Copyright	Will Thompson Iñaki García Etxebarria and Jonas Platte
License	LGPL-2.1
Maintainer	Iñaki García Etxebarria
Safe Haskell	None
Language	Haskell2010

GI.Gdk.Objects.Texture

Contents

Exported types
Methods
Properties
- height
- width

Description

A GdkTexture represents image data that can be displayed on screen.

There are various ways to create GdkTexture objects from a Pixbuf or a cairo surface, or other pixel data.

An important aspect of GdkTextures is that they are immutable - once the image data has been wrapped in a GdkTexture, it may be uploaded to the GPU or used in other ways that make it impractical to allow modification.

Synopsis

newtype Texture = Texture (ManagedPtr Texture)
class (GObject o, IsDescendantOf Texture o) => IsTexture o
toTexture :: (MonadIO m, IsTexture o) => o -> m Texture
noTexture :: Maybe Texture
textureDownload :: (HasCallStack, MonadIO m, IsTexture a) => a -> Ptr Word8 -> Word64 -> m ()
textureGetHeight :: (HasCallStack, MonadIO m, IsTexture a) => a -> m Int32
textureGetWidth :: (HasCallStack, MonadIO m, IsTexture a) => a -> m Int32
textureNewForPixbuf :: (HasCallStack, MonadIO m, IsPixbuf a) => a -> m Texture
textureNewFromFile :: (HasCallStack, MonadIO m, IsFile a) => a -> m Texture
textureNewFromResource :: (HasCallStack, MonadIO m) => Text -> m Texture
textureSaveToPng :: (HasCallStack, MonadIO m, IsTexture a) => a -> Text -> m Bool
constructTextureHeight :: IsTexture o => Int32 -> IO (GValueConstruct o)
getTextureHeight :: (MonadIO m, IsTexture o) => o -> m Int32
constructTextureWidth :: IsTexture o => Int32 -> IO (GValueConstruct o)
getTextureWidth :: (MonadIO m, IsTexture o) => o -> m Int32

Exported types

newtype Texture Source #

Memory-managed wrapper type.

Constructors

Texture (ManagedPtr Texture)

Instances

Instances details

Eq Texture Source #
Instance details Defined in GI.Gdk.Objects.Texture Methods (==) :: Texture -> Texture -> Bool # (/=) :: Texture -> Texture -> Bool #
GObject Texture Source #
Instance details Defined in GI.Gdk.Objects.Texture Methods gobjectType :: IO GType #
IsGValue Texture Source #	Convert `Texture` to and from `GValue` with `toGValue` and `fromGValue`.
Instance details Defined in GI.Gdk.Objects.Texture Methods toGValue :: Texture -> IO GValue # fromGValue :: GValue -> IO Texture #
HasParentTypes Texture Source #
Instance details Defined in GI.Gdk.Objects.Texture
type ParentTypes Texture Source #
Instance details Defined in GI.Gdk.Objects.Texture type ParentTypes Texture = '[Object, Paintable]

class (GObject o, IsDescendantOf Texture o) => IsTexture o Source #

Type class for types which can be safely cast to Texture, for instance with toTexture.

Instances

Instances details

(GObject o, IsDescendantOf Texture o) => IsTexture o Source #
Instance details Defined in GI.Gdk.Objects.Texture

toTexture :: (MonadIO m, IsTexture o) => o -> m Texture Source #

Cast to Texture, for types for which this is known to be safe. For general casts, use castTo.

noTexture :: Maybe Texture Source #

A convenience alias for Nothing :: Maybe Texture.

Methods

Overloaded methods

download

textureDownload Source #

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)
=> a	`texture`: a `Texture`
-> Ptr Word8	`data`: pointer to enough memory to be filled with the downloaded data of `texture`
-> Word64	`stride`: rowstride in bytes
-> m ()

Downloads the texture into local memory. This may be an expensive operation, as the actual texture data may reside on a GPU or on a remote display server.

The data format of the downloaded data is equivalent to FormatArgb32, so every downloaded pixel requires 4 bytes of memory.

Downloading a texture into a Cairo image surface:

C code

surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
                                      gdk_texture_get_width (texture),
                                      gdk_texture_get_height (texture));
gdk_texture_download (texture,
                      cairo_image_surface_get_data (surface),
                      cairo_image_surface_get_stride (surface));
cairo_surface_mark_dirty (surface);

getHeight

textureGetHeight Source #

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)
=> a	`texture`: a `Texture`
-> m Int32	Returns: the height of the `Texture`

Returns the height of the texture.

getWidth

textureGetWidth Source #

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)
=> a	`texture`: a `Texture`
-> m Int32	Returns: the width of the `Texture`

Returns the width of texture.

newForPixbuf

textureNewForPixbuf Source #

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)
=> a	`pixbuf`: a `Pixbuf`
-> m Texture	Returns: a new `Texture`

Creates a new texture object representing the GdkPixbuf.

newFromFile

textureNewFromFile Source #

Arguments

:: (HasCallStack, MonadIO m, IsFile a)
=> a	`file`: `File` to load
-> m Texture	Returns: A newly-created `Texture` or `Nothing` if an error occured. (Can throw `GError`)

Creates a new texture by loading an image from a file. The file format is detected automatically. If Nothing is returned, then error will be set.

newFromResource

textureNewFromResource Source #

Arguments

:: (HasCallStack, MonadIO m)
=> Text	`resourcePath`: the path of the resource file
-> m Texture	Returns: A newly-created texture

Creates a new texture by loading an image from a resource. The file format is detected automatically.

It is a fatal error if resourcePath does not specify a valid image resource and the program will abort if that happens. If you are unsure about the validity of a resource, use textureNewFromFile to load it.

saveToPng

textureSaveToPng Source #

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)
=> a	`texture`: a `Texture`
-> Text	`filename`: the filename to store to
-> m Bool	Returns: `True` if saving succeeded, `False` on failure.

Store the given texture to the filename as a PNG file.

This is a utility function intended for debugging and testing. If you want more control over formats, proper error handling or want to store to a File or other location, you might want to look into using the gdk-pixbuf library.

Properties

height

The height of the texture.

constructTextureHeight :: IsTexture o => Int32 -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “height” property. This is rarely needed directly, but it is used by new.

getTextureHeight :: (MonadIO m, IsTexture o) => o -> m Int32 Source #

Get the value of the “height” property. When overloading is enabled, this is equivalent to

get texture #height

width

The width of the texture.

constructTextureWidth :: IsTexture o => Int32 -> IO (GValueConstruct o) Source #

Construct a GValueConstruct with valid value for the “width” property. This is rarely needed directly, but it is used by new.

getTextureWidth :: (MonadIO m, IsTexture o) => o -> m Int32 Source #

Get the value of the “width” property. When overloading is enabled, this is equivalent to

get texture #width