| /******************************************************************************* |
| * Copyright (c) 2000, 2012 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-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 |
| * @see <a href="http://www.eclipse.org/swt/snippets/#color">Color and RGB snippets</a> |
| * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: PaintExample</a> |
| * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a> |
| */ |
| public final class Color extends Resource { |
| |
| /** |
| * the handle to the OS color resource |
| * (Warning: This field is platform dependent) |
| * <p> |
| * <b>IMPORTANT:</b> This field is <em>not</em> part of the SWT |
| * public API. 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 accessed from application code. |
| * </p> |
| * |
| * @noreference This field is not intended to be referenced by clients. |
| */ |
| public int handle; |
| |
| /** |
| * Prevents uninitialized instances from being created outside the package. |
| */ |
| Color(Device device) { |
| super(device); |
| } |
| |
| /** |
| * 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) { |
| super(device); |
| init(red, green, blue); |
| init(); |
| } |
| |
| /** |
| * 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) { |
| super(device); |
| if (rgb == null) SWT.error(SWT.ERROR_NULL_ARGUMENT); |
| init(rgb.red, rgb.green, rgb.blue); |
| init(); |
| } |
| |
| void destroy() { |
| /* |
| * 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. |
| */ |
| long /*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; |
| } |
| |
| /** |
| * 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 that 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(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); |
| } |
| handle = (red & 0xFF) | ((green & 0xFF) << 8) | ((blue & 0xFF) << 16); |
| |
| /* If this is not a palette-based device, return */ |
| long /*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 (except {@link #dispose()}) 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 |
| * |
| * @noreference This method is not intended to be referenced by clients. |
| */ |
| public static Color win32_new(Device device, int handle) { |
| Color color = new Color(device); |
| color.handle = handle; |
| return color; |
| } |
| |
| } |