GI.Gdk.Structs.RGBA

A RGBA is used to represent a (possibly translucent) color, in a way that is compatible with cairo’s notion of color.

Exported types

newtype RGBA

Memory-managed wrapper type.

Constructors

RGBA (ManagedPtr RGBA)

Instances

Eq RGBA

Defined in GI.Gdk.Structs.RGBA

Methods

(==) :: RGBA -> RGBA -> Bool

(/=) :: RGBA -> RGBA -> Bool

IsGValue RGBA

Convert RGBA to and from GValue with toGValue and fromGValue.

Defined in GI.Gdk.Structs.RGBA

Methods

toGValue :: RGBA -> IO GValue

fromGValue :: GValue -> IO RGBA

ManagedPtrNewtype RGBA

Defined in GI.Gdk.Structs.RGBA

Methods

toManagedPtr :: RGBA -> ManagedPtr RGBA

TypedObject RGBA

Defined in GI.Gdk.Structs.RGBA

Methods

glibType :: IO GType

GBoxed RGBA

Defined in GI.Gdk.Structs.RGBA

HasParentTypes RGBA

Defined in GI.Gdk.Structs.RGBA

tag ~ 'AttrSet => Constructible RGBA tag

Defined in GI.Gdk.Structs.RGBA

Methods

new :: MonadIO m => (ManagedPtr RGBA -> RGBA) -> [AttrOp RGBA tag] -> m RGBA

type ParentTypes RGBA

Defined in GI.Gdk.Structs.RGBA

type ParentTypes RGBA = '[] :: [Type]

newZeroRGBA :: MonadIO m => m RGBA

Construct a RGBA struct initialized to zero.

Methods

Overloaded methods

copy

rGBACopy

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

rgba: a RGBA

-> m RGBA

Returns: A newly allocated RGBA, with the same contents as rgba

Makes a copy of a RGBA.

The result must be freed through rGBAFree.

equal

rGBAEqual

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

p1: a RGBA pointer

-> RGBA

p2: another RGBA pointer

-> m Bool

Returns: True if the two colors compare equal

Compares two RGBA colors.

free

rGBAFree

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

rgba: a RGBA

-> m ()

Frees a RGBA created with rGBACopy

hash

rGBAHash

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

p: a RGBA pointer

-> m Word32

Returns: The hash value for p

A hash function suitable for using for a hash table that stores GdkRGBAs.

isClear

rGBAIsClear

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

rgba: a RGBA

-> m Bool

Returns: True if the rgba is clear

Checks if an rgba value is transparent. That is, drawing with the value would not produce any change.

isOpaque

rGBAIsOpaque

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

rgba: a RGBA

-> m Bool

Returns: True if the rgba is opaque

Checks if an rgba value is opaque. That is, drawing with the value will not retain any results from previous contents.

parse

rGBAParse

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

rgba: the RGBA to fill in

-> Text

spec: the string specifying the color

-> m Bool

Returns: True if the parsing succeeded

Parses a textual representation of a color, filling in the red, green, blue and alpha fields of the rgba RGBA.

The string can be either one of:

• A standard name (Taken from the X11 rgb.txt file).
• A hexadecimal value in the form “rrggbb”, “rrrrggggbbbb”
• A RGB color in the form “rgb(r,g,b)” (In this case the color will have full opacity)
• A RGBA color in the form “rgba(r,g,b,a)”

Where “r”, “g”, “b” and “a” are respectively the red, green, blue and alpha color values. In the last two cases, “r”, “g”, and “b” are either integers in the range 0 to 255 or percentage values in the range 0% to 100%, and a is a floating point value in the range 0 to 1.

toString

rGBAToString

Arguments

:: (HasCallStack, MonadIO m)

=> RGBA

rgba: a RGBA

-> m Text

Returns: A newly allocated text string

Returns a textual specification of rgba in the form rgb(r,g,b) or rgba(r g,b,a), where “r”, “g”, “b” and “a” represent the red, green, blue and alpha values respectively. “r”, “g”, and “b” are represented as integers in the range 0 to 255, and “a” is represented as a floating point value in the range 0 to 1.

These string forms are string forms that are supported by the CSS3 colors module, and can be parsed by rGBAParse.

Note that this string representation may lose some precision, since “r”, “g” and “b” are represented as 8-bit integers. If this is a concern, you should use a different representation.

Properties

alpha

The opacity of the color from 0.0 for completely translucent to 1.0 for opaque

getRGBAAlpha :: MonadIO m => RGBA -> m Float

Get the value of the “alpha” field. When overloading is enabled, this is equivalent to

get rGBA #alpha

setRGBAAlpha :: MonadIO m => RGBA -> Float -> m ()

Set the value of the “alpha” field. When overloading is enabled, this is equivalent to

set rGBA [ #alpha := value ]

blue

The intensity of the blue channel from 0.0 to 1.0 inclusive

getRGBABlue :: MonadIO m => RGBA -> m Float

Get the value of the “blue” field. When overloading is enabled, this is equivalent to

get rGBA #blue

setRGBABlue :: MonadIO m => RGBA -> Float -> m ()

Set the value of the “blue” field. When overloading is enabled, this is equivalent to

set rGBA [ #blue := value ]

green

The intensity of the green channel from 0.0 to 1.0 inclusive

getRGBAGreen :: MonadIO m => RGBA -> m Float

Get the value of the “green” field. When overloading is enabled, this is equivalent to

get rGBA #green

setRGBAGreen :: MonadIO m => RGBA -> Float -> m ()

Set the value of the “green” field. When overloading is enabled, this is equivalent to

set rGBA [ #green := value ]

red

The intensity of the red channel from 0.0 to 1.0 inclusive

getRGBARed :: MonadIO m => RGBA -> m Float

Get the value of the “red” field. When overloading is enabled, this is equivalent to

get rGBA #red

setRGBARed :: MonadIO m => RGBA -> Float -> m ()

Set the value of the “red” field. When overloading is enabled, this is equivalent to

set rGBA [ #red := value ]