bundles/org.eclipse.swt/Eclipse SWT/carbon/org/eclipse/swt/graphics/Image.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.graphics;

 
import org.eclipse.swt.internal.carbon.*;
import org.eclipse.swt.*;
import java.io.*;
 
/**
 * Instances of this class are graphics which have been prepared
 * for display on a specific device. That is, they are ready
 * to paint using methods such as <code>GC.drawImage()</code>
 * and display on widgets with, for example, <code>Button.setImage()</code>.
 * <p>
 * If loaded from a file format that supports it, an
 * <code>Image</code> may have transparency, meaning that certain
 * pixels are specified as being transparent when drawn. Examples
 * of file formats that support transparency are GIF and PNG.
 * </p><p>
 * There are two primary ways to use <code>Images</code>. 
 * The first is to load a graphic file from disk and create an
 * <code>Image</code> from it. This is done using an <code>Image</code>
 * constructor, for example:
 * <pre>
 *    Image i = new Image(device, "C:\\graphic.bmp");
 * </pre>
 * A graphic file may contain a color table specifying which
 * colors the image was intended to possess. In the above example,
 * these colors will be mapped to the closest available color in
 * SWT. It is possible to get more control over the mapping of
 * colors as the image is being created, using code of the form:
 * <pre>
 *    ImageData data = new ImageData("C:\\graphic.bmp"); 
 *    RGB[] rgbs = data.getRGBs(); 
 *    // At this point, rgbs contains specifications of all
 *    // the colors contained within this image. You may
 *    // allocate as many of these colors as you wish by
 *    // using the Color constructor Color(RGB), then
 *    // create the image:
 *    Image i = new Image(device, data);
 * </pre>
 * <p>
 * Applications which require even greater control over the image
 * loading process should use the support provided in class
 * <code>ImageLoader</code>.
 * </p><p>
 * Application code must explicitely invoke the <code>Image.dispose()</code> 
 * method to release the operating system resources managed by each instance
 * when those instances are no longer required.
 * </p>
 *
 * @see Color
 * @see ImageData
 * @see ImageLoader
 */
public final class Image implements Drawable{

	/**
	 * specifies whether the receiver is a bitmap or an icon
	 * (one of <code>SWT.BITMAP</code>, <code>SWT.ICON</code>)
	 */
	public int type;
	
	/**
	 * the handle to the OS image resource
	 * (Warning: This field is platform dependent)
	 */
	public int handle;

	/**
	 * The data to the OS image resource.
	 * Warning: This field is platform dependent.
	 */
	public int data;

	/**
	 * The device where this image was created.
	 */
	Device device;
	
	/**
	 * specifies the transparent pixel
	 * (Warning: This field is platform dependent)
	 */
	int transparentPixel = -1;
	
	/**
	 * The GC the image is currently selected in.
	 * Warning: This field is platform dependent.
	 */
	GC memGC;

	/**
	 * The alpha data of the image.
	 * Warning: This field is platform dependent.
	 */
	byte[] alphaData;
	
	/**
	 * The global alpha value to be used for every pixel.
	 * Warning: This field is platform dependent.
	 */
	int alpha = -1;
	
	/**
	 * Specifies the default scanline padding.
	 * Warning: This field is platform dependent.
	 */
	static final int DEFAULT_SCANLINE_PAD = 4;

Image() {
}

/**
 * Constructs an empty instance of this class with the
 * specified width and height. The result may be drawn upon
 * by creating a GC and using any of its drawing operations,
 * as shown in the following example:
 * <pre>
 *    Image i = new Image(device, width, height);
 *    GC gc = new GC(i);
 *    gc.drawRectangle(0, 0, 50, 50);
 *    gc.dispose();
 * </pre>
 * <p>
 * Note: Some platforms may have a limitation on the size
 * of image that can be created (size depends on width, height,
 * and depth). For example, Windows 95, 98, and ME do not allow
 * images larger than 16M.
 * </p>
 *
 * @param device the device on which to create the image
 * @param width the width of the new image
 * @param height the height of the new image
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_INVALID_ARGUMENT - if either the width or height is negative or zero</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for image creation</li>
 * </ul>
 */
public Image(Device display, int width, int height) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(device, width, height);
}

