GI.Gdk.Objects.Texture

GdkTexture is the basic element used to refer to pixel data.

It is primarily meant for pixel data that will not change over multiple frames, and will be used for a long time.

There are various ways to create GdkTexture objects from a Pixbuf, or from bytes stored in memory, a file, or a [structgio.Resource].

The ownership of the pixel data is transferred to the GdkTexture instance; you can only make a copy of it, via textureDownload.

GdkTexture is an immutable object: That means you cannot change anything about it other than increasing the reference count via objectRef, and consequently, it is a thread-safe object.

Exported types

newtype Texture

Memory-managed wrapper type.

Constructors

Texture (ManagedPtr Texture)

Instances

Eq Texture

Defined in GI.Gdk.Objects.Texture

Methods

(==) :: Texture -> Texture -> Bool

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

GObject Texture

Defined in GI.Gdk.Objects.Texture

ManagedPtrNewtype Texture

Defined in GI.Gdk.Objects.Texture

Methods

toManagedPtr :: Texture -> ManagedPtr Texture

TypedObject Texture

Defined in GI.Gdk.Objects.Texture

Methods

glibType :: IO GType

HasParentTypes Texture

Defined in GI.Gdk.Objects.Texture

IsGValue (Maybe Texture)

Convert Texture to and from GValue. See toGValue and fromGValue.

Defined in GI.Gdk.Objects.Texture

Methods

gvalueGType_ :: IO GType

gvalueSet_ :: Ptr GValue -> Maybe Texture -> IO ()

gvalueGet_ :: Ptr GValue -> IO (Maybe Texture)

type ParentTypes Texture

Defined in GI.Gdk.Objects.Texture

type ParentTypes Texture = '[Object, Paintable, Icon, LoadableIcon]

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

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

Instances

(GObject o, IsDescendantOf Texture o) => IsTexture o

Defined in GI.Gdk.Objects.Texture

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

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

Methods

Click to display all available methods, including inherited ones

Methods

bindProperty, bindPropertyFull, computeConcreteSize, download, equal, forceFloating, freezeNotify, getv, hash, invalidateContents, invalidateSize, isFloating, load, loadAsync, loadFinish, notify, notifyByPspec, ref, refSink, runDispose, saveToPng, saveToPngBytes, saveToTiff, saveToTiffBytes, serialize, snapshot, stealData, stealQdata, thawNotify, toString, unref, watchClosure.

Getters

getCurrentImage, getData, getFlags, getFormat, getHeight, getIntrinsicAspectRatio, getIntrinsicHeight, getIntrinsicWidth, getProperty, getQdata, getWidth.

Setters

setData, setDataFull, setProperty.

download

textureDownload

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

texture: a GdkTexture

-> Ptr Word8

data: pointer to enough memory to be filled with the downloaded data of texture

-> CSize

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);

For more flexible download capabilities, see [structgdk.TextureDownloader].

getFormat

textureGetFormat

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

self: a GdkTexture

-> m MemoryFormat

Returns: the preferred format for the texture's data

Gets the memory format most closely associated with the data of the texture.

Note that it may not be an exact match for texture data stored on the GPU or with compression.

The format can give an indication about the bit depth and opacity of the texture and is useful to determine the best format for downloading the texture.

Since: 4.10

getHeight

textureGetHeight

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

texture: a GdkTexture

-> m Int32

Returns: the height of the GdkTexture

Returns the height of the texture, in pixels.

getWidth

textureGetWidth

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

texture: a GdkTexture

-> m Int32

Returns: the width of the GdkTexture

Returns the width of texture, in pixels.

newForPixbuf

textureNewForPixbuf

Arguments

:: (HasCallStack, MonadIO m, IsPixbuf a)

=> a

pixbuf: a GdkPixbuf

-> m Texture

Returns: a new GdkTexture

Creates a new texture object representing the GdkPixbuf.

