gdkpixbuf

package
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 Go to latest Published: Feb 26, 2026 License: MIT Imports: 9 Imported by: 2

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Overview

Package gdkpixbuf was automatically generated by github.com/jwijenbergh/puregotk DO NOT EDIT

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Package gdkpixbuf was automatically generated by github.com/jwijenbergh/puregotk DO NOT EDIT

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Index

Constants

View Source 
const (
	// Major version of gdk-pixbuf library, that is the "0" in
	// "0.8.2" for example.
	PIXBUF_MAJOR int32 = 2
	// Micro version of gdk-pixbuf library, that is the "2" in
	// "0.8.2" for example.
	PIXBUF_MICRO int32 = 4
	// Minor version of gdk-pixbuf library, that is the "8" in
	// "0.8.2" for example.
	PIXBUF_MINOR int32 = 44
	// Contains the full version of GdkPixbuf as a string.
	//
	// This is the version being compiled against; contrast with
	// `gdk_pixbuf_version`.
	PIXBUF_VERSION string = "2.44.4"
)

Variables

This section is empty.

Functions

func ColorspaceGLibType 

func ColorspaceGLibType() types.GType

func InterpTypeGLibType 

func InterpTypeGLibType() types.GType

func PixbufAlphaModeGLibType 

func PixbufAlphaModeGLibType() types.GType

func PixbufAnimationGLibType 

func PixbufAnimationGLibType() types.GType

func PixbufAnimationIterGLibType 

func PixbufAnimationIterGLibType() types.GType

func PixbufAnimationNewFromStreamAsync 

func PixbufAnimationNewFromStreamAsync(StreamVar *gio.InputStream, CancellableVar *gio.Cancellable, CallbackVar *gio.AsyncReadyCallback, UserDataVar uintptr)

Creates a new animation by asynchronously loading an image from an input stream.

For more details see gdk_pixbuf_new_from_stream(), which is the synchronous version of this function.

When the operation is finished, `callback` will be called in the main thread. You can then call gdk_pixbuf_animation_new_from_stream_finish() to get the result of the operation.

func PixbufCalculateRowstride 

func PixbufCalculateRowstride(ColorspaceVar Colorspace, HasAlphaVar bool, BitsPerSampleVar int32, WidthVar int32, HeightVar int32) int32

Calculates the rowstride that an image created with those values would have.

This function is useful for front-ends and backends that want to check image values without needing to create a `GdkPixbuf`.

func PixbufErrorGLibType 

func PixbufErrorGLibType() types.GType

func PixbufErrorQuark 

func PixbufErrorQuark() glib.Quark

func PixbufFormatGLibType 

func PixbufFormatGLibType() types.GType

func PixbufGLibType 

func PixbufGLibType() types.GType

func PixbufGetFileInfoAsync 

func PixbufGetFileInfoAsync(FilenameVar string, CancellableVar *gio.Cancellable, CallbackVar *gio.AsyncReadyCallback, UserDataVar uintptr)

Asynchronously parses an image file far enough to determine its format and size.

For more details see gdk_pixbuf_get_file_info(), which is the synchronous version of this function.

When the operation is finished, @callback will be called in the main thread. You can then call gdk_pixbuf_get_file_info_finish() to get the result of the operation.

func PixbufGetFormats 

func PixbufGetFormats() *glib.SList

Obtains the available information about the image formats supported by GdkPixbuf.

func PixbufInitModules 

func PixbufInitModules(PathVar string) (bool, error)

Initalizes the gdk-pixbuf loader modules referenced by the `loaders.cache` file present inside that directory.

This is to be used by applications that want to ship certain loaders in a different location from the system ones.

This is needed when the OS or runtime ships a minimal number of loaders so as to reduce the potential attack surface of carefully crafted image files, especially for uncommon file types. Applications that require broader image file types coverage, such as image viewers, would be expected to ship the gdk-pixbuf modules in a separate location, bundled with the application in a separate directory from the OS or runtime- provided modules.

func PixbufLoaderGLibType 

func PixbufLoaderGLibType() types.GType

func PixbufNewFromStreamAsync 

func PixbufNewFromStreamAsync(StreamVar *gio.InputStream, CancellableVar *gio.Cancellable, CallbackVar *gio.AsyncReadyCallback, UserDataVar uintptr)

Creates a new pixbuf by asynchronously loading an image from an input stream.

For more details see gdk_pixbuf_new_from_stream(), which is the synchronous version of this function.

When the operation is finished, @callback will be called in the main thread. You can then call gdk_pixbuf_new_from_stream_finish() to get the result of the operation.

func PixbufNewFromStreamAtScaleAsync 

func PixbufNewFromStreamAtScaleAsync(StreamVar *gio.InputStream, WidthVar int32, HeightVar int32, PreserveAspectRatioVar bool, CancellableVar *gio.Cancellable, CallbackVar *gio.AsyncReadyCallback, UserDataVar uintptr)

Creates a new pixbuf by asynchronously loading an image from an input stream.

For more details see gdk_pixbuf_new_from_stream_at_scale(), which is the synchronous version of this function.

When the operation is finished, @callback will be called in the main thread. You can then call gdk_pixbuf_new_from_stream_finish() to get the result of the operation.

func PixbufNonAnimGLibType 

func PixbufNonAnimGLibType() types.GType

func PixbufRotationGLibType 

func PixbufRotationGLibType() types.GType

func PixbufSaveToStreamFinish 

func PixbufSaveToStreamFinish(AsyncResultVar gio.AsyncResult) (bool, error)

Finishes an asynchronous pixbuf save operation started with gdk_pixbuf_save_to_stream_async().

func PixbufSimpleAnimGLibType 

func PixbufSimpleAnimGLibType() types.GType

func PixbufSimpleAnimIterGLibType 

func PixbufSimpleAnimIterGLibType() types.GType

Types

type Colorspace 

type Colorspace int

This enumeration defines the color spaces that are supported by the gdk-pixbuf library.

Currently only RGB is supported. 

const (

	// Indicates a red/green/blue additive color space.
	GdkColorspaceRgbValue Colorspace = 0
)

type InterpType 

type InterpType int

Interpolation modes for scaling functions.

The `GDK_INTERP_NEAREST` mode is the fastest scaling method, but has horrible quality when scaling down; `GDK_INTERP_BILINEAR` is the best choice if you aren't sure what to choose, it has a good speed/quality balance.

**Note**: Cubic filtering is missing from the list; hyperbolic interpolation is just as fast and results in higher quality. 

const (

	// Nearest neighbor sampling; this is the fastest
	//  and lowest quality mode. Quality is normally unacceptable when scaling
	//  down, but may be OK when scaling up.
	GdkInterpNearestValue InterpType = 0
	// This is an accurate simulation of the PostScript
	//  image operator without any interpolation enabled.  Each pixel is
	//  rendered as a tiny parallelogram of solid color, the edges of which
	//  are implemented with antialiasing.  It resembles nearest neighbor for
	//  enlargement, and bilinear for reduction.
	GdkInterpTilesValue InterpType = 1
	// Best quality/speed balance; use this mode by
	//  default. Bilinear interpolation.  For enlargement, it is
	//  equivalent to point-sampling the ideal bilinear-interpolated image.
	//  For reduction, it is equivalent to laying down small tiles and
	//  integrating over the coverage area.
	GdkInterpBilinearValue InterpType = 2
	// This is the slowest and highest quality
	//  reconstruction function. It is derived from the hyperbolic filters in
	//  Wolberg's "Digital Image Warping", and is formally defined as the
	//  hyperbolic-filter sampling the ideal hyperbolic-filter interpolated
	//  image (the filter is designed to be idempotent for 1:1 pixel mapping).
	//  **Deprecated**: this interpolation filter is deprecated, as in reality
	//  it has a lower quality than the @GDK_INTERP_BILINEAR filter
	//  (Since: 2.38)
	GdkInterpHyperValue InterpType = 3
)

type Pixbuf 

type Pixbuf struct {
	gobject.Object
}

A pixel buffer.

`GdkPixbuf` contains information about an image's pixel data, its color space, bits per sample, width and height, and the rowstride (the number of bytes between the start of one row and the start of the next).

## Creating new `GdkPixbuf`

The most basic way to create a pixbuf is to wrap an existing pixel buffer with a [[email protected]] instance. You can use the [`[email protected]_from_data`] function to do this.

Every time you create a new `GdkPixbuf` instance for some data, you will need to specify the destroy notification function that will be called when the data buffer needs to be freed; this will happen when a `GdkPixbuf` is finalized by the reference counting functions. If you have a chunk of static data compiled into your application, you can pass in `NULL` as the destroy notification function so that the data will not be freed.

The [`[email protected]`] constructor function can be used as a convenience to create a pixbuf with an empty buffer; this is equivalent to allocating a data buffer using `malloc()` and then wrapping it with `gdk_pixbuf_new_from_data()`. The `gdk_pixbuf_new()` function will compute an optimal rowstride so that rendering can be performed with an efficient algorithm.

You can also copy an existing pixbuf with the [[email protected]] function. This is not the same as just acquiring a reference to the old pixbuf instance: the copy function will actually duplicate the pixel data in memory and create a new [class@Pixbuf] instance for it.

## Reference counting

`GdkPixbuf` structures are reference counted. This means that an application can share a single pixbuf among many parts of the code. When a piece of the program needs to use a pixbuf, it should acquire a reference to it by calling `g_object_ref()`; when it no longer needs the pixbuf, it should release the reference it acquired by calling `g_object_unref()`. The resources associated with a `GdkPixbuf` will be freed when its reference count drops to zero. Newly-created `GdkPixbuf` instances start with a reference count of one.

## Image Data

Image data in a pixbuf is stored in memory in an uncompressed, packed format. Rows in the image are stored top to bottom, and in each row pixels are stored from left to right.

There may be padding at the end of a row.

The "rowstride" value of a pixbuf, as returned by [`[email protected]_rowstride`], indicates the number of bytes between rows.

**NOTE**: If you are copying raw pixbuf data with `memcpy()` note that the last row in the pixbuf may not be as wide as the full rowstride, but rather just as wide as the pixel data needs to be; that is: it is unsafe to do `memcpy (dest, pixels, rowstride * height)` to copy a whole pixbuf. Use [[email protected]] instead, or compute the width in bytes of the last row as:

```c last_row = width * ((n_channels * bits_per_sample + 7) / 8); ```

The same rule applies when iterating over each row of a `GdkPixbuf` pixels array.

The following code illustrates a simple `put_pixel()` function for RGB pixbufs with 8 bits per channel with an alpha channel.

