/*
* Copyright (c) 1997, 1998, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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*
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package javax.swing;
import java.awt.*;
import java.awt.image.*;
/**
* 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
*/
public class GrayFilter extends RGBImageFilter {
private boolean brighter;
private int percent;
/**
* Creates a disabled image
*/
public static Image createDisabledImage (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.
*
* @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 <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);
}
}