This function is threadsafe, so that you can e.g. use GTask and taskRunInThread to avoid blocking the main thread while loading a big image.

newFromBytes

textureNewFromBytes

Arguments

:: (HasCallStack, MonadIO m)

=> Bytes

bytes: a GBytes containing the data to load

-> m Texture

Returns: A newly-created GdkTexture (Can throw GError)

Creates a new texture by loading an image from memory,

The file format is detected automatically. The supported formats are PNG, JPEG and TIFF, though more formats might be available.

If Nothing is returned, then error will be set.

This function is threadsafe, so that you can e.g. use GTask and taskRunInThread to avoid blocking the main thread while loading a big image.

Since: 4.6

newFromFile

textureNewFromFile

Arguments

:: (HasCallStack, MonadIO m, IsFile a)

=> a

file: GFile to load

-> m Texture

Returns: A newly-created GdkTexture (Can throw GError)

Creates a new texture by loading an image from a file.

The file format is detected automatically. The supported formats are PNG, JPEG and TIFF, though more formats might be available.

If Nothing is returned, then error will be set.

This function is threadsafe, so that you can e.g. use GTask and taskRunInThread to avoid blocking the main thread while loading a big image.

newFromFilename

textureNewFromFilename

Arguments

:: (HasCallStack, MonadIO m)

=> [Char]

path: the filename to load

-> m Texture

Returns: A newly-created GdkTexture (Can throw GError)

Creates a new texture by loading an image from a file.

The file format is detected automatically. The supported formats are PNG, JPEG and TIFF, though more formats might be available.

If Nothing is returned, then error will be set.

This function is threadsafe, so that you can e.g. use GTask and taskRunInThread to avoid blocking the main thread while loading a big image.

Since: 4.6

newFromResource

textureNewFromResource

Arguments

:: (HasCallStack, MonadIO m)

=> Text

resourcePath: the path of the resource file

-> m Texture

Returns: A newly-created GdkTexture

Creates a new texture by loading an image from a resource.

The file format is detected automatically. The supported formats are PNG and JPEG, though more formats might be available.

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.

This function is threadsafe, so that you can e.g. use GTask and taskRunInThread to avoid blocking the main thread while loading a big image.

saveToPng

textureSaveToPng

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

texture: a GdkTexture

-> [Char]

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 use textureSaveToPngBytes or look into the gdk-pixbuf library.

saveToPngBytes

textureSaveToPngBytes

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

texture: a GdkTexture

-> m Bytes

Returns: a newly allocated GBytes containing PNG data

Store the given texture in memory as a PNG file.

Use textureNewFromBytes to read it back.

If you want to serialize a texture, this is a convenient and portable way to do that.

If you need more control over the generated image, such as attaching metadata, you should look into an image handling library such as the gdk-pixbuf library.

If you are dealing with high dynamic range float data, you might also want to consider textureSaveToTiffBytes instead.

Since: 4.6

saveToTiff

textureSaveToTiff

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

texture: a GdkTexture

-> [Char]

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 TIFF file.

GTK will attempt to store data without loss.

Since: 4.6

saveToTiffBytes

textureSaveToTiffBytes

Arguments

:: (HasCallStack, MonadIO m, IsTexture a)

=> a

texture: a GdkTexture

-> m Bytes

Returns: a newly allocated GBytes containing TIFF data

Store the given texture in memory as a TIFF file.

Use textureNewFromBytes to read it back.

This function is intended to store a representation of the texture's data that is as accurate as possible. This is particularly relevant when working with high dynamic range images and floating-point texture data.

If that is not your concern and you are interested in a smaller size and a more portable format, you might want to use textureSaveToPngBytes.

Since: 4.6

Properties

height

The height of the texture, in pixels.

constructTextureHeight :: (IsTexture o, MonadIO m) => Int32 -> m (GValueConstruct o)

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

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

get texture #height

width

The width of the texture, in pixels.

constructTextureWidth :: (IsTexture o, MonadIO m) => Int32 -> m (GValueConstruct o)

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

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

get texture #width