```c static void put_pixel (GdkPixbuf *pixbuf, 

           int x,
	   int y,
	   guchar red,
	   guchar green,
	   guchar blue,
	   guchar alpha)

{
  int n_channels = gdk_pixbuf_get_n_channels (pixbuf);

  // Ensure that the pixbuf is valid
  g_assert (gdk_pixbuf_get_colorspace (pixbuf) == GDK_COLORSPACE_RGB);
  g_assert (gdk_pixbuf_get_bits_per_sample (pixbuf) == 8);
  g_assert (gdk_pixbuf_get_has_alpha (pixbuf));
  g_assert (n_channels == 4);

  int width = gdk_pixbuf_get_width (pixbuf);
  int height = gdk_pixbuf_get_height (pixbuf);

  // Ensure that the coordinates are in a valid range
  g_assert (x >= 0 && x < width);
  g_assert (y >= 0 && y < height);

  int rowstride = gdk_pixbuf_get_rowstride (pixbuf);

  // The pixel buffer in the GdkPixbuf instance
  guchar *pixels = gdk_pixbuf_get_pixels (pixbuf);

  // The pixel we wish to modify
  guchar *p = pixels + y * rowstride + x * n_channels;
  p[0] = red;
  p[1] = green;
  p[2] = blue;
  p[3] = alpha;
}

```

## Loading images

The `GdkPixBuf` class provides a simple mechanism for loading an image from a file in synchronous and asynchronous fashion.

For GUI applications, it is recommended to use the asynchronous stream API to avoid blocking the control flow of the application.

Additionally, `GdkPixbuf` provides the [[email protected]`] API for progressive image loading.

## Saving images

The `GdkPixbuf` class provides methods for saving image data in a number of file formats. The formatted data can be written to a file or to a memory buffer. `GdkPixbuf` can also call a user-defined callback on the data, which allows to e.g. write the image to a socket or store it in a database.

func NewPixbuf 

func NewPixbuf(ColorspaceVar Colorspace, HasAlphaVar bool, BitsPerSampleVar int32, WidthVar int32, HeightVar int32) *Pixbuf

Creates a new `GdkPixbuf` structure and allocates a buffer for it.

If the allocation of the buffer failed, this function will return `NULL`.

The buffer has an optimal rowstride. Note that the buffer is not cleared; you will have to fill it completely yourself.

func NewPixbufFromBytes 

func NewPixbufFromBytes(DataVar *glib.Bytes, ColorspaceVar Colorspace, HasAlphaVar bool, BitsPerSampleVar int32, WidthVar int32, HeightVar int32, RowstrideVar int32) *Pixbuf

Creates a new #GdkPixbuf out of in-memory readonly image data.

Currently only RGB images with 8 bits per sample are supported.

This is the `GBytes` variant of gdk_pixbuf_new_from_data(), useful for language bindings.

func NewPixbufFromData 

func NewPixbufFromData(DataVar []byte, ColorspaceVar Colorspace, HasAlphaVar bool, BitsPerSampleVar int32, WidthVar int32, HeightVar int32, RowstrideVar int32, DestroyFnVar *PixbufDestroyNotify, DestroyFnDataVar uintptr) *Pixbuf

Creates a new #GdkPixbuf out of in-memory image data.

Currently only RGB images with 8 bits per sample are supported.

Since you are providing a pre-allocated pixel buffer, you must also specify a way to free that data. This is done with a function of type `GdkPixbufDestroyNotify`. When a pixbuf created with is finalized, your destroy notification function will be called, and it is its responsibility to free the pixel array.

See also: [[email protected]_from_bytes]

func NewPixbufFromFile 

func NewPixbufFromFile(FilenameVar string) (*Pixbuf, error)

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

The file format is detected automatically.

If `NULL` is returned, then @error will be set. Possible errors are:

  • the file could not be opened
  • there is no loader for the file's format
  • there is not enough memory to allocate the image buffer
  • the image buffer contains invalid data

The error domains are `GDK_PIXBUF_ERROR` and `G_FILE_ERROR`.

func NewPixbufFromFileAtScale 

func NewPixbufFromFileAtScale(FilenameVar string, WidthVar int32, HeightVar int32, PreserveAspectRatioVar bool) (*Pixbuf, error)

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

The file format is detected automatically.

If `NULL` is returned, then @error will be set. Possible errors are:

  • the file could not be opened
  • there is no loader for the file's format
  • there is not enough memory to allocate the image buffer
  • the image buffer contains invalid data

The error domains are `GDK_PIXBUF_ERROR` and `G_FILE_ERROR`.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio.

When preserving the aspect ratio, a `width` of -1 will cause the image to be scaled to the exact given height, and a `height` of -1 will cause the image to be scaled to the exact given width. When not preserving aspect ratio, a `width` or `height` of -1 means to not scale the image at all in that dimension. Negative values for `width` and `height` are allowed since 2.8.

func NewPixbufFromFileAtSize 

func NewPixbufFromFileAtSize(FilenameVar string, WidthVar int32, HeightVar int32) (*Pixbuf, error)

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

The file format is detected automatically.

If `NULL` is returned, then @error will be set. Possible errors are:

  • the file could not be opened
  • there is no loader for the file's format
  • there is not enough memory to allocate the image buffer
  • the image buffer contains invalid data

The error domains are `GDK_PIXBUF_ERROR` and `G_FILE_ERROR`.

The image will be scaled to fit in the requested size, preserving the image's aspect ratio. Note that the returned pixbuf may be smaller than `width` x `height`, if the aspect ratio requires it. To load and image at the requested size, regardless of aspect ratio, use [[email protected]_from_file_at_scale].

func NewPixbufFromInline 

func NewPixbufFromInline(DataLengthVar int32, DataVar []byte, CopyPixelsVar bool) (*Pixbuf, error)

Creates a `GdkPixbuf` from a flat representation that is suitable for storing as inline data in a program.

This is useful if you want to ship a program with images, but don't want to depend on any external files.

GdkPixbuf ships with a program called `gdk-pixbuf-csource`, which allows for conversion of `GdkPixbuf`s into such a inline representation.

In almost all cases, you should pass the `--raw` option to `gdk-pixbuf-csource`. A sample invocation would be:

``` gdk-pixbuf-csource --raw --name=myimage_inline myimage.png ```

For the typical case where the inline pixbuf is read-only static data, you don't need to copy the pixel data unless you intend to write to it, so you can pass `FALSE` for `copy_pixels`. If you pass `--rle` to `gdk-pixbuf-csource`, a copy will be made even if `copy_pixels` is `FALSE`, so using this option is generally a bad idea.