/**
 * Constructs a new instance of this class based on the
 * provided image, with an appearance that varies depending
 * on the value of the flag. The possible flag values are:
 * <dl>
 * <dt><b>IMAGE_COPY</b></dt>
 * <dd>the result is an identical copy of srcImage</dd>
 * <dt><b>IMAGE_DISABLE</b></dt>
 * <dd>the result is a copy of srcImage which has a <em>disabled</em> look</dd>
 * <dt><b>IMAGE_GRAY</b></dt>
 * <dd>the result is a copy of srcImage which has a <em>gray scale</em> look</dd>
 * </dl>
 *
 * @param device the device on which to create the image
 * @param srcImage the image to use as the source
 * @param flag the style, either <code>IMAGE_COPY</code>, <code>IMAGE_DISABLE</code> or <code>IMAGE_GRAY</code>
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if srcImage is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the flag is not one of <code>IMAGE_COPY</code>, <code>IMAGE_DISABLE</code> or <code>IMAGE_GRAY</code></li>
 *    <li>ERROR_INVALID_ARGUMENT - if the image has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_INVALID_IMAGE - if the image is not a bitmap or an icon, or
 *          is otherwise in an invalid state</li>
 *    <li>ERROR_UNSUPPORTED_DEPTH - if the depth of the Image is not supported</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for image creation</li>
 * </ul>
 */
public Image(Device device, Image srcImage, int flag) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (srcImage == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (srcImage.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	switch (flag) {
		case SWT.IMAGE_COPY:
		case SWT.IMAGE_DISABLE:
		case SWT.IMAGE_GRAY:
			break;
		default:
			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	this.device = device;
	this.type = srcImage.type;

	/* Get source image size */
 	int width = OS.CGImageGetWidth(srcImage.handle);
 	int height = OS.CGImageGetHeight(srcImage.handle);
 	int bpr = OS.CGImageGetBytesPerRow(srcImage.handle);
 	int bpc = OS.CGImageGetBitsPerComponent(srcImage.handle);
 	int bpp = OS.CGImageGetBitsPerPixel(srcImage.handle);
	int colorspace = OS.CGImageGetColorSpace(srcImage.handle);
	int alphaInfo = OS.kCGImageAlphaNoneSkipFirst;
 	
	/* Copy transparent pixel and alpha data when necessary */
	alphaInfo = OS.CGImageGetAlphaInfo(srcImage.handle);
	transparentPixel = srcImage.transparentPixel;
	alpha = srcImage.alpha;
	if (srcImage.alphaData != null) {
		alphaData = new byte[srcImage.alphaData.length];
		System.arraycopy(srcImage.alphaData, 0, alphaData, 0, alphaData.length);
	}

	/* Create the image */
	int dataSize = height * bpr;
	data = OS.NewPtr(dataSize);
	if (data == 0) SWT.error(SWT.ERROR_NO_HANDLES);
	int provider = OS.CGDataProviderCreateWithData(0, data, dataSize, 0);
	if (provider == 0) {
		OS.DisposePtr(data);
		SWT.error(SWT.ERROR_NO_HANDLES);
	}
	handle = OS.CGImageCreate(width, height, bpc, bpp, bpr, colorspace, alphaInfo, provider, null, false, 0);
	OS.CGDataProviderRelease(provider);
	if (handle == 0) {
		OS.DisposePtr(data);
		SWT.error(SWT.ERROR_NO_HANDLES);
	}
	
	OS.memcpy(data, srcImage.data, dataSize);
	if (flag == SWT.IMAGE_COPY) return;
	
