class GdkPixbuf::PixbufAnimation

Overview

An opaque object representing an animation.

The Gdk::PixBuf 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 Gdk::Pixbuf what should be displayed at a given point in time.

Direct Known Subclasses

Defined in:

lib/gi-crystal/src/auto/gdk_pixbuf-2.0/pixbuf_animation.cr

Constructors

Class Method Summary

Instance Method Summary

Instance methods inherited from class GObject::Object

bind_property(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags) : GObject::Binding bind_property, bind_property_full(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags, transform_to : GObject::Closure, transform_from : GObject::Closure) : GObject::Binding bind_property_full, data(key : String) : Pointer(Void)? data, finalize finalize, freeze_notify : Nil freeze_notify, getv(names : Enumerable(String), values : Enumerable(_)) : Nil getv, notify(property_name : String) : Nil notify, notify_by_pspec(pspec : GObject::ParamSpec) : Nil notify_by_pspec, notify_signal notify_signal, property(property_name : String, value : _) : Nil property, qdata(quark : UInt32) : Pointer(Void)? qdata, ref_count : UInt32 ref_count, run_dispose : Nil run_dispose, set_data(key : String, data : Pointer(Void)?) : Nil set_data, set_property(property_name : String, value : _) : Nil set_property, steal_data(key : String) : Pointer(Void)? steal_data, steal_qdata(quark : UInt32) : Pointer(Void)? steal_qdata, thaw_notify : Nil thaw_notify, to_unsafe : Pointer(Void) to_unsafe, watch_closure(closure : GObject::Closure) : Nil watch_closure

Constructor methods inherited from class GObject::Object

cast(obj : GObject::Object) : self cast, cast?(obj : GObject::Object) : self? cast?, new(pointer : Pointer(Void), transfer : GICrystal::Transfer)
new new, newv(object_type : UInt64, parameters : Enumerable(GObject::Parameter)) : self newv

Class methods inherited from class GObject::Object

compat_control(what : UInt64, data : Pointer(Void)?) : UInt64 compat_control, g_type : UInt64 g_type, interface_find_property(g_iface : GObject::TypeInterface, property_name : String) : GObject::ParamSpec interface_find_property, interface_list_properties(g_iface : GObject::TypeInterface) : Enumerable(GObject::ParamSpec) interface_list_properties

Constructor Detail

def self.new #

Initialize a new PixbufAnimation.


def self.new_from_file(filename : String) : self? #

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.


def self.new_from_resource(resource_path : String) : self? #

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.


def self.new_from_stream(stream : Gio::InputStream, cancellable : Gio::Cancellable?) : self? #

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.


def self.new_from_stream_finish(async_result : Gio::AsyncResult) : self? #

Finishes an asynchronous pixbuf animation creation operation started with Gdk::Pixbuf::PixbufAnimation#new_from_stream_async.


Class Method Detail

def self.g_type : UInt64 #

Returns the type id (GType) registered in GLib type system.


def self.new_from_stream_async(stream : Gio::InputStream, cancellable : Gio::Cancellable?, callback : Gio::AsyncReadyCallback?, user_data : Pointer(Void)?) : Nil #

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.


Instance Method Detail

def height : Int32 #

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


def is_static_image : 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.


def iter(start_time : GLib::TimeVal?) : GdkPixbuf::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 #Gdk::PixbufLoader, 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".


def static_image : GdkPixbuf::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.


def width : Int32 #

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