gtk-0.12.4: Binding to the Gtk+ graphical user interface library.

Portabilityportable (depends on GHC)
Stabilityprovisional
Maintainergtk2hs-users@lists.sourceforge.net
Safe HaskellNone

Graphics.UI.Gtk.Gdk.PixbufAnimation

Contents

Description

 

Synopsis

Class Hierarchy

Types

Constructors

pixbufAnimationNewFromFileSource

Arguments

:: FilePath

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

-> IO PixbufAnimation

A newly-created animation

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 PixbufError and GFileError domains.

Any of several error conditions may occur: 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.

  • If an error occurs, the function will throw an exception that can be caught using e.g. catchGErrorJust and one of the error codes in PixbufError or GFileError

pixbufSimpleAnimNewSource

Arguments

:: Int

the width of the animation

-> Int

the height of the animation

-> Float

the speed of the animation, in frames per second

-> IO PixbufSimpleAnim

a newly allocated PixbufSimpleAnim

Creates a new, empty animation.

  • Available since Gtk+ version 2.8

Methods

pixbufAnimationGetWidthSource

Arguments

:: PixbufAnimation

An animation.

-> IO Int

Width of the bounding box of the animation.

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

pixbufAnimationGetHeightSource

Arguments

:: PixbufAnimation

An animation.

-> IO Int

Height of the bounding box of the animation.

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

pixbufAnimationGetIterSource

Arguments

:: PixbufAnimation

a PixbufAnimation

-> Maybe GTimeVal

time when the animation starts playing

-> IO PixbufAnimationIter

an iterator to move over the animation

Get an iterator for displaying an animation. The iterator provides the frames that should be displayed at a given time. The start time would normally come from gGetCurrentTime, and marks the beginning of animation playback. After creating an iterator, you should immediately display the pixbuf returned by pixbufAnimationIterGetPixbuf. Then, you should install a timeout (with timeoutAdd) or by some other mechanism ensure that you'll update the image after pixbufAnimationIterGetDelayTime 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 Nothing, the result of gGetCurrentTime will be used automatically.

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

If you're using PixbufLoader, in addition to updating the image after the delay time, you should also update it whenever you receive the area_updated signal and pixbufAnimationIterOnCurrentlyLoadingFrame 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.

pixbufAnimationIsStaticImageSource

Arguments

:: PixbufAnimation 
-> IO Bool

(!(0)) if the animation was really just an image

If you load a file with pixbufAnimationNewFromFile and it turns out to be a plain, unanimated image, then this function will return True. Use pixbufAnimationGetStaticImage to retrieve the image.

pixbufAnimationGetStaticImageSource

Arguments

:: PixbufAnimation 
-> IO (Maybe Pixbuf)

unanimated image representing 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 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 Nothing.

pixbufAnimationIterAdvanceSource

Arguments

:: PixbufAnimationIter

A PixbufAnimationIter

-> Maybe GTimeVal

current time

-> IO Bool

True if the image may need updating

Possibly advances an animation to a new frame. Chooses the frame based on the start time passed to pixbufAnimationGetIter.

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

As a shortcut, pass Nothing for the current time and gGetCurrentTime 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 animationIterGetPixbuf and update the display with the new pixbuf.

pixbufAnimationIterGetDelayTimeSource

Arguments

:: PixbufAnimationIter

an animation iterator

-> IO Int

delay time in milliseconds (thousandths of a second)

Gets the number of milliseconds the current pixbuf should be displayed, or -1 if the current pixbuf should be displayed forever. timeoutAdd conveniently takes a timeout in milliseconds, so you can use a timeout to schedule the next update.

pixbufAnimationIterOnCurrentlyLoadingFrameSource

Arguments

:: PixbufAnimationIter 
-> IO Bool

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

Used to determine how to respond to the area_updated signal on PixbufLoader 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.

pixbufAnimationIterGetPixbufSource

Arguments

:: PixbufAnimationIter

an animation iterator

-> IO Pixbuf

the pixbuf to be displayed

Gets the current pixbuf which should be displayed; the pixbuf will be the same size as the animation itself (pixbufAnimationGetWidth, pixbufAnimationGetHeight). This pixbuf should be displayed for pixbufAnimationIterGetDelayTime 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 pixbufAnimationIterAdvance. Copy the pixbuf to keep it (don't just add a reference), as it may get recycled as you advance the iterator.

pixbufSimpleAnimAddFrameSource

Arguments

:: PixbufSimpleAnim

a PixbufSimpleAnim

-> Pixbuf

the pixbuf to add

-> IO () 

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

  • Available since Gtk+ version 2.8

pixbufSimpleAnimSetLoopSource

Arguments

:: PixbufSimpleAnim

a PixbufSimpleAnim

-> Bool

whether to loop the animation

-> IO () 

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

  • Available since Gtk+ version 2.18

pixbufSimpleAnimGetLoopSource

Arguments

:: PixbufSimpleAnim

a PixbufSimpleAnim

-> IO Bool

True if the animation loops forever, False otherwise

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

  • Available since Gtk+ version 2.18