1 files changed, 205 insertions, 0 deletions
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/PaletteData.java b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/PaletteData.java
new file mode 100755
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+++ b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/PaletteData.java
@@ -0,0 +1,205 @@
+package org.eclipse.swt.graphics;
+
+/*
+ * Licensed Materials - Property of IBM,
+ * (c) Copyright IBM Corp. 1998, 2001  All Rights Reserved
+ */
+
+import org.eclipse.swt.*;
+
+/**
+ * Instances of this class describe the color data used by an image.
+ * <p>
+ * Depending on the depth of the image, the PaletteData can take one
+ * of two forms, indicated by the isDirect field:
+ * </p>
+ * <dl>
+ * <dt>
+ * <em>isDirect is false</em>
+ * </dt>
+ * <dd>
+ * If isDirect is <code>false</code>, this palette is an indexed
+ * palette which maps pixel values to RGBs. The actual RGB values
+ * may be retrieved by using the getRGBs() method.
+ * </dd>
+ * <dt>
+ * <em>isDirect is true</em>
+ * </dt>
+ * <dd>
+ * If isDirect is <code>true</code>, this palette is a direct color
+ * palette. Instead of containing RGB values, it contains red,
+ * green and blue mask and shift information which indicates how
+ * the color components may be extracted from a given pixel.
+ * This means that the RGB value is actually encoded in the pixel value.
+ * <p>
+ * In this case, the shift data is the number of bits required to shift
+ * the RGB value to the left in order to align the high bit of the
+ * corresponding mask with the high bit of the first byte. This number
+ * may be negative, so care must be taken when shifting. For example,
+ * with a red mask of 0xFF0000, the red shift would be -16. With a red
+ * mask of 0x1F, the red shift would be 3.
+ * </p>
+ * </dd>
+ * </dl>
+ *
+ * @see Image
+ * @see RGB
+ */
+ 
+public final class PaletteData {
+	
+	/**
+	 * true if the receiver is a direct palette, 
+	 * and false otherwise
+	 */
+	public boolean isDirect;
+	
+	/**
+	 * the RGB values for an indexed palette, where the
+	 * indices of the array correspond to pixel values
+	 */
+	public RGB[] colors;
+	
+	/**
+	 * the red mask for a direct palette
+	 */
+	public int redMask;
+	
+	/**
+	 * the green mask for a direct palette
+	 */
+	public int greenMask;
+	
+	/**
+	 * the blue mask for a direct palette
+	 */
+	public int blueMask;
+	
+	/**
+	 * the red shift for a direct palette
+	 */
+	public int redShift;
+	
+	/**
+	 * the green shift for a direct palette
+	 */
+	public int greenShift;
+	
+	/**
+	 * the blue shift for a direct palette
+	 */
+	public int blueShift;
+
+/**
+ * Constructs a new indexed palette given an array of RGB values.
+ *
+ * @param colors the array of <code>RGB</code>s for the palette
+ *
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if the argument is null</li>
+ * </ul>
+ */
+public PaletteData(RGB[] colors) {
+	if (colors == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	this.colors = colors;
+	this.isDirect = false;
+}
+
+/**
+ * Constructs a new direct palette given the red, green and blue masks.
+ *
+ * @param redMask the red mask
+ * @param greenMask the green mask
+ * @param blueMask the blue mask
+ */
+public PaletteData(int redMask, int greenMask, int blueMask) {
+	this.redMask = redMask;
+	this.greenMask = greenMask;
+	this.blueMask = blueMask;
+	this.isDirect = true;
+	this.redShift = shiftForMask(redMask);
+	this.greenShift = shiftForMask(greenMask);
+	this.blueShift = shiftForMask(blueMask);
+}
+
+/**
+ * Returns the pixel value corresponding to the given <code>RBG</code>.
+ *
+ * @return the pixel value for the given RGB
+ * 
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if the argument is null</li>
+ *    <li>ERROR_INVALID_ARGUMENT - if the RGB is not found in the palette</li>
+ * </ul>
+ */
+public int getPixel(RGB rgb) {
+	if (rgb == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	if (isDirect) {
+		int pixel = 0;
+		pixel |= (redShift < 0 ? rgb.red << -redShift : rgb.red >>> redShift) & redMask;
+		pixel |= (greenShift < 0 ? rgb.green << -greenShift : rgb.green >>> greenShift) & greenMask;
+		pixel |= (blueShift < 0 ? rgb.blue << -blueShift : rgb.blue >>> blueShift) & blueMask;
+		return pixel;
+	} else {
+		for (int i = 0; i < colors.length; i++) {
+			if (colors[i].equals(rgb)) return i;
+		}
+		/* The RGB did not exist in the palette */
+		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+		return 0;
+	}
+}
+
+/**
+ * Returns an <code>RGB</code> corresponding to the given pixel value.
+ *
+ * @return the RGB value for the given pixel
+ *
+ * @exception IllegalArgumentException <ul>
+ *    <li>ERROR_NULL_ARGUMENT - if the argument is null</li>
+ *    <li>ERROR_INVALID_ARGUMENT - if the pixel does not exist in the palette</li>
+ * </ul>
+ */
+public RGB getRGB(int pixel) {
+	if (isDirect) {
+		int r = pixel & redMask;
+		r = (redShift < 0) ? r >>> -redShift : r << redShift;
+		int g = pixel & greenMask;
+		g = (greenShift < 0) ? g >>> -greenShift : g << greenShift;
+		int b = pixel & blueMask;
+		b = (blueShift < 0) ? b >>> -blueShift : b << blueShift;
+		return new RGB(r, g, b);
+	} else {
+		if (pixel < 0 || pixel >= colors.length) {
+			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+		}
+		return colors[pixel];
+	}
+}
+
+/**
+ * Returns all the RGB values in the receiver if it is an
+ * indexed palette, or null if it is a direct palette.
+ *
+ * @return the <code>RGB</code>s for the receiver or null
+ */
+public RGB[] getRGBs() {
+	return colors;
+}
+
+/**
+ * Computes the shift value for a given mask.
+ *
+ * @param mask the mask to compute the shift for
+ * @return the shift amount
+ *
+ * @see PaletteData
+ */
+int shiftForMask(int mask) {
+	for (int i = 31; i >= 0; i--) { 
+		if (((mask >> i) & 0x1) != 0) return 7 - i;
+	}
+	return 32;
+}
+
+}