If you create a pixbuf from const inline data compiled into your program, it's probably safe to ignore errors and disable length checks, since things will always succeed:

```c pixbuf = gdk_pixbuf_new_from_inline (-1, myimage_inline, FALSE, NULL); ```

For non-const inline data, you could get out of memory. For untrusted inline data located at runtime, you could have corrupt inline data in addition.

func NewPixbufFromResource 

func NewPixbufFromResource(ResourcePathVar string) (*Pixbuf, error)

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

The file format is detected automatically. If `NULL` is returned, then @error will be set.

func NewPixbufFromResourceAtScale 

func NewPixbufFromResourceAtScale(ResourcePathVar string, WidthVar int32, HeightVar int32, PreserveAspectRatioVar bool) (*Pixbuf, error)

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

The file format is detected automatically. If `NULL` is returned, then @error will be set.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio. When preserving the aspect ratio, a @width of -1 will cause the image to be scaled to the exact given height, and a @height of -1 will cause the image to be scaled to the exact given width. When not preserving aspect ratio, a @width or @height of -1 means to not scale the image at all in that dimension.

The stream is not closed.

func NewPixbufFromStream 

func NewPixbufFromStream(StreamVar *gio.InputStream, CancellableVar *gio.Cancellable) (*Pixbuf, error)

Creates a new pixbuf by loading an image from an input stream.

The file format is detected automatically.

If `NULL` is returned, then `error` will be set.

The `cancellable` can be used to abort the operation from another thread. If the operation was cancelled, the error `G_IO_ERROR_CANCELLED` will be returned. Other possible errors are in the `GDK_PIXBUF_ERROR` and `G_IO_ERROR` domains.

The stream is not closed.

func NewPixbufFromStreamAtScale 

func NewPixbufFromStreamAtScale(StreamVar *gio.InputStream, WidthVar int32, HeightVar int32, PreserveAspectRatioVar bool, CancellableVar *gio.Cancellable) (*Pixbuf, error)

Creates a new pixbuf by loading an image from an input stream.

The file format is detected automatically. If `NULL` is returned, then @error will be set. The @cancellable can be used to abort the operation from another thread. If the operation was cancelled, the error `G_IO_ERROR_CANCELLED` will be returned. Other possible errors are in the `GDK_PIXBUF_ERROR` and `G_IO_ERROR` domains.

The image will be scaled to fit in the requested size, optionally preserving the image's aspect ratio.

When preserving the aspect ratio, a `width` of -1 will cause the image to be scaled to the exact given height, and a `height` of -1 will cause the image to be scaled to the exact given width. If both `width` and `height` are given, this function will behave as if the smaller of the two values is passed as -1.

When not preserving aspect ratio, a `width` or `height` of -1 means to not scale the image at all in that dimension.

The stream is not closed.

func NewPixbufFromStreamFinish 

func NewPixbufFromStreamFinish(AsyncResultVar gio.AsyncResult) (*Pixbuf, error)

Finishes an asynchronous pixbuf creation operation started with gdk_pixbuf_new_from_stream_async().

func NewPixbufFromXpmData 

func NewPixbufFromXpmData(DataVar []string) *Pixbuf

Creates a new pixbuf by parsing XPM data in memory.

This data is commonly the result of including an XPM file into a program's C source.

func PixbufNewFromInternalPtr 

func PixbufNewFromInternalPtr(ptr uintptr) *Pixbuf

func (*Pixbuf) AddAlpha 

func (x *Pixbuf) AddAlpha(SubstituteColorVar bool, RVar byte, GVar byte, BVar byte) *Pixbuf

Takes an existing pixbuf and adds an alpha channel to it.

If the existing pixbuf already had an alpha channel, the channel values are copied from the original; otherwise, the alpha channel is initialized to 255 (full opacity).

If `substitute_color` is `TRUE`, then the color specified by the (`r`, `g`, `b`) arguments will be assigned zero opacity. That is, if you pass `(255, 255, 255)` for the substitute color, all white pixels will become fully transparent.

If `substitute_color` is `FALSE`, then the (`r`, `g`, `b`) arguments will be ignored.

func (*Pixbuf) ApplyEmbeddedOrientation 

func (x *Pixbuf) ApplyEmbeddedOrientation() *Pixbuf

Takes an existing pixbuf and checks for the presence of an associated "orientation" option.

The orientation option may be provided by the JPEG loader (which reads the exif orientation tag) or the TIFF loader (which reads the TIFF orientation tag, and compensates it for the partial transforms performed by libtiff).

If an orientation option/tag is present, the appropriate transform will be performed so that the pixbuf is oriented correctly.

func (*Pixbuf) Composite 

func (x *Pixbuf) Composite(DestVar *Pixbuf, DestXVar int32, DestYVar int32, DestWidthVar int32, DestHeightVar int32, OffsetXVar float64, OffsetYVar float64, ScaleXVar float64, ScaleYVar float64, InterpTypeVar InterpType, OverallAlphaVar int32)

Creates a transformation of the source image @src by scaling by @scale_x and @scale_y then translating by @offset_x and @offset_y.

This gives an image in the coordinates of the destination pixbuf. The rectangle (@dest_x, @dest_y, @dest_width, @dest_height) is then alpha blended onto the corresponding rectangle of the original destination image.

When the destination rectangle contains parts not in the source image, the data at the edges of the source image is replicated to infinity.

![](composite.png)

func (*Pixbuf) CompositeColor 

func (x *Pixbuf) CompositeColor(DestVar *Pixbuf, DestXVar int32, DestYVar int32, DestWidthVar int32, DestHeightVar int32, OffsetXVar float64, OffsetYVar float64, ScaleXVar float64, ScaleYVar float64, InterpTypeVar InterpType, OverallAlphaVar int32, CheckXVar int32, CheckYVar int32, CheckSizeVar int32, Color1Var uint32, Color2Var uint32)

Creates a transformation of the source image @src by scaling by @scale_x and @scale_y then translating by @offset_x and @offset_y, then alpha blends the rectangle (@dest_x ,@dest_y, @dest_width, @dest_height) of the resulting image with a checkboard of the colors @color1 and @color2 and renders it onto the destination image.

If the source image has no alpha channel, and @overall_alpha is 255, a fast path is used which omits the alpha blending and just performs the scaling.

See gdk_pixbuf_composite_color_simple() for a simpler variant of this function suitable for many tasks.

func (*Pixbuf) CompositeColorSimple 

func (x *Pixbuf) CompositeColorSimple(DestWidthVar int32, DestHeightVar int32, InterpTypeVar InterpType, OverallAlphaVar int32, CheckSizeVar int32, Color1Var uint32, Color2Var uint32) *Pixbuf

Creates a new pixbuf by scaling `src` to `dest_width` x `dest_height` and alpha blending the result with a checkboard of colors `color1` and `color2`.

func (*Pixbuf) Copy 

func (x *Pixbuf) Copy() *Pixbuf

Creates a new `GdkPixbuf` with a copy of the information in the specified `pixbuf`.

Note that this does not copy the options set on the original `GdkPixbuf`, use gdk_pixbuf_copy_options() for this.

func (*Pixbuf) CopyArea 

func (x *Pixbuf) CopyArea(SrcXVar int32, SrcYVar int32, WidthVar int32, HeightVar int32, DestPixbufVar *Pixbuf, DestXVar int32, DestYVar int32)

Copies a rectangular area from `src_pixbuf` to `dest_pixbuf`.

Conversion of pixbuf formats is done automatically.

If the source rectangle overlaps the destination rectangle on the same pixbuf, it will be overwritten during the copy operation. Therefore, you can not use this function to scroll a pixbuf.

func (*Pixbuf) CopyOptions 

func (x *Pixbuf) CopyOptions(DestPixbufVar *Pixbuf) bool

Copies the key/value pair options attached to a `GdkPixbuf` to another `GdkPixbuf`.

This is useful to keep original metadata after having manipulated a file. However be careful to remove metadata which you've already applied, such as the "orientation" option after rotating the image.

func (*Pixbuf) Equal 

func (x *Pixbuf) Equal(Icon2Var gio.Icon) bool

Checks if two icons are equal.

func (*Pixbuf) Fill 

func (x *Pixbuf) Fill(PixelVar uint32)

Clears a pixbuf to the given RGBA value, converting the RGBA value into the pixbuf's pixel format.

The alpha component will be ignored if the pixbuf doesn't have an alpha channel.

func (*Pixbuf) Flip 

func (x *Pixbuf) Flip(HorizontalVar bool) *Pixbuf

Flips a pixbuf horizontally or vertically and returns the result in a new pixbuf.

func (*Pixbuf) GetBitsPerSample 

func (x *Pixbuf) GetBitsPerSample() int32

Queries the number of bits per color sample in a pixbuf.

func (*Pixbuf) GetByteLength 

func (x *Pixbuf) GetByteLength() uint

Returns the length of the pixel data, in bytes.

func (*Pixbuf) GetColorspace 

func (x *Pixbuf) GetColorspace() Colorspace

Queries the color space of a pixbuf.

func (*Pixbuf) GetHasAlpha 

func (x *Pixbuf) GetHasAlpha() bool

Queries whether a pixbuf has an alpha channel (opacity information).

func (*Pixbuf) GetHeight 

func (x *Pixbuf) GetHeight() int32

Queries the height of a pixbuf.

func (*Pixbuf) GetNChannels 

func (x *Pixbuf) GetNChannels() int32

Queries the number of channels of a pixbuf.

func (*Pixbuf) GetOption 

func (x *Pixbuf) GetOption(KeyVar string) string

Looks up @key in the list of options that may have been attached to the @pixbuf when it was loaded, or that may have been attached by another function using gdk_pixbuf_set_option().

For instance, the ANI loader provides "Title" and "Artist" options. The ICO, XBM, and XPM loaders provide "x_hot" and "y_hot" hot-spot options for cursor definitions. The PNG loader provides the tEXt ancillary chunk key/value pairs as options. Since 2.12, the TIFF and JPEG loaders return an "orientation" option string that corresponds to the embedded TIFF/Exif orientation tag (if present). Since 2.32, the TIFF loader sets the "multipage" option string to "yes" when a multi-page TIFF is loaded. Since 2.32 the JPEG and PNG loaders set "x-dpi" and "y-dpi" if the file contains image density information in dots per inch. Since 2.36.6, the JPEG loader sets the "comment" option with the comment EXIF tag.

func (*Pixbuf) GetOptions 

func (x *Pixbuf) GetOptions() *glib.HashTable

Returns a `GHashTable` with a list of all the options that may have been attached to the `pixbuf` when it was loaded, or that may have been attached by another function using [[email protected]_option].

func (*Pixbuf) GetPixels 

func (x *Pixbuf) GetPixels() uintptr

Queries a pointer to the pixel data of a pixbuf.

This function will cause an implicit copy of the pixbuf data if the pixbuf was created from read-only data.

Please see the section on [image data](class.Pixbuf.html#image-data) for information about how the pixel data is stored in memory.

func (*Pixbuf) GetPixelsWithLength 

func (x *Pixbuf) GetPixelsWithLength(LengthVar *uint32) uintptr

Queries a pointer to the pixel data of a pixbuf.

This function will cause an implicit copy of the pixbuf data if the pixbuf was created from read-only data.

Please see the section on [image data](class.Pixbuf.html#image-data) for information about how the pixel data is stored in memory.

func (*Pixbuf) GetPropertyBitsPerSample 

func (x *Pixbuf) GetPropertyBitsPerSample() int32

GetPropertyBitsPerSample gets the "bits-per-sample" property. The number of bits per sample.

Currently only 8 bit per sample are supported.

func (*Pixbuf) GetPropertyHasAlpha 

func (x *Pixbuf) GetPropertyHasAlpha() bool

GetPropertyHasAlpha gets the "has-alpha" property. Whether the pixbuf has an alpha channel.

func (*Pixbuf) GetPropertyHeight 

func (x *Pixbuf) GetPropertyHeight() int32

GetPropertyHeight gets the "height" property. The number of rows of the pixbuf.

func (*Pixbuf) GetPropertyNChannels 

func (x *Pixbuf) GetPropertyNChannels() int32

GetPropertyNChannels gets the "n-channels" property. The number of samples per pixel.

Currently, only 3 or 4 samples per pixel are supported.

func (*Pixbuf) GetPropertyPixelBytes 

func (x *Pixbuf) GetPropertyPixelBytes() uintptr

GetPropertyPixelBytes gets the "pixel-bytes" property.

func (*Pixbuf) GetPropertyPixels 

func (x *Pixbuf) GetPropertyPixels() uintptr

GetPropertyPixels gets the "pixels" property. A pointer to the pixel data of the pixbuf.

func (*Pixbuf) GetPropertyRowstride 

func (x *Pixbuf) GetPropertyRowstride() int32

GetPropertyRowstride gets the "rowstride" property. The number of bytes between the start of a row and the start of the next row.

This number must (obviously) be at least as large as the width of the pixbuf.

func (*Pixbuf) GetPropertyWidth 

func (x *Pixbuf) GetPropertyWidth() int32

GetPropertyWidth gets the "width" property. The number of columns of the pixbuf.

func (*Pixbuf) GetRowstride 

func (x *Pixbuf) GetRowstride() int32

Queries the rowstride of a pixbuf, which is the number of bytes between the start of a row and the start of the next row.

func (*Pixbuf) GetWidth 

func (x *Pixbuf) GetWidth() int32

Queries the width of a pixbuf.

func (*Pixbuf) GoPointer 

func (c *Pixbuf) GoPointer() uintptr

func (*Pixbuf) Hash 

func (x *Pixbuf) Hash() uint32

Gets a hash for an icon.

func (*Pixbuf) Load 

func (x *Pixbuf) Load(SizeVar int32, TypeVar *string, CancellableVar *gio.Cancellable) (*gio.InputStream, error)

Loads a loadable icon. For the asynchronous version of this function, see g_loadable_icon_load_async().

func (*Pixbuf) LoadAsync 

func (x *Pixbuf) LoadAsync(SizeVar int32, CancellableVar *gio.Cancellable, CallbackVar *gio.AsyncReadyCallback, UserDataVar uintptr)

Loads an icon asynchronously. To finish this function, see g_loadable_icon_load_finish(). For the synchronous, blocking version of this function, see g_loadable_icon_load().

func (*Pixbuf) LoadFinish 

func (x *Pixbuf) LoadFinish(ResVar gio.AsyncResult, TypeVar *string) (*gio.InputStream, error)

Finishes an asynchronous icon load started in g_loadable_icon_load_async().

func (*Pixbuf) NewSubpixbuf 

func (x *Pixbuf) NewSubpixbuf(SrcXVar int32, SrcYVar int32, WidthVar int32, HeightVar int32) *Pixbuf

Creates a new pixbuf which represents a sub-region of `src_pixbuf`.

The new pixbuf shares its pixels with the original pixbuf, so writing to one affects both. The new pixbuf holds a reference to `src_pixbuf`, so `src_pixbuf` will not be finalized until the new pixbuf is finalized.

Note that if `src_pixbuf` is read-only, this function will force it to be mutable.

func (*Pixbuf) ReadPixelBytes 

func (x *Pixbuf) ReadPixelBytes() *glib.Bytes

Provides a #GBytes buffer containing the raw pixel data; the data must not be modified.

This function allows skipping the implicit copy that must be made if gdk_pixbuf_get_pixels() is called on a read-only pixbuf.

func (*Pixbuf) ReadPixels 

func (x *Pixbuf) ReadPixels() byte

Provides a read-only pointer to the raw pixel data.

This function allows skipping the implicit copy that must be made if gdk_pixbuf_get_pixels() is called on a read-only pixbuf.

func (*Pixbuf) Ref 

func (x *Pixbuf) Ref() *Pixbuf

Adds a reference to a pixbuf.

func (*Pixbuf) RemoveOption 

func (x *Pixbuf) RemoveOption(KeyVar string) bool

Removes the key/value pair option attached to a `GdkPixbuf`.

func (*Pixbuf) RotateSimple 

func (x *Pixbuf) RotateSimple(AngleVar PixbufRotation) *Pixbuf

Rotates a pixbuf by a multiple of 90 degrees, and returns the result in a new pixbuf.

If `angle` is 0, this function will return a copy of `src`.

func (*Pixbuf) SaturateAndPixelate 

func (x *Pixbuf) SaturateAndPixelate(DestVar *Pixbuf, SaturationVar float32, PixelateVar bool)

Modifies saturation and optionally pixelates `src`, placing the result in `dest`.

The `src` and `dest` pixbufs must have the same image format, size, and rowstride.

The `src` and `dest` arguments may be the same pixbuf with no ill effects.

If `saturation` is 1.0 then saturation is not changed. If it's less than 1.0, saturation is reduced (the image turns toward grayscale); if greater than 1.0, saturation is increased (the image gets more vivid colors).

If `pixelate` is `TRUE`, then pixels are faded in a checkerboard pattern to create a pixelated image.

func (*Pixbuf) Save 

func (x *Pixbuf) Save(FilenameVar string, TypeVar string, ErrorVar **glib.Error, varArgs ...interface{}) bool

Saves pixbuf to a file in format @type. By default, "jpeg", "png", "ico" and "bmp" are possible file formats to save in, but more formats may be installed. The list of all writable formats can be determined in the following way:

```c void add_if_writable (GdkPixbufFormat *data, GSList **list) 

{
  if (gdk_pixbuf_format_is_writable (data))
    *list = g_slist_prepend (*list, data);
}

GSList *formats = gdk_pixbuf_get_formats (); GSList *writable_formats = NULL; g_slist_foreach (formats, add_if_writable, &writable_formats); g_slist_free (formats); ```

If `error` is set, `FALSE` will be returned. Possible errors include those in the `GDK_PIXBUF_ERROR` domain and those in the `G_FILE_ERROR` domain.

