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/*******************************************************************************
* 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.wpf.*;
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() {
OS.GCHandle_Free(handle);
handle = 0;
}
/**
* 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 OS.Color_B(handle) & 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 OS.Color_G(handle) & 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 OS.Color_R(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(OS.Color_R(handle) & 0xFF, OS.Color_G(handle) & 0xFF, OS.Color_B(handle) & 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 () {
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 = OS.Color_FromArgb((byte)0xFF, (byte)red, (byte)green, (byte)blue);
if (handle == 0) SWT.error(SWT.ERROR_NO_HANDLES);
}
/**
* 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 == 0;
}
/**
* 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 wpf_new(Device device, int handle) {
Color color = new Color(device);
color.handle = handle;
return color;
}
}
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