1/* 2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25package javax.swing; 26 27import java.awt.*; 28import java.awt.image.*; 29import sun.awt.image.MultiResolutionCachedImage; 30 31/** 32 * An image filter that "disables" an image by turning 33 * it into a grayscale image, and brightening the pixels 34 * in the image. Used by buttons to create an image for 35 * a disabled button. 36 * 37 * @author Jeff Dinkins 38 * @author Tom Ball 39 * @author Jim Graham 40 * @since 1.2 41 */ 42public class GrayFilter extends RGBImageFilter { 43 private boolean brighter; 44 private int percent; 45 46 /** 47 * Creates a disabled image 48 * 49 * @param i an {@code Image} to be created as disabled 50 * @return the new grayscale image created from {@code i} 51 */ 52 public static Image createDisabledImage(Image i) { 53 if (i instanceof MultiResolutionImage) { 54 return MultiResolutionCachedImage 55 .map((MultiResolutionImage) i, 56 (img) -> createDisabledImageImpl(img)); 57 } 58 return createDisabledImageImpl(i); 59 } 60 61 private static Image createDisabledImageImpl(Image i) { 62 GrayFilter filter = new GrayFilter(true, 50); 63 ImageProducer prod = new FilteredImageSource(i.getSource(), filter); 64 Image grayImage = Toolkit.getDefaultToolkit().createImage(prod); 65 return grayImage; 66 } 67 68 /** 69 * Constructs a GrayFilter object that filters a color image to a 70 * grayscale image. Used by buttons to create disabled ("grayed out") 71 * button images. 72 * 73 * @param b a boolean -- true if the pixels should be brightened 74 * @param p an int in the range 0..100 that determines the percentage 75 * of gray, where 100 is the darkest gray, and 0 is the lightest 76 */ 77 public GrayFilter(boolean b, int p) { 78 brighter = b; 79 percent = p; 80 81 // canFilterIndexColorModel indicates whether or not it is acceptable 82 // to apply the color filtering of the filterRGB method to the color 83 // table entries of an IndexColorModel object in lieu of pixel by pixel 84 // filtering. 85 canFilterIndexColorModel = true; 86 } 87 88 /** 89 * Overrides <code>RGBImageFilter.filterRGB</code>. 90 */ 91 public int filterRGB(int x, int y, int rgb) { 92 // Use NTSC conversion formula. 93 int gray = (int)((0.30 * ((rgb >> 16) & 0xff) + 94 0.59 * ((rgb >> 8) & 0xff) + 95 0.11 * (rgb & 0xff)) / 3); 96 97 if (brighter) { 98 gray = (255 - ((255 - gray) * (100 - percent) / 100)); 99 } else { 100 gray = (gray * (100 - percent) / 100); 101 } 102 103 if (gray < 0) gray = 0; 104 if (gray > 255) gray = 255; 105 return (rgb & 0xff000000) | (gray << 16) | (gray << 8) | (gray << 0); 106 } 107} 108