The variable argument list should be `NULL`-terminated; if not empty, it should contain pairs of strings that modify the save parameters. For example:

```c gdk_pixbuf_save (pixbuf, handle, "jpeg", &error, "quality", "100", NULL); ```

Currently only few parameters exist.

JPEG images can be saved with a "quality" parameter; its value should be in the range `[0, 100]`. JPEG and PNG density can be set by setting the "x-dpi" and "y-dpi" parameters to the appropriate values in dots per inch.

Text chunks can be attached to PNG images by specifying parameters of the form "tEXt::key", where key is an ASCII string of length 1-79. The values are UTF-8 encoded strings. The PNG compression level can be specified using the "compression" parameter; it's value is in an integer in the range of `[0, 9]`.

ICC color profiles can also be embedded into PNG, JPEG and TIFF images. The "icc-profile" value should be the complete ICC profile encoded into base64.

```c char *contents; gsize length;

// icm_path is set elsewhere g_file_get_contents (icm_path, &contents, &length, NULL);

char *contents_encode = g_base64_encode ((const guchar *) contents, length);

gdk_pixbuf_save (pixbuf, handle, "png", &error, "icc-profile", contents_encode, NULL); ```

TIFF images recognize:

  1. a "bits-per-sample" option (integer) which can be either 1 for saving bi-level CCITTFAX4 images, or 8 for saving 8-bits per sample
  2. a "compression" option (integer) which can be 1 for no compression, 2 for Huffman, 5 for LZW, 7 for JPEG and 8 for DEFLATE (see the libtiff documentation and tiff.h for all supported codec values)
  3. an "icc-profile" option (zero-terminated string) containing a base64 encoded ICC color profile.

ICO images can be saved in depth 16, 24, or 32, by using the "depth" parameter. When the ICO saver is given "x_hot" and "y_hot" parameters, it produces a CUR instead of an ICO.

func (*Pixbuf) SaveToBuffer 

func (x *Pixbuf) SaveToBuffer(BufferVar *[]byte, BufferSizeVar *uint, TypeVar string, ErrorVar **glib.Error, varArgs ...interface{}) bool

Saves pixbuf to a new buffer in format `type`, which is currently "jpeg", "png", "tiff", "ico" or "bmp".

This is a convenience function that uses `gdk_pixbuf_save_to_callback()` to do the real work.

Note that the buffer is not `NUL`-terminated and may contain embedded `NUL` characters.

If @error is set, `FALSE` will be returned and @buffer will be set to `NULL`. Possible errors include those in the `GDK_PIXBUF_ERROR` domain.

See `gdk_pixbuf_save()` for more details.

func (*Pixbuf) SaveToBufferv 

func (x *Pixbuf) SaveToBufferv(BufferVar *[]byte, BufferSizeVar *uint, TypeVar string, OptionKeysVar []string, OptionValuesVar []string) (bool, error)

Vector version of `gdk_pixbuf_save_to_buffer()`.

Saves pixbuf to a new buffer in format @type, which is currently "jpeg", "tiff", "png", "ico" or "bmp".

See [[email protected]_to_buffer] for more details.

func (*Pixbuf) SaveToCallback 

func (x *Pixbuf) SaveToCallback(SaveFuncVar *PixbufSaveFunc, UserDataVar uintptr, TypeVar string, ErrorVar **glib.Error, varArgs ...interface{}) bool

Saves pixbuf in format `type` by feeding the produced data to a callback.

This function can be used when you want to store the image to something other than a file, such as an in-memory buffer or a socket.

If @error is set, `FALSE` will be returned. Possible errors include those in the `GDK_PIXBUF_ERROR` domain and whatever the save function generates.

See [[email protected]] for more details.

func (*Pixbuf) SaveToCallbackv 

func (x *Pixbuf) SaveToCallbackv(SaveFuncVar *PixbufSaveFunc, UserDataVar uintptr, TypeVar string, OptionKeysVar []string, OptionValuesVar []string) (bool, error)

Vector version of `gdk_pixbuf_save_to_callback()`.

Saves pixbuf to a callback in format @type, which is currently "jpeg", "png", "tiff", "ico" or "bmp".

If @error is set, `FALSE` will be returned.

See [[email protected]_to_callback] for more details.

func (*Pixbuf) SaveToStream 

func (x *Pixbuf) SaveToStream(StreamVar *gio.OutputStream, TypeVar string, CancellableVar *gio.Cancellable, ErrorVar **glib.Error, varArgs ...interface{}) bool

Saves `pixbuf` to an output stream.

Supported file formats are currently "jpeg", "tiff", "png", "ico" or "bmp". See `gdk_pixbuf_save_to_buffer()` for more details.

The `cancellable` can be used to abort the operation from another thread. If the operation was cancelled, the error `G_IO_ERROR_CANCELLED` will be returned. Other possible errors are in the `GDK_PIXBUF_ERROR` and `G_IO_ERROR` domains.

The stream is not closed at the end of this call.

func (*Pixbuf) SaveToStreamAsync 

func (x *Pixbuf) SaveToStreamAsync(StreamVar *gio.OutputStream, TypeVar string, CancellableVar *gio.Cancellable, CallbackVar *gio.AsyncReadyCallback, UserDataVar uintptr, varArgs ...interface{})

Saves `pixbuf` to an output stream asynchronously.

For more details see gdk_pixbuf_save_to_stream(), which is the synchronous version of this function.

When the operation is finished, `callback` will be called in the main thread.

You can then call gdk_pixbuf_save_to_stream_finish() to get the result of the operation.

func (*Pixbuf) SaveToStreamv 

func (x *Pixbuf) SaveToStreamv(StreamVar *gio.OutputStream, TypeVar string, OptionKeysVar []string, OptionValuesVar []string, CancellableVar *gio.Cancellable) (bool, error)

Saves `pixbuf` to an output stream.

Supported file formats are currently "jpeg", "tiff", "png", "ico" or "bmp".

See [[email protected]_to_stream] for more details.

func (*Pixbuf) SaveToStreamvAsync 

func (x *Pixbuf) SaveToStreamvAsync(StreamVar *gio.OutputStream, TypeVar string, OptionKeysVar []string, OptionValuesVar []string, CancellableVar *gio.Cancellable, CallbackVar *gio.AsyncReadyCallback, UserDataVar uintptr)

Saves `pixbuf` to an output stream asynchronously.

For more details see gdk_pixbuf_save_to_streamv(), which is the synchronous version of this function.

When the operation is finished, `callback` will be called in the main thread.

You can then call gdk_pixbuf_save_to_stream_finish() to get the result of the operation.

func (*Pixbuf) Savev 

func (x *Pixbuf) Savev(FilenameVar string, TypeVar string, OptionKeysVar []string, OptionValuesVar []string) (bool, error)

Vector version of `gdk_pixbuf_save()`.

Saves pixbuf to a file in `type`, which is currently "jpeg", "png", "tiff", "ico" or "bmp".

If @error is set, `FALSE` will be returned.

See [[email protected]] for more details.

func (*Pixbuf) Scale 

func (x *Pixbuf) Scale(DestVar *Pixbuf, DestXVar int32, DestYVar int32, DestWidthVar int32, DestHeightVar int32, OffsetXVar float64, OffsetYVar float64, ScaleXVar float64, ScaleYVar float64, InterpTypeVar InterpType)

Creates a transformation of the source image @src by scaling by @scale_x and @scale_y then translating by @offset_x and @offset_y, then renders the rectangle (@dest_x, @dest_y, @dest_width, @dest_height) of the resulting image onto the destination image replacing the previous contents.

Try to use gdk_pixbuf_scale_simple() first; this function is the industrial-strength power tool you can fall back to, if gdk_pixbuf_scale_simple() isn't powerful enough.

If the source rectangle overlaps the destination rectangle on the same pixbuf, it will be overwritten during the scaling which results in rendering artifacts.

func (*Pixbuf) ScaleSimple 

func (x *Pixbuf) ScaleSimple(DestWidthVar int32, DestHeightVar int32, InterpTypeVar InterpType) *Pixbuf

Create a new pixbuf containing a copy of `src` scaled to `dest_width` x `dest_height`.

This function leaves `src` unaffected.

The `interp_type` should be `GDK_INTERP_NEAREST` if you want maximum speed (but when scaling down `GDK_INTERP_NEAREST` is usually unusably ugly). The default `interp_type` should be `GDK_INTERP_BILINEAR` which offers reasonable quality and speed.

You can scale a sub-portion of `src` by creating a sub-pixbuf pointing into `src`; see [[email protected]_subpixbuf].

If `dest_width` and `dest_height` are equal to the width and height of `src`, this function will return an unscaled copy of `src`.

For more complicated scaling/alpha blending see [[email protected]] and [[email protected]].

func (*Pixbuf) Serialize 

func (x *Pixbuf) Serialize() *glib.Variant

Serializes a #GIcon into a #GVariant. An equivalent #GIcon can be retrieved back by calling g_icon_deserialize() on the returned value. As serialization will avoid using raw icon data when possible, it only makes sense to transfer the #GVariant between processes on the same machine, (as opposed to over the network), and within the same file system namespace.

func (*Pixbuf) SetGoPointer 

func (c *Pixbuf) SetGoPointer(ptr uintptr)

func (*Pixbuf) SetOption 

func (x *Pixbuf) SetOption(KeyVar string, ValueVar string) bool

Attaches a key/value pair as an option to a `GdkPixbuf`.

If `key` already exists in the list of options attached to the `pixbuf`, the new value is ignored and `FALSE` is returned.

func (*Pixbuf) SetPropertyBitsPerSample 

func (x *Pixbuf) SetPropertyBitsPerSample(value int32)

SetPropertyBitsPerSample sets the "bits-per-sample" property. The number of bits per sample.

Currently only 8 bit per sample are supported.

func (*Pixbuf) SetPropertyHasAlpha 

func (x *Pixbuf) SetPropertyHasAlpha(value bool)

SetPropertyHasAlpha sets the "has-alpha" property. Whether the pixbuf has an alpha channel.

func (*Pixbuf) SetPropertyHeight 

func (x *Pixbuf) SetPropertyHeight(value int32)

SetPropertyHeight sets the "height" property. The number of rows of the pixbuf.

func (*Pixbuf) SetPropertyNChannels 

func (x *Pixbuf) SetPropertyNChannels(value int32)

SetPropertyNChannels sets the "n-channels" property. The number of samples per pixel.

