Package org.eclipse.swt.graphics

Class Color

java.lang.Object

org.eclipse.swt.graphics.Resource

org.eclipse.swt.graphics.Color

public final class Color
extends Resource

Instances of this store color information. 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 or RGBA.

Colors do not need to be disposed, however to maintain compatibility with older code, disposing a Color is not an error. As Colors do not require disposal, the constructors which do not require a Device are recommended.

See Also:

RGB, RGBA, Device.getSystemColor(int), Color and RGB snippets, SWT Example: PaintExample, Sample code and further information

Field Summary

Fields

Modifier and Type	Field	Description
int	handle	the handle to the OS color resource (Warning: This field is platform dependent)

Constructor Summary

Constructors

Constructor	Description
Color(int red, int green, int blue)	Constructs a new instance of this class given 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(int red, int green, int blue, int alpha)	Constructs a new instance of this class given the desired red, green, blue & alpha values expressed as ints in the range 0 to 255 (where 0 is black and 255 is full brightness).
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, int red, int green, int blue, int alpha)	Constructs a new instance of this class given a device and the desired red, green, blue & alpha 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.
Color(Device device, RGBA rgba)	Constructs a new instance of this class given a device and an RGBA describing the desired red, green, blue & alpha values.
Color(Device device, RGB rgb, int alpha)	Constructs a new instance of this class given a device, an RGB describing the desired red, green and blue values, alpha specifying the level of transparency.
Color(RGB rgb)	Constructs a new instance of this class given an RGB describing the desired red, green and blue values.
Color(RGBA rgba)	Constructs a new instance of this class given an RGBA describing the desired red, green, blue & alpha values.
Color(RGB rgb, int alpha)	Constructs a new instance of this class given an RGB describing the desired red, green and blue values, alpha specifying the level of transparency.

Method Summary

Modifier and Type	Method	Description
void	dispose()	Colors do not need to be disposed, however to maintain compatibility with older code, disposing a Color is not an error.
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	getAlpha()	Returns the amount of alpha in the color, from 0 (transparent) to 255 (opaque).
int	getBlue()	Returns the amount of blue in the color, from 0 to 255.
Device	getDevice()	Returns the Device where this resource was created.
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.
RGBA	getRGBA()	Returns an RGBA 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.
static Color	win32_new(Device device, int handle, int alpha)	Invokes platform specific functionality to allocate a new color.

Methods inherited from class org.eclipse.swt.graphics.Resource

setNonDisposeHandler

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)

IMPORTANT: This field is not 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.

Restriction:

This field is not intended to be referenced by clients.

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).

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:

The equivalent constructor not requiring a Device

Color

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

Constructs a new instance of this class given 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).

Parameters:

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_INVALID_ARGUMENT - if the red, green or blue argument is not between 0 and 255

Since:

3.115

Color

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

Constructs a new instance of this class given a device and the desired red, green, blue & alpha values expressed as ints in the range 0 to 255 (where 0 is black and 255 is full brightness).

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

alpha - the amount of alpha in the color. Currently, SWT only honors extreme values for alpha i.e. 0 (transparent) or 255 (opaque).

Throws:

IllegalArgumentException -

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

Since:

3.104

See Also:

The equivalent constructor not requiring a Device

Color

public Color(int red,
             int green,
             int blue,
             int alpha)

Constructs a new instance of this class given the desired red, green, blue & alpha values expressed as ints in the range 0 to 255 (where 0 is black and 255 is full brightness).

Parameters:

red - the amount of red in the color

green - the amount of green in the color

blue - the amount of blue in the color

alpha - the amount of alpha in the color. Currently, SWT only honors extreme values for alpha i.e. 0 (transparent) or 255 (opaque).

Throws:

IllegalArgumentException -

• ERROR_INVALID_ARGUMENT - if the red, green, blue or alpha argument is not between 0 and 255

Since:

3.115

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.

Parameters:

device - the device on which to allocate the color

rgb - the RGB values of the desired 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:

The equivalent constructor not requiring a Device

Color

public Color(RGB rgb)

Constructs a new instance of this class given an RGB describing the desired red, green and blue values.

Parameters:

rgb - the RGB values of the desired color

Throws:

IllegalArgumentException -

• 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

Since:

3.115

Color

public Color(Device device,
             RGBA rgba)

Constructs a new instance of this class given a device and an RGBA describing the desired red, green, blue & alpha values.

Parameters:

device - the device on which to allocate the color

rgba - the RGBA values of the desired color. Currently, SWT only honors extreme values for alpha i.e. 0 (transparent) or 255 (opaque).

Throws:

IllegalArgumentException -

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

Since:

3.104

See Also:

The equivalent constructor not requiring a Device

Color

public Color(RGBA rgba)

Constructs a new instance of this class given an RGBA describing the desired red, green, blue & alpha values.

Parameters:

rgba - the RGBA values of the desired color. Currently, SWT only honors extreme values for alpha i.e. 0 (transparent) or 255 (opaque).

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the rgba argument is null
• ERROR_INVALID_ARGUMENT - if the red, green, blue or alpha components of the argument are not between 0 and 255

Since:

3.115

Color

public Color(Device device,
             RGB rgb,
             int alpha)

Constructs a new instance of this class given a device, an RGB describing the desired red, green and blue values, alpha specifying the level of transparency.

Parameters:

device - the device on which to allocate the color

rgb - the RGB values of the desired color

alpha - the alpha value of the desired color. Currently, SWT only honors extreme values for alpha i.e. 0 (transparent) or 255 (opaque).

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, blue or alpha components of the argument are not between 0 and 255

Since:

3.104

See Also:

The equivalent constructor not requiring a Device

Color

public Color(RGB rgb,
             int alpha)

Constructs a new instance of this class given an RGB describing the desired red, green and blue values, alpha specifying the level of transparency.

Parameters:

rgb - the RGB values of the desired color

alpha - the alpha value of the desired color. Currently, SWT only honors extreme values for alpha i.e. 0 (transparent) or 255 (opaque).

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the rgb argument is null
• ERROR_INVALID_ARGUMENT - if the red, green, blue or alpha components of the argument are not between 0 and 255

Since:

3.115

Method Detail

dispose

public void dispose()

Colors do not need to be disposed, however to maintain compatibility with older code, disposing a Color is not an error.

Overrides:

dispose in class Resource

getDevice

public Device getDevice()

Returns the Device where this resource was created. In cases where no Device was used at creation, returns the current or default Device.

As Color does not require a Device it is recommended to not use getDevice().

Overrides:

getDevice in class Resource

Returns:

Device the device of the receiver

Since:

3.2

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()

getAlpha

public int getAlpha()

Returns the amount of alpha in the color, from 0 (transparent) to 255 (opaque).

Returns:

the alpha component of the color

Throws:

SWTException -

• ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

Since:

3.104

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.

Returns:

the RGB for the color

Throws:

SWTException -

• ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

getRGBA

public RGBA getRGBA()

Returns an RGBA representing the receiver.

Returns:

the RGBA for the color

Throws:

SWTException -

• ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed

Since:

3.104

hashCode

public int hashCode()

Returns an integer hash code for the receiver. Any two objects that 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 (except dispose()) using the color.

Specified by:

isDisposed in class Resource

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

Returns:

a new color object containing the specified device and handle

Restriction:

This method is not intended to be referenced by clients.

win32_new

public static Color win32_new(Device device,
                              int handle,
                              int alpha)

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

alpha - the int for the alpha content in the color

Returns:

a new color object containing the specified device and handle

Restriction:

This method is not intended to be referenced by clients.