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Animations

Animations — Animated images.

Properties

gboolean loop Read / Write

Object Hierarchy

    GObject
    ├── GdkPixbufAnimation
       ╰── GdkPixbufSimpleAnim
    ╰── GdkPixbufAnimationIter

Includes

#include <gdk-pixbuf/gdk-pixbuf.h>

Description

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.

Functions

gdk_pixbuf_animation_new_from_file ()

GdkPixbufAnimation *
gdk_pixbuf_animation_new_from_file (const char *filename,
                                    GError **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.

Parameters

filename

Name of file to load, in the GLib file name encoding

 

error

return location for error

 

Returns

A newly-created animation with a reference count of 1, or NULL if any of several error conditions ocurred: the file could not be opened, there was no loader for the file's format, there was not enough memory to allocate the image buffer, or the image file contained invalid data.


gdk_pixbuf_animation_new_from_resource ()

GdkPixbufAnimation *
gdk_pixbuf_animation_new_from_resource
                               (const char *resource_path,
                                GError **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.

Parameters

resource_path

the path of the resource file

 

error

Return location for an error

 

Returns

A newly-created animation, or NULL if any of several error conditions occurred: the file could not be opened, the image format is not supported, there was not enough memory to allocate the image buffer, the stream contained invalid data, or the operation was cancelled.

Since: 2.28


gdk_pixbuf_animation_new_from_stream ()

GdkPixbufAnimation *
gdk_pixbuf_animation_new_from_stream (GInputStream *stream,
                                      GCancellable *cancellable,
                                      GError **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.

Parameters

stream

a GInputStream to load the pixbuf from

 

cancellable

optional GCancellable object, NULL to ignore.

[allow-none]

error

Return location for an error

 

Returns

A newly-created pixbuf, or NULL if any of several error conditions occurred: the file could not be opened, the image format is not supported, there was not enough memory to allocate the image buffer, the stream contained invalid data, or the operation was cancelled.

Since: 2.28


gdk_pixbuf_animation_new_from_stream_async ()

void
gdk_pixbuf_animation_new_from_stream_async
                               (GInputStream *stream,
                                GCancellable *cancellable,
                                GAsyncReadyCallback callback,
                                gpointer user_data);

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.

Parameters

stream

a GInputStream from which to load the animation

 

cancellable

optional GCancellable object, NULL to ignore.

[allow-none]

callback

a GAsyncReadyCallback to call when the pixbuf is loaded

 

user_data

the data to pass to the callback function

 

Since: 2.28


gdk_pixbuf_animation_new_from_stream_finish ()

GdkPixbufAnimation *
gdk_pixbuf_animation_new_from_stream_finish
                               (GAsyncResult *async_result,
                                GError **error);

Finishes an asynchronous pixbuf animation creation operation started with gdk_pixbuf_animation_new_from_stream_async().

Parameters

async_result

a GAsyncResult

 

error

a GError, or NULL

 

Returns

a GdkPixbufAnimation or NULL on error. Free the returned object with g_object_unref().

Since: 2.28


gdk_pixbuf_animation_ref ()

GdkPixbufAnimation *
gdk_pixbuf_animation_ref (GdkPixbufAnimation *animation);

gdk_pixbuf_animation_ref has been deprecated since version 2.0 and should not be used in newly-written code.

Use g_object_ref().

Adds a reference to an animation.

[skip]

Parameters

animation

An animation.

 

Returns

The same as the animation argument.


gdk_pixbuf_animation_unref ()

void
gdk_pixbuf_animation_unref (GdkPixbufAnimation *animation);

gdk_pixbuf_animation_unref has been deprecated since version 2.0 and should not be used in newly-written code.

Use g_object_unref().

Removes a reference from an animation.

[skip]

Parameters

animation

An animation.

 

gdk_pixbuf_animation_get_width ()

int
gdk_pixbuf_animation_get_width (GdkPixbufAnimation *animation);

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

Parameters

animation

An animation.

 

Returns

Width of the bounding box of the animation.


gdk_pixbuf_animation_get_height ()

int
gdk_pixbuf_animation_get_height (GdkPixbufAnimation *animation);

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

Parameters

animation

An animation.

 

Returns

Height of the bounding box of the animation.


gdk_pixbuf_animation_get_iter ()

GdkPixbufAnimationIter *
gdk_pixbuf_animation_get_iter (GdkPixbufAnimation *animation,
                               const GTimeVal *start_time);

Get an iterator for displaying an animation. The iterator provides the frames that should be displayed at a given time. It should be freed after use with g_object_unref().