	/* Apply transformation */
	switch (flag) {
		case SWT.IMAGE_DISABLE: {
			Color zeroColor = device.getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW);
			RGB zeroRGB = zeroColor.getRGB();
			byte zeroRed = (byte)zeroRGB.red;
			byte zeroGreen = (byte)zeroRGB.green;
			byte zeroBlue = (byte)zeroRGB.blue;
			Color oneColor = device.getSystemColor(SWT.COLOR_WIDGET_BACKGROUND);
			RGB oneRGB = oneColor.getRGB();
			byte oneRed = (byte)oneRGB.red;
			byte oneGreen = (byte)oneRGB.green;
			byte oneBlue = (byte)oneRGB.blue;
			byte[] line = new byte[bpr];
			for (int y=0; y<height; y++) {
				OS.memcpy(line, data + (y * bpr), bpr);
				int offset = 0;
				for (int x=0; x<width; x++) {
					int red = line[offset+1] & 0xFF;
					int green = line[offset+2] & 0xFF;
					int blue = line[offset+3] & 0xFF;
					int intensity = red * red + green * green + blue * blue;
					if (intensity < 98304) {
						line[offset+1] = zeroRed;
						line[offset+2] = zeroGreen;
						line[offset+3] = zeroBlue;
					} else {
						line[offset+1] = oneRed;
						line[offset+2] = oneGreen;
						line[offset+3] = oneBlue;
					}
					offset += 4;
				}
				OS.memcpy(data + (y * bpr), line, bpr);
			}
			break;
		}
		case SWT.IMAGE_GRAY: {			
			byte[] line = new byte[bpr];
			for (int y=0; y<height; y++) {
				OS.memcpy(line, data + (y * bpr), bpr);
				int offset = 0;
				for (int x=0; x<width; x++) {
					int red = line[offset+1] & 0xFF;
					int green = line[offset+2] & 0xFF;
					int blue = line[offset+3] & 0xFF;
					byte intensity = (byte)((red+red+green+green+green+green+green+blue) >> 3);
					line[offset+1] = line[offset+2] = line[offset+3] = intensity;
					offset += 4;
				}
				OS.memcpy(data + (y * bpr), line, bpr);
			}
			break;
		}
	}
}

/**
 * Constructs an empty instance of this class with the
 * width and height of the specified rectangle. The result
 * may be drawn upon by creating a GC and using any of its
 * drawing operations, as shown in the following example:
 * <pre>
 *    Image i = new Image(device, boundsRectangle);
 *    GC gc = new GC(i);
 *    gc.drawRectangle(0, 0, 50, 50);
 *    gc.dispose();
 * </pre>
 * <p>
 * Note: Some platforms may have a limitation on the size
 * of image that can be created (size depends on width, height,
 * and depth). For example, Windows 95, 98, and ME do not allow
 * images larger than 16M.
 * </p>
 *
 * @param device the device on which to create the image
 * @param bounds a rectangle specifying the image's width and height (must not be null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if the bounds rectangle is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if either the rectangle's width or height is negative</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for image creation</li>
 * </ul>
 */
public Image(Device display, Rectangle bounds) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (bounds == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(device, bounds.width, bounds.height);
}

/**
 * Constructs an instance of this class from the given
 * <code>ImageData</code>.
 *
 * @param device the device on which to create the image
 * @param data the image data to create the image from (must not be null)
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if the image data is null</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for image creation</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_UNSUPPORTED_DEPTH - if the depth of the ImageData is not supported</li>
 * </ul>
 */
public Image(Device device, ImageData data) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(device, data);
}

