GI.Gdk.Objects.FrameClock

A FrameClock tells the application when to update and repaint a window. This may be synced to the vertical refresh rate of the monitor, for example. Even when the frame clock uses a simple timer rather than a hardware-based vertical sync, the frame clock helps because it ensures everything paints at the same time (reducing the total number of frames). The frame clock can also automatically stop painting when it knows the frames will not be visible, or scale back animation framerates.

FrameClock is designed to be compatible with an OpenGL-based implementation or with mozRequestAnimationFrame in Firefox, for example.

A frame clock is idle until someone requests a frame with frameClockRequestPhase. At some later point that makes sense for the synchronization being implemented, the clock will process a frame and emit signals for each phase that has been requested. (See the signals of the FrameClock class for documentation of the phases. FrameClockPhaseUpdate and the FrameClock::update signal are most interesting for application writers, and are used to update the animations, using the frame time given by frameClockGetFrameTime.

The frame time is reported in microseconds and generally in the same timescale as getMonotonicTime, however, it is not the same as getMonotonicTime. The frame time does not advance during the time a frame is being painted, and outside of a frame, an attempt is made so that all calls to frameClockGetFrameTime that are called at a “similar” time get the same value. This means that if different animations are timed by looking at the difference in time between an initial value from frameClockGetFrameTime and the value inside the FrameClock::update signal of the clock, they will stay exactly synchronized.

Exported types

newtype FrameClock

Memory-managed wrapper type.

Constructors

FrameClock (ManagedPtr FrameClock)

Instances

GObject FrameClock

Defined in GI.Gdk.Objects.FrameClock

Methods

gobjectType :: IO GType

HasParentTypes FrameClock

Defined in GI.Gdk.Objects.FrameClock

type ParentTypes FrameClock

Defined in GI.Gdk.Objects.FrameClock

type ParentTypes FrameClock = Object ': ([] :: [Type])

class (GObject o, IsDescendantOf FrameClock o) => IsFrameClock o

Type class for types which can be safely cast to FrameClock, for instance with toFrameClock.

Instances

(GObject o, IsDescendantOf FrameClock o) => IsFrameClock o

Defined in GI.Gdk.Objects.FrameClock

toFrameClock :: (MonadIO m, IsFrameClock o) => o -> m FrameClock

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

noFrameClock :: Maybe FrameClock

A convenience alias for Nothing :: Maybe FrameClock.

Methods

beginUpdating

frameClockBeginUpdating

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> m ()

Starts updates for an animation. Until a matching call to frameClockEndUpdating is made, the frame clock will continually request a new frame with the FrameClockPhaseUpdate phase. This function may be called multiple times and frames will be requested until frameClockEndUpdating is called the same number of times.

Since: 3.8

endUpdating

frameClockEndUpdating

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> m ()

Stops updates for an animation. See the documentation for frameClockBeginUpdating.

Since: 3.8

getCurrentTimings

frameClockGetCurrentTimings

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> m (Maybe FrameTimings)

Returns: the FrameTimings for the frame currently being processed, or even no frame is being processed, for the previous frame. Before any frames have been processed, returns Nothing.

Gets the frame timings for the current frame.

Since: 3.8

getFrameCounter

frameClockGetFrameCounter

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> m Int64

Returns: inside frame processing, the value of the frame counter for the current frame. Outside of frame processing, the frame counter for the last frame.

A FrameClock maintains a 64-bit counter that increments for each frame drawn.

Since: 3.8

getFrameTime

frameClockGetFrameTime

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> m Int64

Returns: a timestamp in microseconds, in the timescale of of getMonotonicTime.

Gets the time that should currently be used for animations. Inside the processing of a frame, it’s the time used to compute the animation position of everything in a frame. Outside of a frame, it's the time of the conceptual “previous frame,” which may be either the actual previous frame time, or if that’s too old, an updated time.

Since: 3.8

getHistoryStart

frameClockGetHistoryStart

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> m Int64

Returns: the frame counter value for the oldest frame that is available in the internal frame history of the FrameClock.

