org.eclipse.swt.snippets.Snippet139.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet139.java

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/*******************************************************************************
 * Copyright (c) 2000, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.snippets;

/*
 * This snippet was adapted from org.eclipse.draw2d.ImageUtilities in
 * http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.draw2d/?cvsroot=Tools_Project
 * by Pratik Shah.
 *
 * example snippet: rotate and flip an image
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

public class Snippet139 {

    static ImageData rotate(ImageData srcData, int direction) {
        int bytesPerPixel = srcData.bytesPerLine / srcData.width;
        int destBytesPerLine = (direction == SWT.DOWN) ? srcData.width * bytesPerPixel
                : srcData.height * bytesPerPixel;
        byte[] newData = new byte[(direction == SWT.DOWN) ? srcData.height * destBytesPerLine
                : srcData.width * destBytesPerLine];
        int width = 0, height = 0;
        for (int srcY = 0; srcY < srcData.height; srcY++) {
            for (int srcX = 0; srcX < srcData.width; srcX++) {
                int destX = 0, destY = 0, destIndex = 0, srcIndex = 0;
                switch (direction) {
                case SWT.LEFT: // left 90 degrees
                    destX = srcY;
                    destY = srcData.width - srcX - 1;
                    width = srcData.height;
                    height = srcData.width;
                    break;
                case SWT.RIGHT: // right 90 degrees
                    destX = srcData.height - srcY - 1;
                    destY = srcX;
                    width = srcData.height;
                    height = srcData.width;
                    break;
                case SWT.DOWN: // 180 degrees
                    destX = srcData.width - srcX - 1;
                    destY = srcData.height - srcY - 1;
                    width = srcData.width;
                    height = srcData.height;
                    break;
                }
                destIndex = (destY * destBytesPerLine) + (destX * bytesPerPixel);
                srcIndex = (srcY * srcData.bytesPerLine) + (srcX * bytesPerPixel);
                System.arraycopy(srcData.data, srcIndex, newData, destIndex, bytesPerPixel);
            }
        }
        // destBytesPerLine is used as scanlinePad to ensure that no padding is required
        return new ImageData(width, height, srcData.depth, srcData.palette, srcData.scanlinePad, newData);
    }

    static ImageData flip(ImageData srcData, boolean vertical) {
        int bytesPerPixel = srcData.bytesPerLine / srcData.width;
        int destBytesPerLine = srcData.width * bytesPerPixel;
        byte[] newData = new byte[srcData.data.length];
        for (int srcY = 0; srcY < srcData.height; srcY++) {
            for (int srcX = 0; srcX < srcData.width; srcX++) {
                int destX = 0, destY = 0, destIndex = 0, srcIndex = 0;
                if (vertical) {
                    destX = srcX;
                    destY = srcData.height - srcY - 1;
                } else {
                    destX = srcData.width - srcX - 1;
                    destY = srcY;
                }
                destIndex = (destY * destBytesPerLine) + (destX * bytesPerPixel);
                srcIndex = (srcY * srcData.bytesPerLine) + (srcX * bytesPerPixel);
                System.arraycopy(srcData.data, srcIndex, newData, destIndex, bytesPerPixel);
            }
        }
        // destBytesPerLine is used as scanlinePad to ensure that no padding is required
        return new ImageData(srcData.width, srcData.height, srcData.depth, srcData.palette, srcData.scanlinePad,
                newData);
    }

    public static void main(String[] args) {
        Display display = new Display();

        // create an image with the word "hello" on it
        final Image image0 = new Image(display, 50, 30);
        GC gc = new GC(image0);
        gc.setBackground(display.getSystemColor(SWT.COLOR_RED));
        gc.fillRectangle(image0.getBounds());
        gc.drawString("hello", 5, 5, true);
        gc.dispose();

        ImageData data = image0.getImageData();
        // rotate and flip this image
        final Image image1 = new Image(display, rotate(data, SWT.LEFT));
        final Image image2 = new Image(display, rotate(data, SWT.RIGHT));
        final Image image3 = new Image(display, rotate(data, SWT.DOWN));
        final Image image4 = new Image(display, flip(data, true));
        final Image image5 = new Image(display, flip(data, false));

        Shell shell = new Shell(display);
        shell.setText("Snippet 139");
        // draw the results on the shell
        shell.addPaintListener(e -> {
            e.gc.drawText("Original Image:", 10, 10, true);
            e.gc.drawImage(image0, 10, 40);
            e.gc.drawText("Left, Right, 180:", 10, 80, true);
            e.gc.drawImage(image1, 10, 110);
            e.gc.drawImage(image2, 50, 110);
            e.gc.drawImage(image3, 90, 110);
            e.gc.drawText("Flipped Vertical, Horizontal:", 10, 170, true);
            e.gc.drawImage(image4, 10, 200);
            e.gc.drawImage(image5, 70, 200);
        });
        shell.setSize(300, 300);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        image0.dispose();
        image1.dispose();
        image2.dispose();
        image3.dispose();
        image4.dispose();
        image5.dispose();
        display.dispose();
    }
}