/**
 * Constructs an instance of this class, whose type is 
 * <code>SWT.ICON</code>, from the two given <code>ImageData</code>
 * objects. The two images must be the same size, and the mask image
 * must have a color depth of 1. Pixel transparency in either image
 * will be ignored. If either image is an icon to begin with, an
 * exception is thrown.
 * <p>
 * The mask image should contain white wherever the icon is to be visible,
 * and black wherever the icon is to be transparent. In addition,
 * the source image should contain black wherever the icon is to be
 * transparent.
 * </p>
 *
 * @param device the device on which to create the icon
 * @param source the color data for the icon
 * @param mask the mask data for the icon
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if either the source or mask is null </li>
 *    <li>ERROR_INVALID_ARGUMENT - if source and mask are different sizes or
 *          if the mask is not monochrome, or if either the source or mask
 *          is already an icon</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for image creation</li>
 * </ul>
 */
public Image(Device display, ImageData source, ImageData mask) {
	if (device == null) device = Device.getDevice();
	if (source == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (mask == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (source.width != mask.width || source.height != mask.height) {
		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	if (mask.depth != 1) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	ImageData image = new ImageData(source.width, source.height, source.depth, source.palette, source.scanlinePad, source.data);
	image.maskPad = mask.scanlinePad;
	image.maskData = mask.data;
	init(device, image);
}

/**
 * Constructs an instance of this class by loading its representation
 * from the specified input stream. Throws an error if an error
 * occurs while loading the image, or if the result is an image
 * of an unsupported type.
 * <p>
 * This constructor is provided for convenience when loading a single
 * image only. If the stream contains multiple images, only the first
 * one will be loaded. To load multiple images, use 
 * <code>ImageLoader.load()</code>.
 * </p><p>
 * This constructor may be used to load a resource as follows:
 * </p>
 * <pre>
 *     new Image(device, clazz.getResourceAsStream("file.gif"));
 * </pre>
 *
 * @param device the device on which to create the image
 * @param stream the input stream to load the image from
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if the stream is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_INVALID_IMAGE - if the image file contains invalid data </li>
 *    <li>ERROR_IO - if an IO error occurs while reading data</li>
 *    <li>ERROR_UNSUPPORTED_DEPTH - if the InputStream describes an image with an unsupported depth</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for image creation</li>
 * </ul>
 */
public Image(Device device, InputStream stream) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(device, new ImageData(stream));
}

/**
 * Constructs an instance of this class by loading its representation
 * from the file with the specified name. Throws an error if an error
 * occurs while loading the image, or if the result is an image
 * of an unsupported type.
 * <p>
 * This constructor is provided for convenience when loading
 * a single image only. If the specified file contains
 * multiple images, only the first one will be used.
 *
 * @param device the device on which to create the image
 * @param filename the name of the file to load the image from
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
 *    <li>ERROR_NULL_ARGUMENT - if the file name is null</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_INVALID_IMAGE - if the image file contains invalid data </li>
 *    <li>ERROR_IO - if an IO error occurs while reading data</li>
 *    <li>ERROR_UNSUPPORTED_DEPTH - if the image file has an unsupported depth</li>
 * </ul>
 * @exception SWTError <ul>
 *    <li>ERROR_NO_HANDLES if a handle could not be obtained for image creation</li>
 * </ul>
 */
public Image(Device display, String filename) {
	if (device == null) device = Device.getDevice();
	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	init(device, new ImageData(filename));
}

void createMask () {
	if (transparentPixel == -1) return;
	int height = OS.CGImageGetHeight(handle);
	int bpr = OS.CGImageGetBytesPerRow(handle);
	int dataSize = height * bpr;
	byte[] srcData = new byte[dataSize];
	OS.memcpy(srcData, data, dataSize);
	for (int i=0; i<dataSize; i+=4) {
		int pixel = ((srcData[i+1] & 0xFF) << 16) | ((srcData[i+2] & 0xFF) << 8) | (srcData[i+3] & 0xFF);
		srcData[i] = (byte)(pixel == transparentPixel ? 0 : 0xFF); 
	}
	OS.memcpy(data, srcData, dataSize);
}