FrameClock internally keeps a history of FrameTimings objects for recent frames that can be retrieved with frameClockGetTimings. The set of stored frames is the set from the counter values given by frameClockGetHistoryStart and frameClockGetFrameCounter, inclusive.

Since: 3.8

getRefreshInfo

frameClockGetRefreshInfo

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> Int64

baseTime: base time for determining a presentaton time

-> m (Int64, Int64)

Using the frame history stored in the frame clock, finds the last known presentation time and refresh interval, and assuming that presentation times are separated by the refresh interval, predicts a presentation time that is a multiple of the refresh interval after the last presentation time, and later than baseTime.

Since: 3.8

getTimings

frameClockGetTimings

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> Int64

frameCounter: the frame counter value identifying the frame to be received.

-> m (Maybe FrameTimings)

Returns: the FrameTimings object for the specified frame, or Nothing if it is not available. See frameClockGetHistoryStart.

Retrieves a FrameTimings object holding timing information for the current frame or a recent frame. The FrameTimings object may not yet be complete: see frameTimingsGetComplete.

Since: 3.8

requestPhase

frameClockRequestPhase

Arguments

:: (HasCallStack, MonadIO m, IsFrameClock a)

=> a

frameClock: a FrameClock

-> [FrameClockPhase]

phase: the phase that is requested

-> m ()

Asks the frame clock to run a particular phase. The signal corresponding the requested phase will be emitted the next time the frame clock processes. Multiple calls to frameClockRequestPhase will be combined together and only one frame processed. If you are displaying animated content and want to continually request the FrameClockPhaseUpdate phase for a period of time, you should use frameClockBeginUpdating instead, since this allows GTK+ to adjust system parameters to get maximally smooth animations.

Since: 3.8

Signals

afterPaint

type C_FrameClockAfterPaintCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type FrameClockAfterPaintCallback = IO ()

This signal ends processing of the frame. Applications should generally not handle this signal.

afterFrameClockAfterPaint :: (IsFrameClock a, MonadIO m) => a -> FrameClockAfterPaintCallback -> m SignalHandlerId

Connect a signal handler for the “after-paint” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after frameClock #afterPaint callback

genClosure_FrameClockAfterPaint :: MonadIO m => FrameClockAfterPaintCallback -> m (GClosure C_FrameClockAfterPaintCallback)

Wrap the callback into a GClosure.

mk_FrameClockAfterPaintCallback :: C_FrameClockAfterPaintCallback -> IO (FunPtr C_FrameClockAfterPaintCallback)

Generate a function pointer callable from C code, from a C_FrameClockAfterPaintCallback.

noFrameClockAfterPaintCallback :: Maybe FrameClockAfterPaintCallback

A convenience synonym for Nothing :: Maybe FrameClockAfterPaintCallback.

onFrameClockAfterPaint :: (IsFrameClock a, MonadIO m) => a -> FrameClockAfterPaintCallback -> m SignalHandlerId

Connect a signal handler for the “after-paint” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on frameClock #afterPaint callback

wrap_FrameClockAfterPaintCallback :: FrameClockAfterPaintCallback -> C_FrameClockAfterPaintCallback

Wrap a FrameClockAfterPaintCallback into a C_FrameClockAfterPaintCallback.

beforePaint

type C_FrameClockBeforePaintCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type FrameClockBeforePaintCallback = IO ()

This signal begins processing of the frame. Applications should generally not handle this signal.

afterFrameClockBeforePaint :: (IsFrameClock a, MonadIO m) => a -> FrameClockBeforePaintCallback -> m SignalHandlerId

Connect a signal handler for the “before-paint” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after frameClock #beforePaint callback

genClosure_FrameClockBeforePaint :: MonadIO m => FrameClockBeforePaintCallback -> m (GClosure C_FrameClockBeforePaintCallback)

Wrap the callback into a GClosure.

mk_FrameClockBeforePaintCallback :: C_FrameClockBeforePaintCallback -> IO (FunPtr C_FrameClockBeforePaintCallback)

Generate a function pointer callable from C code, from a C_FrameClockBeforePaintCallback.