Currently, only 3 or 4 samples per pixel are supported.

func (*Pixbuf) SetPropertyPixelBytes 

func (x *Pixbuf) SetPropertyPixelBytes(value uintptr)

SetPropertyPixelBytes sets the "pixel-bytes" property.

func (*Pixbuf) SetPropertyPixels 

func (x *Pixbuf) SetPropertyPixels(value uintptr)

SetPropertyPixels sets the "pixels" property. A pointer to the pixel data of the pixbuf.

func (*Pixbuf) SetPropertyRowstride 

func (x *Pixbuf) SetPropertyRowstride(value int32)

SetPropertyRowstride sets the "rowstride" property. The number of bytes between the start of a row and the start of the next row.

This number must (obviously) be at least as large as the width of the pixbuf.

func (*Pixbuf) SetPropertyWidth 

func (x *Pixbuf) SetPropertyWidth(value int32)

SetPropertyWidth sets the "width" property. The number of columns of the pixbuf.

func (*Pixbuf) ToString 

func (x *Pixbuf) ToString() string

Generates a textual representation of @icon that can be used for serialization such as when passing @icon to a different process or saving it to persistent storage. Use g_icon_new_for_string() to get @icon back from the returned string.

The encoding of the returned string is proprietary to #GIcon except in the following two cases

  • If @icon is a #GFileIcon, the returned string is a native path (such as `/path/to/my icon.png`) without escaping if the #GFile for @icon is a native file. If the file is not native, the returned string is the result of g_file_get_uri() (such as `sftp://path/to/my%20icon.png`).

  • If @icon is a #GThemedIcon with exactly one name and no fallbacks, the encoding is simply the name (such as `network-server`).

func (*Pixbuf) Unref 

func (x *Pixbuf) Unref()

Removes a reference from a pixbuf.

type PixbufAlphaMode 

type PixbufAlphaMode int

Control the alpha channel for drawables.

These values can be passed to gdk_pixbuf_xlib_render_to_drawable_alpha() in gdk-pixbuf-xlib to control how the alpha channel of an image should be handled.

This function can create a bilevel clipping mask (black and white) and use it while painting the image.

In the future, when the X Window System gets an alpha channel extension, it will be possible to do full alpha compositing onto arbitrary drawables. For now both cases fall back to a bilevel clipping mask. 

const (

	// A bilevel clipping mask (black and white)
	//  will be created and used to draw the image.  Pixels below 0.5 opacity
	//  will be considered fully transparent, and all others will be
	//  considered fully opaque.
	GdkPixbufAlphaBilevelValue PixbufAlphaMode = 0
	// For now falls back to #GDK_PIXBUF_ALPHA_BILEVEL.
	//  In the future it will do full alpha compositing.
	GdkPixbufAlphaFullValue PixbufAlphaMode = 1
)

type PixbufAnimation 

type PixbufAnimation struct {
	gobject.Object
}

An opaque object representing an animation.

The GdkPixBuf library provides a simple mechanism to load and represent animations. An animation is conceptually a series of frames to be displayed over time.

The animation may not be represented as a series of frames internally; for example, it may be stored as a sprite and instructions for moving the sprite around a background.

To display an animation you don't need to understand its representation, however; you just ask `GdkPixbuf` what should be displayed at a given point in time.

func NewPixbufAnimationFromFile 

func NewPixbufAnimationFromFile(FilenameVar string) (*PixbufAnimation, error)

Creates a new animation by loading it from a file.

The file format is detected automatically.

If the file's format does not support multi-frame images, then an animation with a single frame will be created.

Possible errors are in the `GDK_PIXBUF_ERROR` and `G_FILE_ERROR` domains.

func NewPixbufAnimationFromResource 

func NewPixbufAnimationFromResource(ResourcePathVar string) (*PixbufAnimation, error)

Creates a new pixbuf animation by loading an image from an resource.

The file format is detected automatically. If `NULL` is returned, then @error will be set.

func NewPixbufAnimationFromStream 

func NewPixbufAnimationFromStream(StreamVar *gio.InputStream, CancellableVar *gio.Cancellable) (*PixbufAnimation, error)

Creates a new animation by loading it from an input stream.

The file format is detected automatically.

If `NULL` is returned, then @error will be set.

The @cancellable can be used to abort the operation from another thread. If the operation was cancelled, the error `G_IO_ERROR_CANCELLED` will be returned. Other possible errors are in the `GDK_PIXBUF_ERROR` and `G_IO_ERROR` domains.

The stream is not closed.

func NewPixbufAnimationFromStreamFinish 

func NewPixbufAnimationFromStreamFinish(AsyncResultVar gio.AsyncResult) (*PixbufAnimation, error)

Finishes an asynchronous pixbuf animation creation operation started with [[email protected]_from_stream_async].

func PixbufAnimationNewFromInternalPtr 

func PixbufAnimationNewFromInternalPtr(ptr uintptr) *PixbufAnimation

func (*PixbufAnimation) GetHeight 

func (x *PixbufAnimation) GetHeight() int32

Queries the height of the bounding box of a pixbuf animation.

func (*PixbufAnimation) GetIter 

func (x *PixbufAnimation) GetIter(StartTimeVar *glib.TimeVal) *PixbufAnimationIter

Get an iterator for displaying an animation.

The iterator provides the frames that should be displayed at a given time.

@start_time would normally come from g_get_current_time(), and marks the beginning of animation playback. After creating an iterator, you should immediately display the pixbuf returned by gdk_pixbuf_animation_iter_get_pixbuf(). Then, you should install a timeout (with g_timeout_add()) or by some other mechanism ensure that you'll update the image after gdk_pixbuf_animation_iter_get_delay_time() milliseconds. Each time the image is updated, you should reinstall the timeout with the new, possibly-changed delay time.

As a shortcut, if @start_time is `NULL`, the result of g_get_current_time() will be used automatically.

To update the image (i.e. possibly change the result of gdk_pixbuf_animation_iter_get_pixbuf() to a new frame of the animation), call gdk_pixbuf_animation_iter_advance().

If you're using #GdkPixbufLoader, in addition to updating the image after the delay time, you should also update it whenever you receive the area_updated signal and gdk_pixbuf_animation_iter_on_currently_loading_frame() returns `TRUE`. In this case, the frame currently being fed into the loader has received new data, so needs to be refreshed. The delay time for a frame may also be modified after an area_updated signal, for example if the delay time for a frame is encoded in the data after the frame itself. So your timeout should be reinstalled after any area_updated signal.

A delay time of -1 is possible, indicating "infinite".

func (*PixbufAnimation) GetStaticImage 

func (x *PixbufAnimation) GetStaticImage() *Pixbuf

Retrieves a static image for the animation.

If an animation is really just a plain image (has only one frame), this function returns that image.

If the animation is an animation, this function returns a reasonable image to use as a static unanimated image, which might be the first frame, or something more sophisticated depending on the file format.

If an animation hasn't loaded any frames yet, this function will return `NULL`.

func (*PixbufAnimation) GetWidth 

func (x *PixbufAnimation) GetWidth() int32

Queries the width of the bounding box of a pixbuf animation.

func (*PixbufAnimation) GoPointer 

func (c *PixbufAnimation) GoPointer() uintptr

func (*PixbufAnimation) IsStaticImage 

func (x *PixbufAnimation) IsStaticImage() bool

Checks whether the animation is a static image.

If you load a file with gdk_pixbuf_animation_new_from_file() and it turns out to be a plain, unanimated image, then this function will return `TRUE`. Use gdk_pixbuf_animation_get_static_image() to retrieve the image.

func (*PixbufAnimation) Ref 

func (x *PixbufAnimation) Ref() *PixbufAnimation

Adds a reference to an animation.

func (*PixbufAnimation) SetGoPointer 

func (c *PixbufAnimation) SetGoPointer(ptr uintptr)

func (*PixbufAnimation) Unref 

func (x *PixbufAnimation) Unref()

Removes a reference from an animation.

type PixbufAnimationClass 

type PixbufAnimationClass struct {
	ParentClass gobject.ObjectClass
	// contains filtered or unexported fields
}

Modules supporting animations must derive a type from #GdkPixbufAnimation, providing suitable implementations of the virtual functions.

func (*PixbufAnimationClass) GetGetIter 

func (x *PixbufAnimationClass) GetGetIter() func(*PixbufAnimation, *glib.TimeVal) *PixbufAnimationIter

GetGetIter gets the "get_iter" callback function. returns an iterator for the given animation.

func (*PixbufAnimationClass) GetGetSize 

func (x *PixbufAnimationClass) GetGetSize() func(*PixbufAnimation, int32, int32)

GetGetSize gets the "get_size" callback function. fills @width and @height with the frame size of the animation.

func (*PixbufAnimationClass) GetGetStaticImage 

func (x *PixbufAnimationClass) GetGetStaticImage() func(*PixbufAnimation) *Pixbuf

GetGetStaticImage gets the "get_static_image" callback function. returns a static image representing the given animation.

func (*PixbufAnimationClass) GetIsStaticImage 

func (x *PixbufAnimationClass) GetIsStaticImage() func(*PixbufAnimation) bool

GetIsStaticImage gets the "is_static_image" callback function. returns whether the given animation is just a static image.

func (*PixbufAnimationClass) GoPointer 

func (x *PixbufAnimationClass) GoPointer() uintptr

func (*PixbufAnimationClass) OverrideGetIter 

func (x *PixbufAnimationClass) OverrideGetIter(cb func(*PixbufAnimation, *glib.TimeVal) *PixbufAnimationIter)

OverrideGetIter sets the "get_iter" callback function. returns an iterator for the given animation.

func (*PixbufAnimationClass) OverrideGetSize 

func (x *PixbufAnimationClass) OverrideGetSize(cb func(*PixbufAnimation, int32, int32))

OverrideGetSize sets the "get_size" callback function. fills @width and @height with the frame size of the animation.

func (*PixbufAnimationClass) OverrideGetStaticImage 

func (x *PixbufAnimationClass) OverrideGetStaticImage(cb func(*PixbufAnimation) *Pixbuf)

OverrideGetStaticImage sets the "get_static_image" callback function. returns a static image representing the given animation.

func (*PixbufAnimationClass) OverrideIsStaticImage 

func (x *PixbufAnimationClass) OverrideIsStaticImage(cb func(*PixbufAnimation) bool)

OverrideIsStaticImage sets the "is_static_image" callback function. returns whether the given animation is just a static image.

type PixbufAnimationIter 

type PixbufAnimationIter struct {
	gobject.Object
}

An opaque object representing an iterator which points to a certain position in an animation.

func PixbufAnimationIterNewFromInternalPtr 

func PixbufAnimationIterNewFromInternalPtr(ptr uintptr) *PixbufAnimationIter

func (*PixbufAnimationIter) Advance 

func (x *PixbufAnimationIter) Advance(CurrentTimeVar *glib.TimeVal) bool

Possibly advances an animation to a new frame.

Chooses the frame based on the start time passed to gdk_pixbuf_animation_get_iter().

@current_time would normally come from g_get_current_time(), and must be greater than or equal to the time passed to gdk_pixbuf_animation_get_iter(), and must increase or remain unchanged each time gdk_pixbuf_animation_iter_get_pixbuf() is called. That is, you can't go backward in time; animations only play forward.

As a shortcut, pass `NULL` for the current time and g_get_current_time() will be invoked on your behalf. So you only need to explicitly pass @current_time if you're doing something odd like playing the animation at double speed.

