RGB Gray Filter
/*
* Copyright (c) 2001-2009 JGoodies Karsten Lentzsch. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* o Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* o Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* o Neither the name of JGoodies Karsten Lentzsch nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.awt.Image;
import java.awt.image.*;
import javax.swing.GrayFilter;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
/**
* An image filter that turns an icon into a grayscale icon. Used by
* the JGoodies Windows and Plastic L&Fs to create a disabled icon.<p>
*
* The high-resolution gray filter can be disabled globally using
* {@link Options#setHiResGrayFilterEnabled(boolean)}; it is enabled by default.
* The global setting can be overridden per component by setting
* the client property key {@link Options#HI_RES_DISABLED_ICON_CLIENT_KEY}
* to <code>Boolean.FALSE</code>.<p>
*
* Thanks to Andrej Golovnin for suggesting a simpler filter formula.
*
* @author Karsten Lentzsch
* @version $Revision: 1.10 $
*/
public final class RGBGrayFilter extends RGBImageFilter {
/**
* Overrides default constructor; prevents instantiation.
*/
private RGBGrayFilter() {
canFilterIndexColorModel = true;
}
/**
* Returns an icon with a disabled appearance. This method is used
* to generate a disabled icon when one has not been specified.
*
* @param component the component that will display the icon, may be null.
* @param icon the icon to generate disabled icon from.
* @return disabled icon, or null if a suitable icon can not be generated.
*/
public static Icon getDisabledIcon(JComponent component, Icon icon) {
if ( (icon == null)
|| (component == null)
|| (icon.getIconWidth() == 0)
|| (icon.getIconHeight() == 0)) {
return null;
}
Image img;
if (icon instanceof ImageIcon) {
img = ((ImageIcon) icon).getImage();
} else {
img = new BufferedImage(
icon.getIconWidth(),
icon.getIconHeight(),
BufferedImage.TYPE_INT_ARGB);
icon.paintIcon(component, img.getGraphics(), 0, 0);
}
ImageProducer producer =
new FilteredImageSource(img.getSource(), new RGBGrayFilter());
return new ImageIcon(component.createImage(producer));
}
/**
* Converts a single input pixel in the default RGB ColorModel to a single
* gray pixel.
*
* @param x the horizontal pixel coordinate
* @param y the vertical pixel coordinate
* @param rgb the integer pixel representation in the default RGB color model
* @return a gray pixel in the default RGB color model.
*
* @see ColorModel#getRGBdefault
* @see #filterRGBPixels
*/
public int filterRGB(int x, int y, int rgb) {
// Find the average of red, green, and blue.
float avg = (((rgb >> 16) & 0xff) / 255f +
((rgb >> 8) & 0xff) / 255f +
(rgb & 0xff) / 255f) / 3;
// Pull out the alpha channel.
float alpha = (((rgb >> 24) & 0xff) / 255f);
// Calculate the average.
// Sun's formula: Math.min(1.0f, (1f - avg) / (100.0f / 35.0f) + avg);
// The following formula uses less operations and hence is faster.
avg = Math.min(1.0f, 0.35f + 0.65f * avg);
// Convert back into RGB.
return (int) (alpha * 255f) << 24 |
(int) (avg * 255f) << 16 |
(int) (avg * 255f) << 8 |
(int) (avg * 255f);
}
}
Related examples in the same category
