MainClass.java Source code

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Here is the source code for MainClass.java

Source

// This example is from the book _Java AWT Reference_ by John Zukowski.
// Written by John Zukowski.  Copyright (c) 1997 O'Reilly & Associates.
// You may study, use, modify, and distribute this example for any purpose.
// This example is provided WITHOUT WARRANTY either expressed or
import java.applet.Applet;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.image.ImageObserver;
import java.awt.image.MemoryImageSource;
import java.awt.image.PixelGrabber;

public class MainClass extends Applet {
    Image i, j, k, l;

    public void init() {
        MediaTracker mt = new MediaTracker(this);
        i = getImage(getDocumentBase(), "ora-icon.gif");
        mt.addImage(i, 0);
        try {
            mt.waitForAll();
            int width = i.getWidth(this);
            int height = i.getHeight(this);
            int pixels[] = new int[width * height];
            PixelGrabber pg = new PixelGrabber(i, 0, 0, width, height, pixels, 0, width);
            if (pg.grabPixels() && ((pg.status() & ImageObserver.ALLBITS) != 0)) {
                j = createImage(
                        new MemoryImageSource(width, height, rowFlipPixels(pixels, width, height), 0, width));
                k = createImage(
                        new MemoryImageSource(width, height, colFlipPixels(pixels, width, height), 0, width));
                l = createImage(
                        new MemoryImageSource(height, width, rot90Pixels(pixels, width, height), 0, height));
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public void paint(Graphics g) {
        g.drawImage(i, 10, 10, this); // regular
        if (j != null)
            g.drawImage(j, 150, 10, this); // rowFlip
        if (k != null)
            g.drawImage(k, 10, 60, this); // colFlip
        if (l != null)
            g.drawImage(l, 150, 60, this); // rot90
    }

    private int[] rowFlipPixels(int pixels[], int width, int height) {
        int newPixels[] = null;
        if ((width * height) == pixels.length) {
            newPixels = new int[width * height];
            int newIndex = 0;
            for (int y = height - 1; y >= 0; y--)
                for (int x = width - 1; x >= 0; x--)
                    newPixels[newIndex++] = pixels[y * width + x];
        }
        return newPixels;
    }

    private int[] colFlipPixels(int pixels[], int width, int height) {
        int newPixels[] = null;
        if ((width * height) == pixels.length) {
            newPixels = new int[width * height];
            int newIndex = 0;
            for (int y = 0; y < height; y++)
                for (int x = width - 1; x >= 0; x--)
                    newPixels[newIndex++] = pixels[y * width + x];
        }
        return newPixels;
    }

    private int[] rot90Pixels(int pixels[], int width, int height) {
        int newPixels[] = null;
        if ((width * height) == pixels.length) {
            newPixels = new int[width * height];
            int newIndex = 0;
            for (int x = width - 1; x >= 0; x--)
                for (int y = 0; y < height; y++)
                    newPixels[newIndex++] = pixels[y * width + x];
        }
        return newPixels;
    }
}