("ShowImageWithObserver") ;

                // start loading image.
                frameImage = getToolkit().getImage(imageURL) ;

		// set initial size of frame and display
                setDrawingSize(new Dimension(200, 100)) ;
                show() ;
        }

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

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

		if (!initialSizesSet)
		{
                	int w = frameImage.getWidth(this) ;
                	int h = frameImage.getHeight(this) ;
			if ((w > 0) && (h > 0)) {
				setDrawingSize(
					new Dimension(w, h)) ;
				initialSizesSet = true ;
				System.out.println("in paint:  " +
					"setting initial size = "
					+ w + " by " + h) ;
			}
		}

		if (frameImage == null) {
			System.out.println("in paint:  null image") ;
		}
		else {

                        // position origin to avoid frame borders.
                        translateDrawingArea(g) ;

                        // get size of frame, minus borders.
                        Dimension d = getDrawingSize() ;

			System.out.println("in paint:  " +
				"scaling to size = " +
				d.width + " by " + d.height) ;

                        // draw scaled version of image.
                        g.drawImage(frameImage, 0, 0, d.width, d.height,
                                this) ;
                }
        }
        // updates onscreen image (no need to clear first, just paint).
        public void update(Graphics g) {
                System.out.println("update called") ;
                paint(g) ;
        }


	// called as image is loaded, etc.
	public boolean imageUpdate(Image img, int flags,
		int x, int y, int width, int height)
	{
		System.out.println("imageUpdate called") ;
		if ((flags & HEIGHT) != 0)
		{
			System.out.println("imageUpdate called; " +
				"HEIGHT flag set, height = " + height) ;
		}
		if ((flags & WIDTH) != 0)
		{
			System.out.println("imageUpdate called; " +
				"WIDTH flag set, width = " + width) ;
		}
		if ((flags & PROPERTIES) != 0)
			System.out.println("imageUpdate called; " +
				"PROPERTIES flag set") ;
		if ((flags & SOMEBITS) != 0)
			System.out.println("imageUpdate called; " +
				"SOMEBITS flag set") ;
		if ((flags & ALLBITS) != 0)
			System.out.println("imageUpdate called; " +
				"ALLBITS flag set") ;
		if ((flags & ERROR) != 0) 
			System.out.println("imageUpdate called; " +
				"ERROR flag set") ;
		if ((flags & ABORT) != 0)
			System.out.println("imageUpdate called; " +
				"ABORT flag set") ;

		if (((flags & ALLBITS)==0) && 
				((flags & ABORT)==0)) {
			System.out.println(
				"imageUpdate returning true") ;
			return true ;
		}
		else {
			System.out.println(
				"imageUpdate returning false") ;
			repaint() ;
			return false ;
		}
	}

        //
        // ---- main ---------------------------------------------------
        //
        // command-line argument:  file from which to load image.
        //
        public static void main(String[] args) {

                if (args.length < 1) {
                        System.out.println("Argument is URL") ;
                        System.exit(-1) ;
                }

                URL u = null;
		try {
			u = new URL(args[0]) ;
  		} catch (MalformedURLException e) {
  			System.out.println("Bad URL " + args[0]) ;
  			System.out.println("Exception = " + e) ;
  			System.exit(-1) ;
  		}

                ShowImageWithObserver s = new ShowImageWithObserver(u) ;
        }
}