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package javax.swing;

import java.awt.*;
import java.awt.image.*;
import sun.awt.image.MultiResolutionCachedImage;

An image filter that "disables" an image by turning it into a grayscale image, and brightening the pixels in the image. Used by buttons to create an image for a disabled button.
Author: Jeff Dinkins, Tom Ball, Jim Graham
Since:1.2
/** * An image filter that "disables" an image by turning * it into a grayscale image, and brightening the pixels * in the image. Used by buttons to create an image for * a disabled button. * * @author Jeff Dinkins * @author Tom Ball * @author Jim Graham * @since 1.2 */
public class GrayFilter extends RGBImageFilter { private boolean brighter; private int percent;
Creates a disabled image
Params:
  • i – an Image to be created as disabled
Returns: the new grayscale image created from i
/** * Creates a disabled image * * @param i an {@code Image} to be created as disabled * @return the new grayscale image created from {@code i} */
public static Image createDisabledImage(Image i) { if (i instanceof MultiResolutionImage) { return MultiResolutionCachedImage .map((MultiResolutionImage) i, (img) -> createDisabledImageImpl(img)); } return createDisabledImageImpl(i); } private static Image createDisabledImageImpl(Image i) { GrayFilter filter = new GrayFilter(true, 50); ImageProducer prod = new FilteredImageSource(i.getSource(), filter); Image grayImage = Toolkit.getDefaultToolkit().createImage(prod); return grayImage; }
Constructs a GrayFilter object that filters a color image to a grayscale image. Used by buttons to create disabled ("grayed out") button images.
Params:
  • b – a boolean -- true if the pixels should be brightened
  • p – an int in the range 0..100 that determines the percentage of gray, where 100 is the darkest gray, and 0 is the lightest
/** * Constructs a GrayFilter object that filters a color image to a * grayscale image. Used by buttons to create disabled ("grayed out") * button images. * * @param b a boolean -- true if the pixels should be brightened * @param p an int in the range 0..100 that determines the percentage * of gray, where 100 is the darkest gray, and 0 is the lightest */
public GrayFilter(boolean b, int p) { brighter = b; percent = p; // canFilterIndexColorModel indicates whether or not it is acceptable // to apply the color filtering of the filterRGB method to the color // table entries of an IndexColorModel object in lieu of pixel by pixel // filtering. canFilterIndexColorModel = true; }
Overrides RGBImageFilter.filterRGB.
/** * Overrides <code>RGBImageFilter.filterRGB</code>. */
public int filterRGB(int x, int y, int rgb) { // Use NTSC conversion formula. int gray = (int)((0.30 * ((rgb >> 16) & 0xff) + 0.59 * ((rgb >> 8) & 0xff) + 0.11 * (rgb & 0xff)) / 3); if (brighter) { gray = (255 - ((255 - gray) * (100 - percent) / 100)); } else { gray = (gray * (100 - percent) / 100); } if (gray < 0) gray = 0; if (gray > 255) gray = 255; return (rgb & 0xff000000) | (gray << 16) | (gray << 8) | (gray << 0); } }