/******************************************************************************* * Copyright (c) 2000, 2004 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.win32.*;import org.eclipse.swt.*;/** * Instances of this class manage the operating system resources that * implement SWT's RGB color model. To create a color you can either * specify the individual color components as integers in the range  * 0 to 255 or provide an instance of an <code>RGB</code>.  * <p> * Application code must explicitly invoke the <code>Color.dispose()</code>  * method to release the operating system resources managed by each instance * when those instances are no longer required. * </p> * * @see RGB * @see Device#getSystemColor */public final class Color {		/**	 * the handle to the OS color resource 	 * (Warning: This field is platform dependent)	 */	public int handle;		/**	 * the device where this color was created	 */	Device device;/** * Prevents uninitialized instances from being created outside the package. */Color() {	}/**	  * Constructs a new instance of this class given a device and the * desired red, green and blue values expressed as ints in the range * 0 to 255 (where 0 is black and 255 is full brightness). On limited * color devices, the color instance created by this call may not have * the same RGB values as the ones specified by the arguments. The * RGB values on the returned instance will be the color values of  * the operating system color. * <p> * You must dispose the color when it is no longer required.  * </p> * * @param device the device on which to allocate the color * @param red the amount of red in the color * @param green the amount of green in the color * @param blue the amount of blue in the color * * @exception IllegalArgumentException <ul> *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li> *    <li>ERROR_INVALID_ARGUMENT - if the red, green or blue argument is not between 0 and 255</li> * </ul> * * @see #dispose */public Color (Device device, int red, int green, int blue) {	if (device == null) device = Device.getDevice();	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);	init(device, red, green, blue);	if (device.tracking) device.new_Object(this);}/**	  * Constructs a new instance of this class given a device and an * <code>RGB</code> describing the desired red, green and blue values. * On limited color devices, the color instance created by this call * may not have the same RGB values as the ones specified by the * argument. The RGB values on the returned instance will be the color * values of the operating system color. * <p> * You must dispose the color when it is no longer required.  * </p> * * @param device the device on which to allocate the color * @param rgb the RGB values of the desired color * * @exception IllegalArgumentException <ul> *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li> *    <li>ERROR_NULL_ARGUMENT - if the rgb argument is null</li> *    <li>ERROR_INVALID_ARGUMENT - if the red, green or blue components of the argument are not between 0 and 255</li> * </ul> * * @see #dispose */public Color (Device device, RGB rgb) {	if (device == null) device = Device.getDevice();	if (device == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);	if (rgb == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);	init(device, rgb.red, rgb.green, rgb.blue);	if (device.tracking) device.new_Object(this);}/** * Disposes of the operating system resources associated with * the color. Applications must dispose of all colors which * they allocate. */public void dispose() {	if (handle == -1) return;	if (device.isDisposed()) return;	/*	 * If this is a palette-based device,	 * Decrease the reference count for this color.	 * If the reference count reaches 0, the slot may	 * be reused when another color is allocated.	 */	int hPal = device.hPalette;	if (hPal != 0) {		int index = OS.GetNearestPaletteIndex(hPal, handle);		int[] colorRefCount = device.colorRefCount;		if (colorRefCount[index] > 0) {			colorRefCount[index]--;		}	}	handle = -1;	if (device.tracking) device.dispose_Object(this);	device = 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 Color)) return false;	Color color = (Color) object;	return device == color.device && (handle & 0xFFFFFF) == (color.handle & 0xFFFFFF);}/** * Returns the amount of blue in the color, from 0 to 255. * * @return the blue component of the color * * @exception SWTException <ul> *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */public int getBlue () {	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);	return (handle & 0xFF0000) >> 16;}/** * Returns the amount of green in the color, from 0 to 255. * * @return the green component of the color * * @exception SWTException <ul> *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */public int getGreen () {	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);	return (handle & 0xFF00) >> 8 ;}/** * Returns the amount of red in the color, from 0 to 255. * * @return the red component of the color * * @exception SWTException <ul> *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */public int getRed () {	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);	return handle & 0xFF;}/** * Returns an <code>RGB</code> representing the receiver. * * @return the RGB for the color * * @exception SWTException <ul> *    <li>ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed</li> * </ul> */public RGB getRGB () {	if (isDisposed()) SWT.error(SWT.ERROR_GRAPHIC_DISPOSED);	return new RGB(handle & 0xFF, (handle & 0xFF00) >> 8, (handle & 0xFF0000) >> 16);}/** * 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;}/** * Allocates the operating system resources associated  * with the receiver. * * @param device the device on which to allocate the color * @param red the amount of red in the color * @param green the amount of green in the color * @param blue the amount of blue in the color * * @exception IllegalArgumentException <ul> *    <li>ERROR_INVALID_ARGUMENT - if the red, green or blue argument is not between 0 and 255</li> * </ul> * * @see #dispose */void init(Device device, int red, int green, int blue) {	if (red > 255 || red < 0 || green > 255 || green < 0 || blue > 255 || blue < 0) {		SWT.error(SWT.ERROR_INVALID_ARGUMENT);	}	this.device = device;	handle = 0x02000000 | (red & 0xFF) | ((green & 0xFF) << 8) | ((blue & 0xFF) << 16);		/* If this is not a palette-based device, return */	int hPal = device.hPalette;	if (hPal == 0) return;		int[] colorRefCount = device.colorRefCount;	/* Add this color to the default palette now */	/* First find out if the color already exists */	int index = OS.GetNearestPaletteIndex(hPal, handle);	/* See if the nearest color actually is the color */	byte[] entry = new byte[4];	OS.GetPaletteEntries(hPal, index, 1, entry);	if ((entry[0] == (byte)red) && (entry[1] == (byte)green) &&		(entry[2] == (byte)blue)) {			/* Found the color. Increment the ref count and return */			colorRefCount[index]++;			return;	}	/* Didn't find the color, allocate it now. Find the first free entry */	int i = 0;	while (i < colorRefCount.length) {		if (colorRefCount[i] == 0) {			index = i;			break;		}		i++;	}	if (i == colorRefCount.length) {		/* No free entries, use the closest one */		/* Remake the handle from the actual rgbs */		handle = (entry[0] & 0xFF) | ((entry[1] & 0xFF) << 8) |				 ((entry[2] & 0xFF) << 16);	} else {		/* Found a free entry */		entry = new byte[] { (byte)(red & 0xFF), (byte)(green & 0xFF), (byte)(blue & 0xFF), 0 };		OS.SetPaletteEntries(hPal, index, 1, entry);	}	colorRefCount[index]++;}/** * Returns <code>true</code> if the color has been disposed, * and <code>false</code> otherwise. * <p> * This method gets the dispose state for the color. * When a color has been disposed, it is an error to * invoke any other method using the color. * * @return <code>true</code> when the color is disposed and <code>false</code> otherwise */public boolean isDisposed() {	return handle == -1;}/** * 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 "Color {*DISPOSED*}"; //$NON-NLS-1$	return "Color {" + getRed() + ", " + getGreen() + ", " + getBlue() + "}"; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$}/**	  * Invokes platform specific functionality to allocate a new color. * <p> * <b>IMPORTANT:</b> This method is <em>not</em> part of the public * API for <code>Color</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 handle the handle for the color * @return a new color object containing the specified device and handle */public static Color win32_new(Device device, int handle) {	if (device == null) device = Device.getDevice();	Color color = new Color();	color.handle = handle;	color.device = device;	return color;}}