/**
 * Disposes of the operating system resources associated with
 * the image. Applications must dispose of all images which
 * they allocate.
 */
public void dispose () {
	if (handle == 0) return;
	if (device.isDisposed()) return;
	if (memGC != null) memGC.dispose();
	OS.CGImageRelease(handle);
	OS.DisposePtr(data);
	device = null;
	data = handle = 0;
	memGC = null;
}

/**
 * Compares the argument to the receiver, and returns true
 * if they represent the <em>same</em> object using a class
 * specific comparison.
 *
 * @param object the object to compare with this object
 * @return <code>true</code> if the object is the same as this object and <code>false</code> otherwise
 *
 * @see #hashCode
 */
public boolean equals (Object object) {
	if (object == this) return true;
	if (!(object instanceof Image)) return false;
	Image image = (Image)object;
	return device == image.device && handle == image.handle &&
		transparentPixel == image.transparentPixel;
}

/**
 * Returns the color to which to map the transparent pixel, or null if
 * the receiver has no transparent pixel.
 * <p>
 * There are certain uses of Images that do not support transparency
 * (for example, setting an image into a button or label). In these cases,
 * it may be desired to simulate transparency by using the background
 * color of the widget to paint the transparent pixels of the image.
 * Use this method to check which color will be used in these cases
 * in place of transparency. This value may be set with setBackground().
 * <p>
 *
 * @return the background color of the image, or null if there is no transparency in the image
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public Color getBackground() {
	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (transparentPixel == -1) return null;
	//NOT DONE
	return null;
}

/**
 * Returns the bounds of the receiver. The rectangle will always
 * have x and y values of 0, and the width and height of the
 * image.
 *
 * @return a rectangle specifying the image's bounds
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_INVALID_IMAGE - if the image is not a bitmap or an icon</li>
 * </ul>
 */
public Rectangle getBounds() {
	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	return new Rectangle(0, 0, OS.CGImageGetWidth(handle), OS.CGImageGetHeight(handle));
}

/**
 * Returns an <code>ImageData</code> based on the receiver
 * Modifications made to this <code>ImageData</code> will not
 * affect the Image.
 *
 * @return an <code>ImageData</code> containing the image's data and attributes
 *
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 *    <li>ERROR_INVALID_IMAGE - if the image is not a bitmap or an icon</li>
 * </ul>
 *
 * @see ImageData
 */
public ImageData getImageData() {
	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);

	int width = OS.CGImageGetWidth(handle);
	int height = OS.CGImageGetHeight(handle);
	int bpr = OS.CGImageGetBytesPerRow(handle);
	int bpp = OS.CGImageGetBitsPerPixel(handle);	
	int dataSize = height * bpr;
	byte[] srcData = new byte[dataSize];
	OS.memcpy(srcData, data, dataSize);
	
	PaletteData palette = new PaletteData(0xFF0000, 0xFF00, 0xFF);
	ImageData data = new ImageData(width, height, bpp, palette);
	data.data = srcData;
	data.bytesPerLine = bpr;

	data.transparentPixel = transparentPixel;
	if (transparentPixel == -1 && type == SWT.ICON) {
		/* Get the icon mask data */
		int maskPad = 2;
		int maskBpl = (((width + 7) / 8) + (maskPad - 1)) / maskPad * maskPad;
		byte[] maskData = new byte[height * maskBpl];
		int offset = 0, maskOffset = 0;
		for (int y = 0; y<height; y++) {
			for (int x = 0; x<width; x++) {
				if (srcData[offset] != 0) {
					maskData[maskOffset + (x >> 3)] |= (1 << (7 - (x & 0x7)));
				} else {
					maskData[maskOffset + (x >> 3)] &= ~(1 << (7 - (x & 0x7)));
				}
				offset += 4;
			}
			maskOffset += maskBpl;
		}
		data.maskData = maskData;
		data.maskPad = maskPad;
	}
	data.alpha = alpha;
	if (alpha == -1 && alphaData != null) {
		data.alphaData = new byte[alphaData.length];
		System.arraycopy(alphaData, 0, data.alphaData, 0, alphaData.length);
	}
	return data;
}