If this function returns `FALSE`, there's no need to update the animation display, assuming the display had been rendered prior to advancing; if `TRUE`, you need to call gdk_pixbuf_animation_iter_get_pixbuf() and update the display with the new pixbuf.

func (*PixbufAnimationIter) GetDelayTime 

func (x *PixbufAnimationIter) GetDelayTime() int32

Gets the number of milliseconds the current pixbuf should be displayed, or -1 if the current pixbuf should be displayed forever.

The `g_timeout_add()` function conveniently takes a timeout in milliseconds, so you can use a timeout to schedule the next update.

Note that some formats, like GIF, might clamp the timeout values in the image file to avoid updates that are just too quick. The minimum timeout for GIF images is currently 20 milliseconds.

func (*PixbufAnimationIter) GetPixbuf 

func (x *PixbufAnimationIter) GetPixbuf() *Pixbuf

Gets the current pixbuf which should be displayed.

The pixbuf might not be the same size as the animation itself (gdk_pixbuf_animation_get_width(), gdk_pixbuf_animation_get_height()).

This pixbuf should be displayed for gdk_pixbuf_animation_iter_get_delay_time() milliseconds.

The caller of this function does not own a reference to the returned pixbuf; the returned pixbuf will become invalid when the iterator advances to the next frame, which may happen anytime you call gdk_pixbuf_animation_iter_advance().

Copy the pixbuf to keep it (don't just add a reference), as it may get recycled as you advance the iterator.

func (*PixbufAnimationIter) GoPointer 

func (c *PixbufAnimationIter) GoPointer() uintptr

func (*PixbufAnimationIter) OnCurrentlyLoadingFrame 

func (x *PixbufAnimationIter) OnCurrentlyLoadingFrame() bool

Used to determine how to respond to the area_updated signal on #GdkPixbufLoader when loading an animation.

The `::area_updated` signal is emitted for an area of the frame currently streaming in to the loader. So if you're on the currently loading frame, you will need to redraw the screen for the updated area.

func (*PixbufAnimationIter) SetGoPointer 

func (c *PixbufAnimationIter) SetGoPointer(ptr uintptr)

type PixbufAnimationIterClass 

type PixbufAnimationIterClass struct {
	ParentClass gobject.ObjectClass
	// contains filtered or unexported fields
}

Modules supporting animations must derive a type from #GdkPixbufAnimationIter, providing suitable implementations of the virtual functions.

func (*PixbufAnimationIterClass) GetAdvance 

func (x *PixbufAnimationIterClass) GetAdvance() func(*PixbufAnimationIter, *glib.TimeVal) bool

GetAdvance gets the "advance" callback function. advances the iterator to @current_time, possibly changing the 

current frame.

func (*PixbufAnimationIterClass) GetGetDelayTime 

func (x *PixbufAnimationIterClass) GetGetDelayTime() func(*PixbufAnimationIter) int32

GetGetDelayTime gets the "get_delay_time" callback function. returns the time in milliseconds that the current frame 

should be shown.

func (*PixbufAnimationIterClass) GetGetPixbuf 

func (x *PixbufAnimationIterClass) GetGetPixbuf() func(*PixbufAnimationIter) *Pixbuf

GetGetPixbuf gets the "get_pixbuf" callback function. returns the current frame.

func (*PixbufAnimationIterClass) GetOnCurrentlyLoadingFrame 

func (x *PixbufAnimationIterClass) GetOnCurrentlyLoadingFrame() func(*PixbufAnimationIter) bool

GetOnCurrentlyLoadingFrame gets the "on_currently_loading_frame" callback function. returns whether the current frame of @iter is 

being loaded.

func (*PixbufAnimationIterClass) GoPointer 

func (x *PixbufAnimationIterClass) GoPointer() uintptr

func (*PixbufAnimationIterClass) OverrideAdvance 

func (x *PixbufAnimationIterClass) OverrideAdvance(cb func(*PixbufAnimationIter, *glib.TimeVal) bool)

OverrideAdvance sets the "advance" callback function. advances the iterator to @current_time, possibly changing the 

current frame.

func (*PixbufAnimationIterClass) OverrideGetDelayTime 

func (x *PixbufAnimationIterClass) OverrideGetDelayTime(cb func(*PixbufAnimationIter) int32)

OverrideGetDelayTime sets the "get_delay_time" callback function. returns the time in milliseconds that the current frame 

should be shown.

func (*PixbufAnimationIterClass) OverrideGetPixbuf 

func (x *PixbufAnimationIterClass) OverrideGetPixbuf(cb func(*PixbufAnimationIter) *Pixbuf)

OverrideGetPixbuf sets the "get_pixbuf" callback function. returns the current frame.

func (*PixbufAnimationIterClass) OverrideOnCurrentlyLoadingFrame 

func (x *PixbufAnimationIterClass) OverrideOnCurrentlyLoadingFrame(cb func(*PixbufAnimationIter) bool)

OverrideOnCurrentlyLoadingFrame sets the "on_currently_loading_frame" callback function. returns whether the current frame of @iter is 

being loaded.

type PixbufDestroyNotify 

type PixbufDestroyNotify func([]byte, uintptr)

A function of this type is responsible for freeing the pixel array of a pixbuf.

The gdk_pixbuf_new_from_data() function lets you pass in a pre-allocated pixel array so that a pixbuf can be created from it; in this case you will need to pass in a function of type `GdkPixbufDestroyNotify` so that the pixel data can be freed when the pixbuf is finalized.

type PixbufError 

type PixbufError int

An error code in the `GDK_PIXBUF_ERROR` domain.

Many gdk-pixbuf operations can cause errors in this domain, or in the `G_FILE_ERROR` domain. 

const (

	// An image file was broken somehow.
	GdkPixbufErrorCorruptImageValue PixbufError = 0
	// Not enough memory.
	GdkPixbufErrorInsufficientMemoryValue PixbufError = 1
	// A bad option was passed to a pixbuf save module.
	GdkPixbufErrorBadOptionValue PixbufError = 2
	// Unknown image type.
	GdkPixbufErrorUnknownTypeValue PixbufError = 3
	// Don't know how to perform the
	//  given operation on the type of image at hand.
	GdkPixbufErrorUnsupportedOperationValue PixbufError = 4
	// Generic failure code, something went wrong.
	GdkPixbufErrorFailedValue PixbufError = 5
	// Only part of the animation was loaded.
	GdkPixbufErrorIncompleteAnimationValue PixbufError = 6
)

type PixbufFormat 

type PixbufFormat struct {
	Name uintptr

	Signature *PixbufModulePattern

	Domain uintptr

	Description uintptr

	MimeTypes []string

	Extensions []string

	Flags uint32

	Disabled bool

	License uintptr
	// contains filtered or unexported fields
}

A `GdkPixbufFormat` contains information about the image format accepted by a module.

Only modules should access the fields directly, applications should use the `gdk_pixbuf_format_*` family of functions.

func PixbufGetFileInfo 

func PixbufGetFileInfo(FilenameVar string, WidthVar *int32, HeightVar *int32) *PixbufFormat

Parses an image file far enough to determine its format and size.

func PixbufGetFileInfoFinish 

func PixbufGetFileInfoFinish(AsyncResultVar gio.AsyncResult, WidthVar *int32, HeightVar *int32) (*PixbufFormat, error)

Finishes an asynchronous pixbuf parsing operation started with gdk_pixbuf_get_file_info_async().

func (*PixbufFormat) Copy 

func (x *PixbufFormat) Copy() *PixbufFormat

Creates a copy of `format`.

func (*PixbufFormat) Free 

func (x *PixbufFormat) Free()

Frees the resources allocated when copying a `GdkPixbufFormat` using gdk_pixbuf_format_copy()

func (*PixbufFormat) GetDescription 

func (x *PixbufFormat) GetDescription() string

Returns a description of the format.

func (*PixbufFormat) GetExtensions 

func (x *PixbufFormat) GetExtensions() []string

Returns the filename extensions typically used for files in the given format.

func (*PixbufFormat) GetLicense 

func (x *PixbufFormat) GetLicense() string

Returns information about the license of the image loader for the format.

The returned string should be a shorthand for a well known license, e.g. "LGPL", "GPL", "QPL", "GPL/QPL", or "other" to indicate some other license.

func (*PixbufFormat) GetMimeTypes 

func (x *PixbufFormat) GetMimeTypes() []string

Returns the mime types supported by the format.

func (*PixbufFormat) GetName 

func (x *PixbufFormat) GetName() string

Returns the name of the format.

func (*PixbufFormat) GoPointer 

func (x *PixbufFormat) GoPointer() uintptr

func (*PixbufFormat) IsDisabled 

func (x *PixbufFormat) IsDisabled() bool

Returns whether this image format is disabled.

See gdk_pixbuf_format_set_disabled().

func (*PixbufFormat) IsSaveOptionSupported 

func (x *PixbufFormat) IsSaveOptionSupported(OptionKeyVar string) bool

Returns `TRUE` if the save option specified by @option_key is supported when saving a pixbuf using the module implementing @format.

See gdk_pixbuf_save() for more information about option keys.

func (*PixbufFormat) IsScalable 

func (x *PixbufFormat) IsScalable() bool

Returns whether this image format is scalable.

If a file is in a scalable format, it is preferable to load it at the desired size, rather than loading it at the default size and scaling the resulting pixbuf to the desired size.

func (*PixbufFormat) IsWritable 

func (x *PixbufFormat) IsWritable() bool

Returns whether pixbufs can be saved in the given format.

func (*PixbufFormat) SetDisabled 

func (x *PixbufFormat) SetDisabled(DisabledVar bool)

Disables or enables an image format.

If a format is disabled, GdkPixbuf won't use the image loader for this format to load images.

Applications can use this to avoid using image loaders with an inappropriate license, see gdk_pixbuf_format_get_license().

type PixbufFormatFlags 

type PixbufFormatFlags int

Flags which allow a module to specify further details about the supported operations. 

const (

	// the module can write out images in the format.
	GdkPixbufFormatWritableValue PixbufFormatFlags = 1
	// the image format is scalable
	GdkPixbufFormatScalableValue PixbufFormatFlags = 2
	// the module is threadsafe. gdk-pixbuf
	//     ignores modules that are not marked as threadsafe. (Since 2.28).
	GdkPixbufFormatThreadsafeValue PixbufFormatFlags = 4
)

type PixbufLoader 

type PixbufLoader struct {
	gobject.Object
}

Incremental image loader.

`GdkPixbufLoader` provides a way for applications to drive the process of loading an image, by letting them send the image data directly to the loader instead of having the loader read the data from a file. Applications can use this functionality instead of `gdk_pixbuf_new_from_file()` or `gdk_pixbuf_animation_new_from_file()` when they need to parse image data in small chunks. For example, it should be used when reading an image from a (potentially) slow network connection, or when loading an extremely large file.

To use `GdkPixbufLoader` to load an image, create a new instance, and call [[email protected]] to send the data to it. When done, [[email protected]] should be called to end the stream and finalize everything.

