org.eclipse.swt.graphics
Class Color

java.lang.Object
  |
  +--org.eclipse.swt.graphics.Color

public final class Color

extends Object

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 RGB.

Application code must explicitly invoke the Color.dispose() method to release the operating system resources managed by each instance when those instances are no longer required.

See Also:

RGB, Device.getSystemColor(int)

Field Summary

int	handle the handle to the OS color resource (Warning: This field is platform dependent)

Constructor Summary

Color(Device device, int red, int green, int blue)
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).

Color(Device device, RGB rgb)
Constructs a new instance of this class given a device and an RGB describing the desired red, green and blue values.

Method Summary

void	dispose() Disposes of the operating system resources associated with the color.
boolean	equals(Object object) Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
int	getBlue() Returns the amount of blue in the color, from 0 to 255.
int	getGreen() Returns the amount of green in the color, from 0 to 255.
int	getRed() Returns the amount of red in the color, from 0 to 255.
RGB	getRGB() Returns an RGB representing the receiver.
int	hashCode() Returns an integer hash code for the receiver.
boolean	isDisposed() Returns true if the color has been disposed, and false otherwise.
String	toString() Returns a string containing a concise, human-readable description of the receiver.
static Color	win32_new(Device device, int handle) Invokes platform specific functionality to allocate a new color.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

handle

public int handle

the handle to the OS color resource (Warning: This field is platform dependent)

Constructor Detail

Color

public Color(Device device,
             int red,
             int green,
             int blue)

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.

You must dispose the color when it is no longer required.

Parameters:

device - the device on which to allocate the color

red - the amount of red in the color

green - the amount of green in the color

blue - the amount of blue in the color

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if device is null and there is no current device
• ERROR_INVALID_ARGUMENT - if the red, green or blue argument is not between 0 and 255

See Also:

dispose()

Color

public Color(Device device,
             RGB rgb)

Constructs a new instance of this class given a device and an RGB 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.

You must dispose the color when it is no longer required.

Parameters:

device - the device on which to allocate the color

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if device is null and there is no current device
• ERROR_NULL_ARGUMENT - if the rgb argument is null
• ERROR_INVALID_ARGUMENT - if the red, green or blue components of the argument are not between 0 and 255

See Also:

dispose()

Method Detail

dispose

public void dispose()

Disposes of the operating system resources associated with the color. Applications must dispose of all colors which they allocate.

equals

public boolean equals(Object object)

Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.

Overrides:

equals in class Object

Parameters:

object - the object to compare with this object

Returns:

true if the object is the same as this object and false otherwise

See Also:

hashCode()

getBlue

public int getBlue()

Returns the amount of blue in the color, from 0 to 255.

Returns:

the blue component of the color

Throws:

SWTException -

• ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

getGreen

public int getGreen()

Returns the amount of green in the color, from 0 to 255.

Returns:

the green component of the color

Throws:

SWTException -

• ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

getRed

public int getRed()

Returns the amount of red in the color, from 0 to 255.

Returns:

the red component of the color

Throws:

SWTException -

• ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

getRGB

public RGB getRGB()

Returns an RGB representing the receiver.

Throws:

SWTException -

• ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

hashCode

public int hashCode()

Returns an integer hash code for the receiver. Any two objects which return true when passed to equals must return the same value for this method.

Overrides:

hashCode in class Object

Returns:

the receiver's hash

See Also:

equals(java.lang.Object)

isDisposed

public boolean isDisposed()

Returns true if the color has been disposed, and false otherwise.

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.

Returns:

true when the color is disposed and false otherwise

toString

public String toString()

Returns a string containing a concise, human-readable description of the receiver.

Overrides:

toString in class Object

Returns:

a string representation of the receiver

win32_new

public static Color win32_new(Device device,
                              int handle)

Invokes platform specific functionality to allocate a new color.

IMPORTANT: This method is not part of the public API for Color. 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.

Parameters:

device - the device on which to allocate the color

handle - the handle for the color