/**	 
 * Invokes platform specific functionality to allocate a new image.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Image</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @param device the device on which to allocate the color
 * @param type the type of the image (<code>SWT.BITMAP</code> or <code>SWT.ICON</code>)
 * @param handle the OS handle for the image
 * @param data the OS data for the image
 *
 * @private
 */
public static Image carbon_new(Device device, int type, int handle, int data) {
	if (device == null) device = Device.getDevice();
	Image image = new Image();
	image.type = type;
	image.handle = handle;
	image.data = data;
	image.device = device;
	return image;
}

/**
 * Returns an integer hash code for the receiver. Any two 
 * objects which return <code>true</code> when passed to 
 * <code>equals</code> must return the same value for this
 * method.
 *
 * @return the receiver's hash
 *
 * @see #equals
 */
public int hashCode () {
	return handle;
}

void init(Device device, int width, int height) {
	if (width <= 0 || height <= 0) {
		SWT.error (SWT.ERROR_INVALID_ARGUMENT);
	}
	this.device = device;
	this.type = SWT.BITMAP;

	/* Create the image */
	int bpr = width * 4;
	int dataSize = height * bpr;
	data = OS.NewPtr(dataSize);
	if (data == 0) SWT.error(SWT.ERROR_NO_HANDLES);
	int provider = OS.CGDataProviderCreateWithData(0, data, dataSize, 0);
	if (provider == 0) {
		OS.DisposePtr(data);
		SWT.error(SWT.ERROR_NO_HANDLES);
	}
	int colorspace = device.colorspace;
	handle = OS.CGImageCreate(width, height, 8, 32, bpr, colorspace, OS.kCGImageAlphaNoneSkipFirst, provider, null, false, 0);
	OS.CGDataProviderRelease(provider);
	if (handle == 0) {
		OS.DisposePtr(data);
		SWT.error(SWT.ERROR_NO_HANDLES);
	}
		
	/* Fill the image with white */
	int bpc = OS.CGImageGetBitsPerComponent(handle);
	int context = OS.CGBitmapContextCreate(this.data, width, height, bpc, bpr, colorspace, OS.kCGImageAlphaNoneSkipFirst);
	CGRect rect = new CGRect();
	rect.width = width; rect.height = height;
	OS.CGContextSetRGBFillColor(context, 1, 1, 1, 1);
	OS.CGContextFillRect(context, rect);
	OS.CGContextRelease(context);
}

void init(Device device, ImageData image) {
	if (image == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	this.device = device;
	int width = image.width;
	int height = image.height;
	PaletteData palette = image.palette;
	if (!(((image.depth == 1 || image.depth == 2 || image.depth == 4 || image.depth == 8) && !palette.isDirect) ||
			((image.depth == 8) || (image.depth == 16 || image.depth == 24 || image.depth == 32) && palette.isDirect)))
				SWT.error(SWT.ERROR_UNSUPPORTED_DEPTH);

	
	/* Create the image */
	int dataSize = width * height * 4;
	data = OS.NewPtr(dataSize);
	if (data == 0) SWT.error(SWT.ERROR_NO_HANDLES);
	int provider = OS.CGDataProviderCreateWithData(0, data, dataSize, 0);
	if (provider == 0) {
		OS.DisposePtr(data);
		SWT.error(SWT.ERROR_NO_HANDLES);
	}
	int colorspace = device.colorspace;
	int transparency = image.getTransparencyType(); 
	int alphaInfo = transparency == SWT.TRANSPARENCY_NONE ? OS.kCGImageAlphaNoneSkipFirst : OS.kCGImageAlphaFirst;
	handle = OS.CGImageCreate(width, height, 8, 32, width * 4, colorspace, alphaInfo, provider, null, false, 0);
	OS.CGDataProviderRelease(provider);
	if (handle == 0) {
		OS.DisposePtr(data);
		SWT.error(SWT.ERROR_NO_HANDLES);
	}
	