The loader will emit three important signals throughout the process:

  • [[email protected]::size-prepared] will be emitted as soon as the image has enough information to determine the size of the image to be used. If you want to scale the image while loading it, you can call [[email protected]_size] in response to this signal.
  • [[email protected]::area-prepared] will be emitted as soon as the pixbuf of the desired has been allocated. You can obtain the `GdkPixbuf` instance by calling [[email protected]_pixbuf]. If you want to use it, simply acquire a reference to it. You can also call `gdk_pixbuf_loader_get_pixbuf()` later to get the same pixbuf.
  • [[email protected]::area-updated] will be emitted every time a region is updated. This way you can update a partially completed image. Note that you do not know anything about the completeness of an image from the updated area. For example, in an interlaced image you will need to make several passes before the image is done loading.

## Loading an animation

Loading an animation is almost as easy as loading an image. Once the first [[email protected]::area-prepared] signal has been emitted, you can call [[email protected]_animation] to get the [[email protected]] instance, and then call and [[email protected]_iter] to get a [[email protected]] to retrieve the pixbuf for the desired time stamp.

func NewPixbufLoader 

func NewPixbufLoader() *PixbufLoader

Creates a new pixbuf loader object.

func NewPixbufLoaderWithMimeType 

func NewPixbufLoaderWithMimeType(MimeTypeVar string) (*PixbufLoader, error)

Creates a new pixbuf loader object that always attempts to parse image data as if it were an image of MIME type @mime_type, instead of identifying the type automatically.

This function is useful if you want an error if the image isn't the expected MIME type; for loading image formats that can't be reliably identified by looking at the data; or if the user manually forces a specific MIME type.

The list of supported mime types depends on what image loaders are installed, but typically "image/png", "image/jpeg", "image/gif", "image/tiff" and "image/x-xpixmap" are among the supported mime types. To obtain the full list of supported mime types, call gdk_pixbuf_format_get_mime_types() on each of the #GdkPixbufFormat structs returned by gdk_pixbuf_get_formats().

func NewPixbufLoaderWithType 

func NewPixbufLoaderWithType(ImageTypeVar string) (*PixbufLoader, error)

Creates a new pixbuf loader object that always attempts to parse image data as if it were an image of type @image_type, instead of identifying the type automatically.

This function is useful if you want an error if the image isn't the expected type; for loading image formats that can't be reliably identified by looking at the data; or if the user manually forces a specific type.

The list of supported image formats depends on what image loaders are installed, but typically "png", "jpeg", "gif", "tiff" and "xpm" are among the supported formats. To obtain the full list of supported image formats, call gdk_pixbuf_format_get_name() on each of the #GdkPixbufFormat structs returned by gdk_pixbuf_get_formats().

func PixbufLoaderNewFromInternalPtr 

func PixbufLoaderNewFromInternalPtr(ptr uintptr) *PixbufLoader

func (*PixbufLoader) Close 

func (x *PixbufLoader) Close() (bool, error)

Informs a pixbuf loader that no further writes with gdk_pixbuf_loader_write() will occur, so that it can free its internal loading structures.

This function also tries to parse any data that hasn't yet been parsed; if the remaining data is partial or corrupt, an error will be returned.

If `FALSE` is returned, `error` will be set to an error from the `GDK_PIXBUF_ERROR` or `G_FILE_ERROR` domains.

If you're just cancelling a load rather than expecting it to be finished, passing `NULL` for `error` to ignore it is reasonable.

Remember that this function does not release a reference on the loader, so you will need to explicitly release any reference you hold.

func (*PixbufLoader) ConnectAreaPrepared 

func (x *PixbufLoader) ConnectAreaPrepared(cb *func(PixbufLoader)) uint32

This signal is emitted when the pixbuf loader has allocated the pixbuf in the desired size.

After this signal is emitted, applications can call gdk_pixbuf_loader_get_pixbuf() to fetch the partially-loaded pixbuf.

func (*PixbufLoader) ConnectAreaUpdated 

func (x *PixbufLoader) ConnectAreaUpdated(cb *func(PixbufLoader, int32, int32, int32, int32)) uint32

This signal is emitted when a significant area of the image being loaded has been updated.

Normally it means that a complete scanline has been read in, but it could be a different area as well.

Applications can use this signal to know when to repaint areas of an image that is being loaded.

func (*PixbufLoader) ConnectClosed 

func (x *PixbufLoader) ConnectClosed(cb *func(PixbufLoader)) uint32

This signal is emitted when gdk_pixbuf_loader_close() is called.

It can be used by different parts of an application to receive notification when an image loader is closed by the code that drives it.

func (*PixbufLoader) ConnectSizePrepared 

func (x *PixbufLoader) ConnectSizePrepared(cb *func(PixbufLoader, int32, int32)) uint32

This signal is emitted when the pixbuf loader has been fed the initial amount of data that is required to figure out the size of the image that it will create.

Applications can call gdk_pixbuf_loader_set_size() in response to this signal to set the desired size to which the image should be scaled.

func (*PixbufLoader) GetAnimation 

func (x *PixbufLoader) GetAnimation() *PixbufAnimation

Queries the #GdkPixbufAnimation that a pixbuf loader is currently creating.

In general it only makes sense to call this function after the [[email protected]::area-prepared] signal has been emitted by the loader.

If the loader doesn't have enough bytes yet, and hasn't emitted the `area-prepared` signal, this function will return `NULL`.

func (*PixbufLoader) GetFormat 

func (x *PixbufLoader) GetFormat() *PixbufFormat

Obtains the available information about the format of the currently loading image file.

func (*PixbufLoader) GetPixbuf 

func (x *PixbufLoader) GetPixbuf() *Pixbuf

Queries the #GdkPixbuf that a pixbuf loader is currently creating.

In general it only makes sense to call this function after the [[email protected]::area-prepared] signal has been emitted by the loader; this means that enough data has been read to know the size of the image that will be allocated.

If the loader has not received enough data via gdk_pixbuf_loader_write(), then this function returns `NULL`.

The returned pixbuf will be the same in all future calls to the loader, so if you want to keep using it, you should acquire a reference to it.

Additionally, if the loader is an animation, it will return the "static image" of the animation (see gdk_pixbuf_animation_get_static_image()).

func (*PixbufLoader) GoPointer 

func (c *PixbufLoader) GoPointer() uintptr

func (*PixbufLoader) SetGoPointer 

func (c *PixbufLoader) SetGoPointer(ptr uintptr)

func (*PixbufLoader) SetSize 

func (x *PixbufLoader) SetSize(WidthVar int32, HeightVar int32)

Causes the image to be scaled while it is loaded.

The desired image size can be determined relative to the original size of the image by calling gdk_pixbuf_loader_set_size() from a signal handler for the ::size-prepared signal.

Attempts to set the desired image size are ignored after the emission of the ::size-prepared signal.

func (*PixbufLoader) Write 

func (x *PixbufLoader) Write(BufVar []byte, CountVar uint) (bool, error)

Parses the next `count` bytes in the given image buffer.

func (*PixbufLoader) WriteBytes 

func (x *PixbufLoader) WriteBytes(BufferVar *glib.Bytes) (bool, error)

Parses the next contents of the given image buffer.

type PixbufLoaderClass 

type PixbufLoaderClass struct {
	ParentClass gobject.ObjectClass
	// contains filtered or unexported fields
}

func (*PixbufLoaderClass) GetAreaPrepared 

func (x *PixbufLoaderClass) GetAreaPrepared() func(*PixbufLoader)

GetAreaPrepared gets the "area_prepared" callback function.

func (*PixbufLoaderClass) GetAreaUpdated 

func (x *PixbufLoaderClass) GetAreaUpdated() func(*PixbufLoader, int32, int32, int32, int32)

GetAreaUpdated gets the "area_updated" callback function.

func (*PixbufLoaderClass) GetClosed 

func (x *PixbufLoaderClass) GetClosed() func(*PixbufLoader)

GetClosed gets the "closed" callback function.

func (*PixbufLoaderClass) GetSizePrepared 

func (x *PixbufLoaderClass) GetSizePrepared() func(*PixbufLoader, int32, int32)

GetSizePrepared gets the "size_prepared" callback function.

func (*PixbufLoaderClass) GoPointer 

func (x *PixbufLoaderClass) GoPointer() uintptr

func (*PixbufLoaderClass) OverrideAreaPrepared 

func (x *PixbufLoaderClass) OverrideAreaPrepared(cb func(*PixbufLoader))

OverrideAreaPrepared sets the "area_prepared" callback function.

func (*PixbufLoaderClass) OverrideAreaUpdated 

func (x *PixbufLoaderClass) OverrideAreaUpdated(cb func(*PixbufLoader, int32, int32, int32, int32))

OverrideAreaUpdated sets the "area_updated" callback function.

func (*PixbufLoaderClass) OverrideClosed 

func (x *PixbufLoaderClass) OverrideClosed(cb func(*PixbufLoader))

OverrideClosed sets the "closed" callback function.

func (*PixbufLoaderClass) OverrideSizePrepared 

func (x *PixbufLoaderClass) OverrideSizePrepared(cb func(*PixbufLoader, int32, int32))

OverrideSizePrepared sets the "size_prepared" callback function.

type PixbufModule 

type PixbufModule struct {
	ModuleName uintptr

	ModulePath uintptr

	Module *gmodule.Module

	Info *PixbufFormat

	Load PixbufModuleLoadFunc

	LoadXpmData PixbufModuleLoadXpmDataFunc

	BeginLoad PixbufModuleBeginLoadFunc

	StopLoad PixbufModuleStopLoadFunc

	LoadIncrement PixbufModuleIncrementLoadFunc

	LoadAnimation PixbufModuleLoadAnimationFunc

	Save PixbufModuleSaveFunc

	SaveToCallback PixbufModuleSaveCallbackFunc

	IsSaveOptionSupported PixbufModuleSaveOptionSupportedFunc
	// contains filtered or unexported fields
}

A `GdkPixbufModule` contains the necessary functions to load and save images in a certain file format.

If `GdkPixbuf` has been compiled with `GModule` support, it can be extended by modules which can load (and perhaps also save) new image and animation formats.

## Implementing modules

The `GdkPixbuf` interfaces needed for implementing modules are contained in `gdk-pixbuf-io.h` (and `gdk-pixbuf-animation.h` if the module supports animations). They are not covered by the same stability guarantees as the regular GdkPixbuf API. To underline this fact, they are protected by the `GDK_PIXBUF_ENABLE_BACKEND` pre-processor symbol.

Each loadable module must contain a `GdkPixbufModuleFillVtableFunc` function named `fill_vtable`, which will get called when the module is loaded and must set the function pointers of the `GdkPixbufModule`.

In order to make format-checking work before actually loading the modules (which may require calling `dlopen` to load image libraries), modules export their signatures (and other information) via the `fill_info` function. An external utility, `gdk-pixbuf-query-loaders`, uses this to create a text file containing a list of all available loaders and their signatures. This file is then read at runtime by `GdkPixbuf` to obtain the list of available loaders and their signatures.

Modules may only implement a subset of the functionality available via `GdkPixbufModule`. If a particular functionality is not implemented, the `fill_vtable` function will simply not set the corresponding function pointers of the `GdkPixbufModule` structure. If a module supports incremental loading (i.e. provides `begin_load`, `stop_load` and `load_increment`), it doesn't have to implement `load`, since `GdkPixbuf` can supply a generic `load` implementation wrapping the incremental loading.

