/*
 * Beanfabrics Framework Copyright (C) by Michael Karneim, beanfabrics.org
 * Use is subject to license terms. See license.txt.
 */
package org.beanfabrics.swt.samples.filebrowser;

import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.DirectColorModel;
import java.awt.image.IndexColorModel;
import java.awt.image.WritableRaster;

import javax.swing.Icon;

import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.PaletteData;
import org.eclipse.swt.graphics.RGB;

/**
 * Converter for converting AWT/Swing Images and Icons to SWT ImageData objects.
 * 
 * @author Michael Karneim
 */
public class ImageConverter {

    public ImageData convertToImageData(Icon icon) {
        return convertToImageData(convertToBufferedImage(icon));
    }

    private BufferedImage convertToBufferedImage(Icon icon) {
        int w = icon.getIconWidth();
        int h = icon.getIconHeight();
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice gd = ge.getDefaultScreenDevice();
        GraphicsConfiguration gc = gd.getDefaultConfiguration();
        BufferedImage image = gc.createCompatibleImage(w, h, Transparency.TRANSLUCENT);
        Graphics2D g2D = image.createGraphics();
        icon.paintIcon(null, g2D, 0, 0);
        g2D.dispose();

        return image;
    }

    public ImageData convertToImageData(BufferedImage bufferedImage) {
        if (bufferedImage.getColorModel() instanceof DirectColorModel) {
            DirectColorModel colorModel = (DirectColorModel)bufferedImage.getColorModel();
            PaletteData palette = new PaletteData(colorModel.getRedMask(), colorModel.getGreenMask(), colorModel.getBlueMask());

            ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette);
            data.alphaData = new byte[bufferedImage.getWidth() * bufferedImage.getHeight()];

            WritableRaster alphaRaster = bufferedImage.getAlphaRaster();
            for (int y = 0; y < data.height; y++) {
                for (int x = 0; x < data.width; x++) {
                    int rgb = bufferedImage.getRGB(x, y);
                    int alpha = alphaRaster.getSample(x, y, 0);
                    data.alphaData[y * data.width + x] = (byte)alpha;
                    int pixel = palette.getPixel(new RGB((rgb >> 16) & 0xFF, (rgb >> 8) & 0xFF, rgb & 0xFF));
                    data.setPixel(x, y, pixel);
                }
            }

            return data;
        } else if (bufferedImage.getColorModel() instanceof IndexColorModel) {
            IndexColorModel colorModel = (IndexColorModel)bufferedImage.getColorModel();
            int size = colorModel.getMapSize();
            byte[] reds = new byte[size];
            byte[] greens = new byte[size];
            byte[] blues = new byte[size];
            colorModel.getReds(reds);
            colorModel.getGreens(greens);
            colorModel.getBlues(blues);
            RGB[] rgbs = new RGB[size];
            for (int i = 0; i < rgbs.length; i++) {
                rgbs[i] = new RGB(reds[i] & 0xFF, greens[i] & 0xFF, blues[i] & 0xFF);
            }
            PaletteData palette = new PaletteData(rgbs);
            ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette);
            data.transparentPixel = colorModel.getTransparentPixel();
            WritableRaster raster = bufferedImage.getRaster();
            int[] pixelArray = new int[1];
            for (int y = 0; y < data.height; y++) {
                for (int x = 0; x < data.width; x++) {
                    raster.getPixel(x, y, pixelArray);
                    data.setPixel(x, y, pixelArray[0]);
                }
            }
            return data;
        }
        return null;
    }

}