| /******************************************************************************* |
| * Copyright (c) 2000, 2008 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.motif.*; |
| 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 XColor handle; |
| |
| 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() { |
| int xDisplay = device.xDisplay; |
| int pixel = handle.pixel; |
| if (device.colorRefCount != null) { |
| /* If this was the last reference, remove the color from the list */ |
| if (--device.colorRefCount[pixel] == 0) { |
| device.xcolors[pixel] = null; |
| } |
| } |
| int colormap = OS.XDefaultColormap(xDisplay, OS.XDefaultScreen(xDisplay)); |
| OS.XFreeColors(xDisplay, colormap, new int[] { pixel }, 1, 0); |
| handle = 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; |
| XColor xColor = color.handle; |
| if (handle == xColor) return true; |
| return device == color.device && handle.red == xColor.red && |
| handle.green == xColor.green && handle.blue == xColor.blue; |
| } |
| /** |
| * 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.blue >> 8) & 0xFF; |
| } |
| /** |
| * 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.green >> 8) & 0xFF; |
| } |
| /** |
| * 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.red >> 8) & 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.red >> 8) & 0xFF, (handle.green >> 8) & 0xFF, (handle.blue >> 8) & 0xFF); |
| } |
| /** |
| * 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 () { |
| if (isDisposed()) return 0; |
| return handle.red ^ handle.green ^ handle.blue; |
| } |
| 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); |
| } |
| XColor xColor = new XColor(); |
| xColor.red = (short)((red & 0xFF) | ((red & 0xFF) << 8)); |
| xColor.green = (short)((green & 0xFF) | ((green & 0xFF) << 8)); |
| xColor.blue = (short)((blue & 0xFF) | ((blue & 0xFF) << 8)); |
| handle = xColor; |
| int xDisplay = device.xDisplay; |
| int screen = OS.XDefaultScreen(xDisplay); |
| int colormap = OS.XDefaultColormap(xDisplay, screen); |
| /* 1. Try to allocate the color */ |
| if (OS.XAllocColor(xDisplay, colormap, xColor) != 0) { |
| if (device.colorRefCount != null) { |
| /* Make a copy of the color to put in the colors array */ |
| XColor colorCopy = new XColor(); |
| colorCopy.red = xColor.red; |
| colorCopy.green = xColor.green; |
| colorCopy.blue = xColor.blue; |
| colorCopy.pixel = xColor.pixel; |
| device.xcolors[colorCopy.pixel] = colorCopy; |
| device.colorRefCount[xColor.pixel]++; |
| } |
| return; |
| } |
| /* |
| * 2. Allocation failed. Query the entire colormap and |
| * find the closest match which can be allocated. |
| * This should never occur on a truecolor display. |
| */ |
| Visual visual = new Visual(); |
| OS.memmove(visual, OS.XDefaultVisual(xDisplay, screen), Visual.sizeof); |
| int mapEntries = visual.map_entries; |
| XColor[] queried = new XColor[mapEntries]; |
| int[] distances = new int[mapEntries]; |
| /* |
| * Query all colors in the colormap and calculate the distance |
| * from each to the desired color. |
| */ |
| for (int i = 0; i < mapEntries; i++) { |
| XColor color = new XColor(); |
| color.pixel = i; |
| queried[i] = color; |
| OS.XQueryColor(xDisplay, colormap, color); |
| int r = red - ((color.red >> 8) & 0xFF); |
| int g = green - ((color.green >> 8) & 0xFF); |
| int b = blue - ((color.blue >> 8) & 0xFF); |
| distances[i] = r*r + g*g + b*b; |
| } |
| /* |
| * Try to allocate closest matching queried color. |
| * The allocation can fail if the closest matching |
| * color is allocated privately, so go through them |
| * in order of increasing distance. |
| */ |
| for (int i = 0; i < mapEntries; i++) { |
| int minDist = 0x30000; |
| int minIndex = 0; |
| for (int j = 0; j < mapEntries; j++) { |
| if (distances[j] < minDist) { |
| minDist = distances[j]; |
| minIndex = j; |
| } |
| } |
| XColor queriedColor = queried[minIndex]; |
| XColor osColor = new XColor(); |
| osColor.red = queriedColor.red; |
| osColor.green = queriedColor.green; |
| osColor.blue = queriedColor.blue; |
| if (OS.XAllocColor(xDisplay, colormap, osColor) != 0) { |
| /* Allocation succeeded. Copy the fields into the handle */ |
| xColor.red = osColor.red; |
| xColor.green = osColor.green; |
| xColor.blue = osColor.blue; |
| xColor.pixel = osColor.pixel; |
| if (device.colorRefCount != null) { |
| /* Put osColor in the colors array */ |
| device.xcolors[osColor.pixel] = osColor; |
| device.colorRefCount[osColor.pixel]++; |
| } |
| return; |
| } |
| /* The allocation failed; matching color is allocated privately */ |
| distances[minIndex] = 0x30000; |
| } |
| /* |
| * 3. Couldn't allocate any of the colors in the colormap. |
| * This means all colormap entries were allocated privately |
| * by other applications. Give up and allocate black. |
| */ |
| XColor osColor = new XColor(); |
| OS.XAllocColor(xDisplay, colormap, osColor); |
| /* Copy the fields into the handle */ |
| xColor.red = osColor.red; |
| xColor.green = osColor.green; |
| xColor.blue = osColor.blue; |
| xColor.pixel = osColor.pixel; |
| if (device.colorRefCount != null) { |
| /* Put osColor in the colors array */ |
| device.xcolors[osColor.pixel] = osColor; |
| device.colorRefCount[osColor.pixel]++; |
| } |
| } |
| /** |
| * 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 == null; |
| } |
| public static Color motif_new(Device device, XColor xColor) { |
| Color color = new Color(device); |
| color.handle = xColor; |
| return color; |
| } |
| /** |
| * 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*}"; |
| return "Color {" + getRed() + ", " + getGreen() + ", " + getBlue() + "}"; |
| } |
| } |