## Installing modules

Installing a module is a two-step process:

  • copy the module file(s) to the loader directory (normally `$libdir/gdk-pixbuf-2.0/$version/loaders`, unless overridden by the environment variable `GDK_PIXBUF_MODULEDIR`)
  • call `gdk-pixbuf-query-loaders` to update the module file (normally `$libdir/gdk-pixbuf-2.0/$version/loaders.cache`, unless overridden by the environment variable `GDK_PIXBUF_MODULE_FILE`)

func (*PixbufModule) GetReserved1 

func (x *PixbufModule) GetReserved1() func()

GetReserved1 gets the "_reserved1" callback function.

func (*PixbufModule) GetReserved2 

func (x *PixbufModule) GetReserved2() func()

GetReserved2 gets the "_reserved2" callback function.

func (*PixbufModule) GetReserved3 

func (x *PixbufModule) GetReserved3() func()

GetReserved3 gets the "_reserved3" callback function.

func (*PixbufModule) GetReserved4 

func (x *PixbufModule) GetReserved4() func()

GetReserved4 gets the "_reserved4" callback function.

func (*PixbufModule) GoPointer 

func (x *PixbufModule) GoPointer() uintptr

func (*PixbufModule) OverrideReserved1 

func (x *PixbufModule) OverrideReserved1(cb func())

OverrideReserved1 sets the "_reserved1" callback function.

func (*PixbufModule) OverrideReserved2 

func (x *PixbufModule) OverrideReserved2(cb func())

OverrideReserved2 sets the "_reserved2" callback function.

func (*PixbufModule) OverrideReserved3 

func (x *PixbufModule) OverrideReserved3(cb func())

OverrideReserved3 sets the "_reserved3" callback function.

func (*PixbufModule) OverrideReserved4 

func (x *PixbufModule) OverrideReserved4(cb func())

OverrideReserved4 sets the "_reserved4" callback function.

type PixbufModuleBeginLoadFunc 

type PixbufModuleBeginLoadFunc func(uintptr, uintptr, uintptr, uintptr, **glib.Error) uintptr

Sets up the image loading state.

The image loader is responsible for storing the given function pointers and user data, and call them when needed.

The image loader should set up an internal state object, and return it from this function; the state object will then be updated from the [[email protected]] callback, and will be freed by [[email protected]] callback.

type PixbufModuleFillInfoFunc 

type PixbufModuleFillInfoFunc func(*PixbufFormat)

Defines the type of the function used to fill a #GdkPixbufFormat structure with information about a module.

type PixbufModuleFillVtableFunc 

type PixbufModuleFillVtableFunc func(*PixbufModule)

Defines the type of the function used to set the vtable of a #GdkPixbufModule when it is loaded.

type PixbufModuleIncrementLoadFunc 

type PixbufModuleIncrementLoadFunc func(uintptr, []byte, uint32, **glib.Error) bool

Incrementally loads a buffer into the image data.

type PixbufModuleLoadAnimationFunc 

type PixbufModuleLoadAnimationFunc func(uintptr, **glib.Error) uintptr

Loads a file from a standard C file stream into a new `GdkPixbufAnimation`.

In case of error, this function should return `NULL` and set the `error` argument.

type PixbufModuleLoadFunc 

type PixbufModuleLoadFunc func(uintptr, **glib.Error) uintptr

Loads a file from a standard C file stream into a new `GdkPixbuf`.

In case of error, this function should return `NULL` and set the `error` argument.

type PixbufModuleLoadXpmDataFunc 

type PixbufModuleLoadXpmDataFunc func([]string) uintptr

Loads XPM data into a new `GdkPixbuf`.

type PixbufModulePattern 

type PixbufModulePattern struct {
	Prefix uintptr

	Mask uintptr

	Relevance int32
	// contains filtered or unexported fields
}

The signature prefix for a module.

The signature of a module is a set of prefixes. Prefixes are encoded as pairs of ordinary strings, where the second string, called the mask, if not `NULL`, must be of the same length as the first one and may contain ' ', '!', 'x', 'z', and 'n' to indicate bytes that must be matched, not matched, "don't-care"-bytes, zeros and non-zeros, respectively.

Each prefix has an associated integer that describes the relevance of the prefix, with 0 meaning a mismatch and 100 a "perfect match".

Starting with gdk-pixbuf 2.8, the first byte of the mask may be '*', indicating an unanchored pattern that matches not only at the beginning, but also in the middle. Versions prior to 2.8 will interpret the '*' like an 'x'.

The signature of a module is stored as an array of `GdkPixbufModulePatterns`. The array is terminated by a pattern where the `prefix` is `NULL`.

```c 

GdkPixbufModulePattern *signature[] = {
  { "abcdx", " !x z", 100 },
  { "bla", NULL,  90 },
  { NULL, NULL, 0 }
};

```

In the example above, the signature matches e.g. "auud\0" with relevance 100, and "blau" with relevance 90.

func (*PixbufModulePattern) GoPointer 

func (x *PixbufModulePattern) GoPointer() uintptr

type PixbufModulePreparedFunc 

type PixbufModulePreparedFunc func(uintptr, uintptr, uintptr)

Defines the type of the function that gets called once the initial setup of @pixbuf is done.

#GdkPixbufLoader uses a function of this type to emit the "<link linkend="GdkPixbufLoader-area-prepared">area_prepared</link>" signal.

type PixbufModuleSaveCallbackFunc 

type PixbufModuleSaveCallbackFunc func(uintptr, uintptr, uintptr, []string, []string, **glib.Error) bool

Saves a `GdkPixbuf` by calling the provided function.

The optional `option_keys` and `option_values` arrays contain the keys and values (in the same order) for attributes to be saved alongside the image data.

type PixbufModuleSaveFunc 

type PixbufModuleSaveFunc func(uintptr, uintptr, []string, []string, **glib.Error) bool

Saves a `GdkPixbuf` into a standard C file stream.

The optional `param_keys` and `param_values` arrays contain the keys and values (in the same order) for attributes to be saved alongside the image data.

type PixbufModuleSaveOptionSupportedFunc 

type PixbufModuleSaveOptionSupportedFunc func(string) bool

Checks whether the given `option_key` is supported when saving.

type PixbufModuleSizeFunc 

type PixbufModuleSizeFunc func(int32, int32, uintptr)

Defines the type of the function that gets called once the size of the loaded image is known.

The function is expected to set @width and @height to the desired size to which the image should be scaled. If a module has no efficient way to achieve the desired scaling during the loading of the image, it may either ignore the size request, or only approximate it - gdk-pixbuf will then perform the required scaling on the completely loaded image.

If the function sets @width or @height to zero, the module should interpret this as a hint that it will be closed soon and shouldn't allocate further resources. This convention is used to implement gdk_pixbuf_get_file_info() efficiently.

type PixbufModuleStopLoadFunc 

type PixbufModuleStopLoadFunc func(uintptr, **glib.Error) bool

Finalizes the image loading state.

This function is called on success and error states.

type PixbufModuleUpdatedFunc 

type PixbufModuleUpdatedFunc func(uintptr, int32, int32, int32, int32, uintptr)

Defines the type of the function that gets called every time a region of @pixbuf is updated.

#GdkPixbufLoader uses a function of this type to emit the "<link linkend="GdkPixbufLoader-area-updated">area_updated</link>" signal.

type PixbufNonAnim 

type PixbufNonAnim struct {
	PixbufAnimation
}

func NewPixbufNonAnim 

func NewPixbufNonAnim(PixbufVar *Pixbuf) *PixbufNonAnim

func PixbufNonAnimNewFromInternalPtr 

func PixbufNonAnimNewFromInternalPtr(ptr uintptr) *PixbufNonAnim

func (*PixbufNonAnim) GoPointer 

func (c *PixbufNonAnim) GoPointer() uintptr

func (*PixbufNonAnim) SetGoPointer 

func (c *PixbufNonAnim) SetGoPointer(ptr uintptr)

type PixbufRotation 

type PixbufRotation int

The possible rotations which can be passed to gdk_pixbuf_rotate_simple().

To make them easier to use, their numerical values are the actual degrees. 

const (

	// No rotation.
	GdkPixbufRotateNoneValue PixbufRotation = 0
	// Rotate by 90 degrees.
	GdkPixbufRotateCounterclockwiseValue PixbufRotation = 90
	// Rotate by 180 degrees.
	GdkPixbufRotateUpsidedownValue PixbufRotation = 180
	// Rotate by 270 degrees.
	GdkPixbufRotateClockwiseValue PixbufRotation = 270
)

type PixbufSaveFunc 

type PixbufSaveFunc func([]byte, uint, **glib.Error, uintptr) bool

Save functions used by [[email protected]_to_callback].

This function is called once for each block of bytes that is "written" by `gdk_pixbuf_save_to_callback()`.

If successful it should return `TRUE`; if an error occurs it should set `error` and return `FALSE`, in which case `gdk_pixbuf_save_to_callback()` will fail with the same error.

type PixbufSimpleAnim 

type PixbufSimpleAnim struct {
	PixbufAnimation
}

An opaque struct representing a simple animation.

func NewPixbufSimpleAnim 

func NewPixbufSimpleAnim(WidthVar int32, HeightVar int32, RateVar float32) *PixbufSimpleAnim

Creates a new, empty animation.

func PixbufSimpleAnimNewFromInternalPtr 

func PixbufSimpleAnimNewFromInternalPtr(ptr uintptr) *PixbufSimpleAnim

func (*PixbufSimpleAnim) AddFrame 

func (x *PixbufSimpleAnim) AddFrame(PixbufVar *Pixbuf)

Adds a new frame to @animation. The @pixbuf must have the dimensions specified when the animation was constructed.

func (*PixbufSimpleAnim) GetLoop 

func (x *PixbufSimpleAnim) GetLoop() bool

Gets whether @animation should loop indefinitely when it reaches the end.

func (*PixbufSimpleAnim) GetPropertyLoop 

func (x *PixbufSimpleAnim) GetPropertyLoop() bool

GetPropertyLoop gets the "loop" property. Whether the animation should loop when it reaches the end.

func (*PixbufSimpleAnim) GoPointer 

func (c *PixbufSimpleAnim) GoPointer() uintptr

func (*PixbufSimpleAnim) SetGoPointer 

func (c *PixbufSimpleAnim) SetGoPointer(ptr uintptr)

func (*PixbufSimpleAnim) SetLoop 

func (x *PixbufSimpleAnim) SetLoop(LoopVar bool)

Sets whether @animation should loop indefinitely when it reaches the end.

func (*PixbufSimpleAnim) SetPropertyLoop 

func (x *PixbufSimpleAnim) SetPropertyLoop(value bool)

SetPropertyLoop sets the "loop" property. Whether the animation should loop when it reaches the end.

type PixbufSimpleAnimClass 

type PixbufSimpleAnimClass struct {
	// contains filtered or unexported fields
}

func (*PixbufSimpleAnimClass) GoPointer 

func (x *PixbufSimpleAnimClass) GoPointer() uintptr

type PixbufSimpleAnimIter 

type PixbufSimpleAnimIter struct {
	PixbufAnimationIter
}

func PixbufSimpleAnimIterNewFromInternalPtr 

func PixbufSimpleAnimIterNewFromInternalPtr(ptr uintptr) *PixbufSimpleAnimIter

func (*PixbufSimpleAnimIter) GoPointer 

func (c *PixbufSimpleAnimIter) GoPointer() uintptr

func (*PixbufSimpleAnimIter) SetGoPointer 

func (c *PixbufSimpleAnimIter) SetGoPointer(ptr uintptr)

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