noFrameClockBeforePaintCallback :: Maybe FrameClockBeforePaintCallback

A convenience synonym for Nothing :: Maybe FrameClockBeforePaintCallback.

onFrameClockBeforePaint :: (IsFrameClock a, MonadIO m) => a -> FrameClockBeforePaintCallback -> m SignalHandlerId

Connect a signal handler for the “before-paint” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on frameClock #beforePaint callback

wrap_FrameClockBeforePaintCallback :: FrameClockBeforePaintCallback -> C_FrameClockBeforePaintCallback

Wrap a FrameClockBeforePaintCallback into a C_FrameClockBeforePaintCallback.

flushEvents

type C_FrameClockFlushEventsCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type FrameClockFlushEventsCallback = IO ()

This signal is used to flush pending motion events that are being batched up and compressed together. Applications should not handle this signal.

afterFrameClockFlushEvents :: (IsFrameClock a, MonadIO m) => a -> FrameClockFlushEventsCallback -> m SignalHandlerId

Connect a signal handler for the “flush-events” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after frameClock #flushEvents callback

genClosure_FrameClockFlushEvents :: MonadIO m => FrameClockFlushEventsCallback -> m (GClosure C_FrameClockFlushEventsCallback)

Wrap the callback into a GClosure.

mk_FrameClockFlushEventsCallback :: C_FrameClockFlushEventsCallback -> IO (FunPtr C_FrameClockFlushEventsCallback)

Generate a function pointer callable from C code, from a C_FrameClockFlushEventsCallback.

noFrameClockFlushEventsCallback :: Maybe FrameClockFlushEventsCallback

A convenience synonym for Nothing :: Maybe FrameClockFlushEventsCallback.

onFrameClockFlushEvents :: (IsFrameClock a, MonadIO m) => a -> FrameClockFlushEventsCallback -> m SignalHandlerId

Connect a signal handler for the “flush-events” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on frameClock #flushEvents callback

wrap_FrameClockFlushEventsCallback :: FrameClockFlushEventsCallback -> C_FrameClockFlushEventsCallback

Wrap a FrameClockFlushEventsCallback into a C_FrameClockFlushEventsCallback.

layout

type C_FrameClockLayoutCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type FrameClockLayoutCallback = IO ()

This signal is emitted as the second step of toolkit and application processing of the frame. Any work to update sizes and positions of application elements should be performed. GTK+ normally handles this internally.

afterFrameClockLayout :: (IsFrameClock a, MonadIO m) => a -> FrameClockLayoutCallback -> m SignalHandlerId

Connect a signal handler for the “layout” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after frameClock #layout callback

genClosure_FrameClockLayout :: MonadIO m => FrameClockLayoutCallback -> m (GClosure C_FrameClockLayoutCallback)

Wrap the callback into a GClosure.

mk_FrameClockLayoutCallback :: C_FrameClockLayoutCallback -> IO (FunPtr C_FrameClockLayoutCallback)

Generate a function pointer callable from C code, from a C_FrameClockLayoutCallback.

noFrameClockLayoutCallback :: Maybe FrameClockLayoutCallback

A convenience synonym for Nothing :: Maybe FrameClockLayoutCallback.

onFrameClockLayout :: (IsFrameClock a, MonadIO m) => a -> FrameClockLayoutCallback -> m SignalHandlerId

Connect a signal handler for the “layout” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on frameClock #layout callback

wrap_FrameClockLayoutCallback :: FrameClockLayoutCallback -> C_FrameClockLayoutCallback

Wrap a FrameClockLayoutCallback into a C_FrameClockLayoutCallback.

paint

type C_FrameClockPaintCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type FrameClockPaintCallback = IO ()

This signal is emitted as the third step of toolkit and application processing of the frame. The frame is repainted. GDK normally handles this internally and produces expose events, which are turned into GTK+ GtkWidget::draw signals.

afterFrameClockPaint :: (IsFrameClock a, MonadIO m) => a -> FrameClockPaintCallback -> m SignalHandlerId