	/* Initialize data */
	int bpr = width * 4;
	byte[] buffer = new byte[dataSize];
	if (palette.isDirect) {
		ImageData.blit(ImageData.BLIT_SRC,
			image.data, image.depth, image.bytesPerLine, image.getByteOrder(), 0, 0, width, height, palette.redMask, palette.greenMask, palette.blueMask,
			ImageData.ALPHA_OPAQUE, null, 0, 0, 0, 
			buffer, 32, bpr, ImageData.MSB_FIRST, 0, 0, width, height, 0xFF0000, 0xFF00, 0xFF,
			false, false);
	} else {
		RGB[] rgbs = palette.getRGBs();
		int length = rgbs.length;
		byte[] srcReds = new byte[length];
		byte[] srcGreens = new byte[length];
		byte[] srcBlues = new byte[length];
		for (int i = 0; i < rgbs.length; i++) {
			RGB rgb = rgbs[i];
			if (rgb == null) continue;
			srcReds[i] = (byte)rgb.red;
			srcGreens[i] = (byte)rgb.green;
			srcBlues[i] = (byte)rgb.blue;
		}
		ImageData.blit(ImageData.BLIT_SRC,
			image.data, image.depth, image.bytesPerLine, image.getByteOrder(), 0, 0, width, height, srcReds, srcGreens, srcBlues,
			ImageData.ALPHA_OPAQUE, null, 0, 0, 0,
			buffer, 32, bpr, ImageData.MSB_FIRST, 0, 0, width, height, 0xFF0000, 0xFF00, 0xFF,
			false, false);
	}
	
	/* Initialize transparency */
	if (transparency == SWT.TRANSPARENCY_MASK || image.transparentPixel != -1) {
		this.type = image.transparentPixel != -1 ? SWT.BITMAP : SWT.ICON;
		if (image.transparentPixel != -1) {
			int transRed = 0, transGreen = 0, transBlue = 0;
			if (palette.isDirect) {
				RGB rgb = palette.getRGB(image.transparentPixel);
				transRed = rgb.red;
				transGreen = rgb.green;
				transBlue = rgb.blue;
			} else {
				RGB[] rgbs = palette.getRGBs();
				if (image.transparentPixel < rgbs.length) {
					RGB rgb = rgbs[image.transparentPixel];
					transRed = rgb.red;
					transGreen = rgb.green;
					transBlue = rgb.blue;				
				}
			}
			transparentPixel = transRed << 16 | transGreen << 8 | transBlue;
		}
		ImageData maskImage = image.getTransparencyMask();
		byte[] maskData = maskImage.data;
		int maskBpl = maskImage.bytesPerLine;
		int offset = 0, maskOffset = 0;
		for (int y = 0; y<height; y++) {
			for (int x = 0; x<width; x++) {
				buffer[offset] = ((maskData[maskOffset + (x >> 3)]) & (1 << (7 - (x & 0x7)))) != 0 ? (byte)0xff : 0;
				offset += 4;
			}
			maskOffset += maskBpl;
		}
	} else {
		this.type = SWT.BITMAP;
		if (image.alpha != -1) {
			this.alpha = image.alpha;
			byte a = (byte)this.alpha;
			for (int dataIndex=0; dataIndex<buffer.length; dataIndex+=4) {
				buffer[dataIndex] = a;				
			}
		} else if (image.alphaData != null) {
			this.alphaData = new byte[image.alphaData.length];
			System.arraycopy(image.alphaData, 0, this.alphaData, 0, alphaData.length);
			int offset = 0, alphaOffset = 0;
			for (int y = 0; y<height; y++) {
				for (int x = 0; x<width; x++) {
					buffer[offset] = alphaData[alphaOffset];
					offset += 4;
					alphaOffset += 1;
				}
			}
		}
	}
	