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."

Parameters

animation

a GdkPixbufAnimation

 

start_time

time when the animation starts playing.

[allow-none]

Returns

an iterator to move over the animation.

[transfer full]


gdk_pixbuf_animation_is_static_image ()

gboolean
gdk_pixbuf_animation_is_static_image (GdkPixbufAnimation *animation);

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.

Parameters

animation

a GdkPixbufAnimation

 

Returns

TRUE if the "animation" was really just an image


gdk_pixbuf_animation_get_static_image ()

GdkPixbuf *
gdk_pixbuf_animation_get_static_image (GdkPixbufAnimation *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 thing to display as a static unanimated image, which might be the first frame, or something more sophisticated. If an animation hasn't loaded any frames yet, this function will return NULL.

Parameters

animation

a GdkPixbufAnimation

 

Returns

unanimated image representing the animation.

[transfer none]


gdk_pixbuf_animation_iter_advance ()

gboolean
gdk_pixbuf_animation_iter_advance (GdkPixbufAnimationIter *iter,
                                   const GTimeVal *current_time);

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.

Parameters

iter

a GdkPixbufAnimationIter

 

current_time

current time.

[allow-none]

Returns

TRUE if the image may need updating


gdk_pixbuf_animation_iter_get_delay_time ()

int
gdk_pixbuf_animation_iter_get_delay_time
                               (GdkPixbufAnimationIter *iter);

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

Parameters

iter

an animation iterator

 

Returns

delay time in milliseconds (thousandths of a second)


gdk_pixbuf_animation_iter_on_currently_loading_frame ()

gboolean
gdk_pixbuf_animation_iter_on_currently_loading_frame
                               (GdkPixbufAnimationIter *iter);

Used to determine how to respond to the area_updated signal on GdkPixbufLoader when loading an animation. area_updated is emitted for an area of the frame currently streaming in to the loader. So if you're on the currently loading frame, you need to redraw the screen for the updated area.

Parameters

Returns

TRUE if the frame we're on is partially loaded, or the last frame


gdk_pixbuf_animation_iter_get_pixbuf ()

GdkPixbuf *
gdk_pixbuf_animation_iter_get_pixbuf (GdkPixbufAnimationIter *iter);

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.

Parameters

iter

an animation iterator

 

Returns

the pixbuf to be displayed.

[transfer none]


gdk_pixbuf_simple_anim_new ()

GdkPixbufSimpleAnim *
gdk_pixbuf_simple_anim_new (gint width,
                            gint height,
                            gfloat rate);

Creates a new, empty animation.

Parameters

width

the width of the animation

 

height

the height of the animation

 

rate

the speed of the animation, in frames per second

 

Returns

a newly allocated GdkPixbufSimpleAnim

Since: 2.8


gdk_pixbuf_simple_anim_add_frame ()

void
gdk_pixbuf_simple_anim_add_frame (GdkPixbufSimpleAnim *animation,
                                  GdkPixbuf *pixbuf);

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

Parameters

animation

a GdkPixbufSimpleAnim

 

pixbuf

the pixbuf to add

 

Since: 2.8


gdk_pixbuf_simple_anim_set_loop ()

void
gdk_pixbuf_simple_anim_set_loop (GdkPixbufSimpleAnim *animation,
                                 gboolean loop);

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

Parameters

animation

a GdkPixbufSimpleAnim

 

loop

whether to loop the animation

 

Since: 2.18


gdk_pixbuf_simple_anim_get_loop ()

gboolean
gdk_pixbuf_simple_anim_get_loop (GdkPixbufSimpleAnim *animation);

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

Parameters

animation

a GdkPixbufSimpleAnim

 

Returns

TRUE if the animation loops forever, FALSE otherwise

Since: 2.18

Types and Values

struct GdkPixbufAnimation

struct GdkPixbufAnimation;

An opaque struct representing an animation.


struct GdkPixbufAnimationIter

struct GdkPixbufAnimationIter;

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


GdkPixbufSimpleAnim

typedef struct _GdkPixbufSimpleAnim GdkPixbufSimpleAnim;

An opaque struct representing a simple animation.

Property Details

The “loop” property

  “loop”                     gboolean

Whether the animation should loop when it reaches the end.

Flags: Read / Write

Default value: FALSE

Since: 2.18

See Also

GdkPixbufLoader.

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