Java Tutorial/SWT/SWT Color

Change hue, saturation and brightness of a color

/*******************************************************************************
 * Copyright (c) 2000, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
/*
 * Change hue, saturation and brightness of a color
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.2
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.PaletteData;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
public class ColorChangeHueSaturationBrightness {
  public static void main(String[] args) {
    PaletteData palette = new PaletteData(0xff, 0xff00, 0xff0000);
    // ImageData showing variations of hue
    ImageData hueData = new ImageData(360, 100, 24, palette);
    float hue = 0;
    for (int x = 0; x < hueData.width; x++) {
      for (int y = 0; y < hueData.height; y++) {
        int pixel = palette.getPixel(new RGB(hue, 1f, 1f));
        hueData.setPixel(x, y, pixel);
      }
      hue += 360f / hueData.width;
    }
    // ImageData showing saturation on x axis and brightness on y axis
    ImageData saturationBrightnessData = new ImageData(360, 360, 24, palette);
    float saturation = 0f;
    float brightness = 1f;
    for (int x = 0; x < saturationBrightnessData.width; x++) {
      brightness = 1f;
      for (int y = 0; y < saturationBrightnessData.height; y++) {
        int pixel = palette.getPixel(new RGB(360f, saturation, brightness));
        saturationBrightnessData.setPixel(x, y, pixel);
        brightness -= 1f / saturationBrightnessData.height;
      }
      saturation += 1f / saturationBrightnessData.width;
    }
    Display display = new Display();
    Image hueImage = new Image(display, hueData);
    Image saturationImage = new Image(display, saturationBrightnessData);
    Shell shell = new Shell(display);
    shell.setText("Hue, Saturation, Brightness");
    GridLayout gridLayout = new GridLayout(2, false);
    gridLayout.verticalSpacing = 10;
    gridLayout.marginWidth = gridLayout.marginHeight = 16;
    shell.setLayout(gridLayout);
    Label label = new Label(shell, SWT.CENTER);
    label.setImage(hueImage);
    GridData data = new GridData(SWT.RIGHT, SWT.CENTER, false, false, 2, 1);
    label.setLayoutData(data);
    label = new Label(shell, SWT.CENTER); // spacer
    label = new Label(shell, SWT.CENTER);
    label.setText("Hue");
    data = new GridData(SWT.CENTER, SWT.CENTER, false, false);
    label.setLayoutData(data);
    label = new Label(shell, SWT.CENTER); // spacer
    data = new GridData(SWT.CENTER, SWT.CENTER, false, false, 2, 1);
    label.setLayoutData(data);
    label = new Label(shell, SWT.LEFT);
    label.setText("Brightness");
    data = new GridData(SWT.LEFT, SWT.CENTER, false, false);
    label.setLayoutData(data);
    label = new Label(shell, SWT.CENTER);
    label.setImage(saturationImage);
    data = new GridData(SWT.CENTER, SWT.CENTER, false, false);
    label.setLayoutData(data);
    label = new Label(shell, SWT.CENTER); // spacer
    label = new Label(shell, SWT.CENTER);
    label.setText("Saturation");
    data = new GridData(SWT.CENTER, SWT.CENTER, false, false);
    label.setLayoutData(data);
    shell.pack();
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    hueImage.dispose();
    saturationImage.dispose();
    display.dispose();
  }
}

Create Transparent Color

/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
/* 
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.PaletteData;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class ColorTransparentCreate {
  public static void main(String[] args) {
    final Display display = new Display();
    Shell shell = new Shell(display);
    shell.setBounds(10, 10, 200, 200);
    // create a cursor with a transparent image
    Color white = display.getSystemColor(SWT.COLOR_WHITE);
    Color black = display.getSystemColor(SWT.COLOR_BLACK);
    PaletteData palette = new PaletteData(new RGB[] { white.getRGB(), black.getRGB() });
    final ImageData sourceData = new ImageData(30, 30, 1, palette);
    sourceData.transparentPixel = 0;
    Canvas canvas = new Canvas(shell, SWT.BORDER);
    canvas.setBounds(10, 50, 150, 100);
    
    canvas.addPaintListener(new PaintListener() {
      public void paintControl(PaintEvent e) {
        e.gc.drawString("hide Cursor here", 10, 10);
        e.gc.drawImage(new Image(display, sourceData), 0, 0);
      }
    });
    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}