slideshow oxygen hackathon imageviewer

//2012-06-07 johnpfeiffer

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.Random;

import javax.imageio.ImageIO;

class ImageViewer extends Component
{
    private static final long serialVersionUID = 1L;
    private int numlocs = 2;
    private int numcells = numlocs * numlocs;
    private int[] cells;
    private BufferedImage bi;
    int w , h , cw , ch;

    public ImageViewer( URL imageSrc )
    {
        try
        {
            bi = ImageIO.read( imageSrc );
            w = bi.getWidth( null );
            h = bi.getHeight( null );
        } catch( IOException e )
        {
            System.out.println( "Image could not be read" );
            System.exit( 1 );
        }
        cw = w / numlocs;
        ch = h / numlocs;
        cells = new int[numcells];
        for( int i = 0 ; i < numcells ; i++ )
        {
            cells[i] = i;
        }
    }

    void jumble()
    {
        Random rand = new Random();
        int ri;
        for( int i = 0 ; i < numcells ; i++ )
        {
            while( ( ri = rand.nextInt( numlocs ) ) == i )
                ;

            int tmp = cells[i];
            cells[i] = cells[ri];
            cells[ri] = tmp;
        }
    }

    public Dimension getPreferredSize()
    {
        return new Dimension( w , h );
    }

    public void paint( Graphics g )
    {

        int dx , dy;
        for( int x = 0 ; x < numlocs ; x++ )
        {
            int sx = x * cw;
            for( int y = 0 ; y < numlocs ; y++ )
            {
                int sy = y * ch;
                int cell = cells[x * numlocs + y];
                dx = ( cell / numlocs ) * cw;
                dy = ( cell % numlocs ) * ch;
                g.drawImage( bi , dx , dy , dx + cw , dy + ch , sx , sy , sx + cw , sy
                        + ch , null );
            }
        }
    }
} // end class