GI.GdkPixbuf.Objects.PixbufAnimationIter

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

Exported types

newtype PixbufAnimationIter

Memory-managed wrapper type.

Constructors

PixbufAnimationIter (ManagedPtr PixbufAnimationIter)

Instances

Eq PixbufAnimationIter

Defined in GI.GdkPixbuf.Objects.PixbufAnimationIter

Methods

(==) :: PixbufAnimationIter -> PixbufAnimationIter -> Bool

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

IsGValue PixbufAnimationIter

Convert PixbufAnimationIter to and from GValue with toGValue and fromGValue.

Defined in GI.GdkPixbuf.Objects.PixbufAnimationIter

Methods

toGValue :: PixbufAnimationIter -> IO GValue

fromGValue :: GValue -> IO PixbufAnimationIter

GObject PixbufAnimationIter

Defined in GI.GdkPixbuf.Objects.PixbufAnimationIter

Methods

gobjectType :: IO GType

HasParentTypes PixbufAnimationIter

Defined in GI.GdkPixbuf.Objects.PixbufAnimationIter

type ParentTypes PixbufAnimationIter

Defined in GI.GdkPixbuf.Objects.PixbufAnimationIter

type ParentTypes PixbufAnimationIter = '[Object]

class (GObject o, IsDescendantOf PixbufAnimationIter o) => IsPixbufAnimationIter o

Type class for types which can be safely cast to PixbufAnimationIter, for instance with toPixbufAnimationIter.

Instances

(GObject o, IsDescendantOf PixbufAnimationIter o) => IsPixbufAnimationIter o

Defined in GI.GdkPixbuf.Objects.PixbufAnimationIter

toPixbufAnimationIter :: (MonadIO m, IsPixbufAnimationIter o) => o -> m PixbufAnimationIter

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

noPixbufAnimationIter :: Maybe PixbufAnimationIter

A convenience alias for Nothing :: Maybe PixbufAnimationIter.

Methods

Overloaded methods

advance

pixbufAnimationIterAdvance

Arguments

:: (HasCallStack, MonadIO m, IsPixbufAnimationIter a)

=> a

iter: a PixbufAnimationIter

-> Maybe TimeVal

currentTime: current time

-> m Bool

Returns: 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.

currentTime would normally come from getCurrentTime, 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 getCurrentTime will be invoked on your behalf. So you only need to explicitly pass currentTime 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 pixbufAnimationIterGetPixbuf and update the display with the new pixbuf.

getDelayTime

pixbufAnimationIterGetDelayTime

Arguments

:: (HasCallStack, MonadIO m, IsPixbufAnimationIter a)

=> a

iter: an animation iterator

-> m Int32

Returns: 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. 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.

getPixbuf

pixbufAnimationIterGetPixbuf

Arguments

:: (HasCallStack, MonadIO m, IsPixbufAnimationIter a)

=> a

iter: an animation iterator

-> m Pixbuf

Returns: the pixbuf to be displayed

Gets the current pixbuf which should be displayed; the pixbuf might not 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.

onCurrentlyLoadingFrame

pixbufAnimationIterOnCurrentlyLoadingFrame

Arguments

:: (HasCallStack, MonadIO m, IsPixbufAnimationIter a)

=> a

iter: a PixbufAnimationIter

-> m Bool

Returns: 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.