FilteredIconFactory.java

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 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
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package org.apache.cayenne.swing.components.image;

import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageProducer;
import java.awt.image.RGBImageFilter;
import javax.swing.Icon;
import javax.swing.JComponent;
import javax.swing.JPanel;
import javax.swing.UIManager;

import sun.swing.ImageIconUIResource;

/**
 * @since 4.0
 */
public class FilteredIconFactory {

    private static final JComponent DUMMY = new JPanel();

    public enum FilterType {
        DISABLE     (new DisabledFilter()),
        SELECTION   (new SelectionFilter()),
        WHITE       (new ColorFilter(0xFFFFFF)),
        GREEN       (new ColorFilter(0x65A91B)),
        VIOLET      (new ColorFilter(0xAD78DD)),
        BLUE        (new ColorFilter(0x53A3D6)),
        GRAY        (new ColorFilter(0x434343));

        private final RGBImageFilter filter;

        FilterType(RGBImageFilter filter) {
            this.filter = filter;
        }
    }

    static public Icon createDisabledIcon(Icon icon) {
        return createIcon(icon, FilterType.DISABLE);
    }

    static public Icon createIcon(Icon icon, FilterType filterType) {
        if (icon != null && icon.getIconWidth() > 0 && icon.getIconHeight() > 0) {
            BufferedImage img = new BufferedImage(icon.getIconWidth(), icon.getIconWidth(), BufferedImage.TYPE_INT_ARGB);
            icon.paintIcon(DUMMY, img.getGraphics(), 0, 0);
            ImageProducer producer = new FilteredImageSource(img.getSource(), filterType.filter);
            Image resultImage = DUMMY.createImage(producer);
            return new ImageIconUIResource(resultImage);
        }
        return null;
    }

    static class ColorFilter extends RGBImageFilter {

        private final int color;

        ColorFilter(int color) {
            canFilterIndexColorModel = true;
            this.color = color;
        }

        public int filterRGB(int x, int y, int argb) {
            int alpha = (argb >> 24) & 0xFF;
            return (alpha << 24) | color;
        }
    }

    static class SelectionFilter extends ColorFilter {
        SelectionFilter() {
            super(UIManager.getColor("Tree.selectionForeground").getRGB() & 0x00FFFFFF);
        }
    }

    static class DisabledFilter extends RGBImageFilter {

        DisabledFilter() {
            canFilterIndexColorModel = true;
        }

        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;
            // calc the average
            avg = Math.min(1.0f, (1f - avg)/(100.0f/35.0f) + avg);
            // turn back into argb
            return  (int)(alpha * 120f) << 24 |
                    (int)(avg   * 255f) << 16 |
                    (int)(avg   * 255f) <<  8 |
                    (int)(avg   * 255f);
        }
    }
}