Connect a signal handler for the “paint” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after frameClock #paint callback

genClosure_FrameClockPaint :: MonadIO m => FrameClockPaintCallback -> m (GClosure C_FrameClockPaintCallback)

Wrap the callback into a GClosure.

mk_FrameClockPaintCallback :: C_FrameClockPaintCallback -> IO (FunPtr C_FrameClockPaintCallback)

Generate a function pointer callable from C code, from a C_FrameClockPaintCallback.

noFrameClockPaintCallback :: Maybe FrameClockPaintCallback

A convenience synonym for Nothing :: Maybe FrameClockPaintCallback.

onFrameClockPaint :: (IsFrameClock a, MonadIO m) => a -> FrameClockPaintCallback -> m SignalHandlerId

Connect a signal handler for the “paint” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on frameClock #paint callback

wrap_FrameClockPaintCallback :: FrameClockPaintCallback -> C_FrameClockPaintCallback

Wrap a FrameClockPaintCallback into a C_FrameClockPaintCallback.

resumeEvents

type C_FrameClockResumeEventsCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type FrameClockResumeEventsCallback = IO ()

This signal is emitted after processing of the frame is finished, and is handled internally by GTK+ to resume normal event processing. Applications should not handle this signal.

afterFrameClockResumeEvents :: (IsFrameClock a, MonadIO m) => a -> FrameClockResumeEventsCallback -> m SignalHandlerId

Connect a signal handler for the “resume-events” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after frameClock #resumeEvents callback

genClosure_FrameClockResumeEvents :: MonadIO m => FrameClockResumeEventsCallback -> m (GClosure C_FrameClockResumeEventsCallback)

Wrap the callback into a GClosure.

mk_FrameClockResumeEventsCallback :: C_FrameClockResumeEventsCallback -> IO (FunPtr C_FrameClockResumeEventsCallback)

Generate a function pointer callable from C code, from a C_FrameClockResumeEventsCallback.

noFrameClockResumeEventsCallback :: Maybe FrameClockResumeEventsCallback

A convenience synonym for Nothing :: Maybe FrameClockResumeEventsCallback.

onFrameClockResumeEvents :: (IsFrameClock a, MonadIO m) => a -> FrameClockResumeEventsCallback -> m SignalHandlerId

Connect a signal handler for the “resume-events” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on frameClock #resumeEvents callback

wrap_FrameClockResumeEventsCallback :: FrameClockResumeEventsCallback -> C_FrameClockResumeEventsCallback

Wrap a FrameClockResumeEventsCallback into a C_FrameClockResumeEventsCallback.

update

type C_FrameClockUpdateCallback = Ptr () -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type FrameClockUpdateCallback = IO ()

This signal is emitted as the first step of toolkit and application processing of the frame. Animations should be updated using frameClockGetFrameTime. Applications can connect directly to this signal, or use gtk_widget_add_tick_callback() as a more convenient interface.

afterFrameClockUpdate :: (IsFrameClock a, MonadIO m) => a -> FrameClockUpdateCallback -> m SignalHandlerId

Connect a signal handler for the “update” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after frameClock #update callback

genClosure_FrameClockUpdate :: MonadIO m => FrameClockUpdateCallback -> m (GClosure C_FrameClockUpdateCallback)

Wrap the callback into a GClosure.

mk_FrameClockUpdateCallback :: C_FrameClockUpdateCallback -> IO (FunPtr C_FrameClockUpdateCallback)

Generate a function pointer callable from C code, from a C_FrameClockUpdateCallback.

noFrameClockUpdateCallback :: Maybe FrameClockUpdateCallback

A convenience synonym for Nothing :: Maybe FrameClockUpdateCallback.

onFrameClockUpdate :: (IsFrameClock a, MonadIO m) => a -> FrameClockUpdateCallback -> m SignalHandlerId

Connect a signal handler for the “update” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on frameClock #update callback

wrap_FrameClockUpdateCallback :: FrameClockUpdateCallback -> C_FrameClockUpdateCallback

Wrap a FrameClockUpdateCallback into a C_FrameClockUpdateCallback.