	OS.memcpy(data, buffer, dataSize);
}

/**	 
 * Invokes platform specific functionality to allocate a new GC handle.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Image</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @param data the platform specific GC data 
 * @return the platform specific GC handle
 */
public int internal_new_GC (GCData data) {
	if (handle == 0) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (type != SWT.BITMAP || memGC != null) {
		SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	}
	int width = OS.CGImageGetWidth(handle);
	int height = OS.CGImageGetHeight(handle);
	int bpc = OS.CGImageGetBitsPerComponent(handle);
	int bpr = OS.CGImageGetBytesPerRow(handle);
	int colorspace = OS.CGImageGetColorSpace(handle);
	int context = OS.CGBitmapContextCreate(this.data, width, height, bpc, bpr, colorspace, OS.kCGImageAlphaNoneSkipFirst);
	if (context == 0) SWT.error(SWT.ERROR_NO_HANDLES);
	OS.CGContextScaleCTM(context, 1, -1);
	OS.CGContextTranslateCTM(context, 0, -height);
	OS.CGContextSetShouldSmoothFonts(context, false);
	if (data != null) {
		int mask = SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
		if ((data.style & mask) == 0) {
			data.style |= SWT.LEFT_TO_RIGHT;
		}
		data.device = device;
		data.background = device.COLOR_WHITE.handle;
		data.foreground = device.COLOR_BLACK.handle;
		data.font = device.systemFont;
		data.image = this;
	}
	return context;
}

/**	 
 * Invokes platform specific functionality to dispose a GC handle.
 * <p>
 * <b>IMPORTANT:</b> This method is <em>not</em> part of the public
 * API for <code>Image</code>. It is marked public only so that it
 * can be shared within the packages provided by SWT. It is not
 * available on all platforms, and should never be called from
 * application code.
 * </p>
 *
 * @param hDC the platform specific GC handle
 * @param data the platform specific GC data 
 */
public void internal_dispose_GC (int context, GCData data) {
	OS.CGContextRelease(context);
}

/**
 * Returns <code>true</code> if the image has been disposed,
 * and <code>false</code> otherwise.
 * <p>
 * This method gets the dispose state for the image.
 * When an image has been disposed, it is an error to
 * invoke any other method using the image.
 *
 * @return <code>true</code> when the image is disposed and <code>false</code> otherwise
 */
public boolean isDisposed() {
	return handle == 0;
}

/**
 * Sets the color to which to map the transparent pixel.
 * <p>
 * There are certain uses of <code>Images</code> that do not support
 * transparency (for example, setting an image into a button or label).
 * In these cases, it may be desired to simulate transparency by using
 * the background color of the widget to paint the transparent pixels
 * of the image. This method specifies the color that will be used in
 * these cases. For example:
 * <pre>
 *    Button b = new Button();
 *    image.setBackground(b.getBackground());
 *    b.setImage(image);
 * </pre>
 * </p><p>
 * The image may be modified by this operation (in effect, the
 * transparent regions may be filled with the supplied color).  Hence
 * this operation is not reversible and it is not legal to call
 * this function twice or with a null argument.
 * </p><p>
 * This method has no effect if the receiver does not have a transparent
 * pixel value.
 * </p>
 *
 * @param color the color to use when a transparent pixel is specified
 *
 * @exception IllegalArgumentException <ul>
 *    <li>ERROR_NULL_ARGUMENT - if the color is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if the color has been disposed</li>
 * </ul>
 * @exception SWTException <ul>
 *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li>
 * </ul>
 */
public void setBackground(Color color) {
	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);
	if (color == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
	if (color.isDisposed()) SWT.error(SWT.ERROR_INVALID_ARGUMENT);
	if (transparentPixel == -1) return;
	//NOT DONE
}

/**
 * Returns a string containing a concise, human-readable
 * description of the receiver.
 *
 * @return a string representation of the receiver
 */
public String toString () {
	if (isDisposed()) return "Image {*DISPOSED*}";
	return "Image {" + handle + "}";
}

}