Package org.eclipse.swt.graphics

Class Color

java.lang.Object

org.eclipse.swt.graphics.Resource

org.eclipse.swt.graphics.Color

public class Color
extends Resource

Instances of this class manage resources that implement SWT's RGB color model.

Since:

1.0

See Also:

RGB, Device.getSystemColor(int)

Constructor Summary

Constructors

Constructor	Description
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.

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.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.
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.
java.lang.String	toString()	Returns a string containing a concise, human-readable description of the receiver.

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

dispose, getDevice, isDisposed

Methods inherited from class java.lang.Object

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

Constructor Detail

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

rgb - the RGB values of the desired color

Throws:

java.lang.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

Since:

1.3

See Also:

Resource.dispose()

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. 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

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:

java.lang.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:

3.1

See Also:

Resource.dispose()

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. On limited color devices, the color instance created by this call may not have the same RGBA values as the ones specified by the argument. The RGBA values on the returned instance will be the color values of the operating system color + alpha.

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

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:

java.lang.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:

3.1

See Also:

Resource.dispose()

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:

java.lang.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

Since:

1.3

See Also:

Resource.dispose()

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). 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

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

Throws:

java.lang.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:

3.1

See Also:

Resource.dispose()

Method Detail

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

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:

3.1

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:

3.1

equals

public boolean equals(java.lang.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 java.lang.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()

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 java.lang.Object

Returns:

the receiver's hash

See Also:

equals(java.lang.Object)

toString

public java.lang.String toString()

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

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the receiver