package org.eclipse.swt.graphics; | |
/* | |
* (c) Copyright IBM Corp. 2000, 2001. | |
* All Rights Reserved | |
*/ | |
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 | |
*/ | |
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_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_INVALID_ARGUMENT - if the red, green or blue components of the argument are not between 0 and 255</li> | |
* <li>ERROR_NULL_ARGUMENT - if the rgb argument is null</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 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. | |
* | |
* @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 */ | |
int offset = index * 4; | |
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*}"; | |
return "Color {" + getRed() + ", " + getGreen() + ", " + getBlue() + "}"; | |
} | |
/** | |
* 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 | |
* | |
* @private | |
*/ | |
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; | |
} | |
} |