FrameClock

A gdk.frame_clock.FrameClock tells the application when to update and repaint a surface.

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.

gdk.frame_clock.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 gdk.frame_clock.FrameClock.requestPhase. 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 gdk.frame_clock.FrameClock class for documentation of the phases. gdk.types.FrameClockPhase.Update and the gdk.frame_clock.FrameClock.update signal are most interesting for application writers, and are used to update the animations, using the frame time given by gdk.frame_clock.FrameClock.getFrameTime.

The frame time is reported in microseconds and generally in the same timescale as glib.global.getMonotonicTime, however, it is not the same as glib.global.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 gdk.frame_clock.FrameClock.getFrameTime 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 gdk.frame_clock.FrameClock.getFrameTime and the value inside the gdk.frame_clock.FrameClock.update signal of the clock, they will stay exactly synchronized.

class FrameClock : ObjectG {

void beginUpdating();

void endUpdating();

gdk.frame_timings.FrameTimings getCurrentTimings();

double getFps();

long getFrameCounter();

long getFrameTime();

long getHistoryStart();

void getRefreshInfo(long baseTime, long refreshIntervalReturn, long presentationTimeReturn);

gdk.frame_timings.FrameTimings getTimings(long frameCounter);

void requestPhase(gdk.types.FrameClockPhase phase);

ulong connectAfterPaint(T callback, Flag!"After" after);

ulong connectBeforePaint(T callback, Flag!"After" after);

ulong connectFlushEvents(T callback, Flag!"After" after);

ulong connectLayout(T callback, Flag!"After" after);

ulong connectPaint(T callback, Flag!"After" after);

ulong connectResumeEvents(T callback, Flag!"After" after);

ulong connectUpdate(T callback, Flag!"After" after);

}

Members

Functions

beginUpdating void beginUpdating(): Starts updates for an animation.
connectAfterPaint ulong connectAfterPaint(T callback, Flag!"After" after): Connect to AfterPaint signal.
connectBeforePaint ulong connectBeforePaint(T callback, Flag!"After" after): Connect to BeforePaint signal.
connectFlushEvents ulong connectFlushEvents(T callback, Flag!"After" after): Connect to FlushEvents signal.
connectLayout ulong connectLayout(T callback, Flag!"After" after): Connect to Layout signal.
connectPaint ulong connectPaint(T callback, Flag!"After" after): Connect to Paint signal.
connectResumeEvents ulong connectResumeEvents(T callback, Flag!"After" after): Connect to ResumeEvents signal.
connectUpdate ulong connectUpdate(T callback, Flag!"After" after): Connect to Update signal.
endUpdating void endUpdating(): Stops updates for an animation.
getCurrentTimings gdk.frame_timings.FrameTimings getCurrentTimings(): Gets the frame timings for the current frame.
getFps double getFps(): Calculates the current frames-per-second, based on the frame timings of frame_clock.
getFrameCounter long getFrameCounter(): gdk.frame_clock.FrameClock maintains a 64-bit counter that increments for each frame drawn.
getFrameTime long getFrameTime(): Gets the time that should currently be used for animations.
getHistoryStart long getHistoryStart(): Returns the frame counter for the oldest frame available in history.
getRefreshInfo void getRefreshInfo(long baseTime, long refreshIntervalReturn, long presentationTimeReturn): Predicts a presentation time, based on history.
getTimings gdk.frame_timings.FrameTimings getTimings(long frameCounter): Retrieves a gdk.frame_timings.FrameTimings object holding timing information for the current frame or a recent frame.
requestPhase void requestPhase(gdk.types.FrameClockPhase phase): Asks the frame clock to run a particular phase.

Inherited Members

From ObjectG

setGObject void setGObject(void* cObj, Flag!"Take" take): Set the GObject of a D ObjectG wrapper.
cPtr void* cPtr(Flag!"Dup" dup): Get a pointer to the underlying C object.
ref_ void* ref_(void* gObj): Calls g_object_ref() on a GObject.
unref unref(void* gObj): Calls g_object_unref() on a GObject.
getType GType getType(): Get the GType of an object.
gType GType gType [@property getter]: GObject GType property.
self ObjectG self(): Convenience method to return this cast to a type. For use in D with statements.
getDObject T getDObject(void* cptr, Flag!"Take" take): Template to get the D object from a C GObject and cast it to the given D object type.
connectSignalClosure ulong connectSignalClosure(string signalDetail, DClosure closure, Flag!"After" after): Connect a D closure to an object signal.
setProperty void setProperty(string propertyName, T val): Template for setting a GObject property.
getProperty T getProperty(string propertyName): Template for getting a GObject property.
compatControl size_t compatControl(size_t what, void* data)
bindProperty gobject.binding.Binding bindProperty(string sourceProperty, gobject.object.ObjectG target, string targetProperty, gobject.types.BindingFlags flags): Creates a binding between source_property on source and target_property on target.
bindPropertyFull gobject.binding.Binding bindPropertyFull(string sourceProperty, gobject.object.ObjectG target, string targetProperty, gobject.types.BindingFlags flags, gobject.closure.Closure transformTo, gobject.closure.Closure transformFrom): Creates a binding between source_property on source and target_property on target, allowing you to set the transformation functions to be used by the binding.
forceFloating void forceFloating(): This function is intended for #GObject implementations to re-enforce a floating[floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling gobject.object.ObjectG.refSink.
freezeNotify void freezeNotify(): Increases the freeze count on object. If the freeze count is non-zero, the emission of "notify" signals on object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one #GObject::notify signal is emitted for each property modified while the object is frozen.
getData void* getData(string key): Gets a named field from the objects table of associations (see gobject.object.ObjectG.setData).
getProperty void getProperty(string propertyName, gobject.value.Value value): Gets a property of an object.
getQdata void* getQdata(glib.types.Quark quark): This function gets back user data pointers stored via gobject.object.ObjectG.setQdata.
getv void getv(string[] names, gobject.value.Value[] values): Gets n_properties properties for an object. Obtained properties will be set to values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.
isFloating bool isFloating(): Checks whether object has a floating[floating-ref] reference.
notify void notify(string propertyName): Emits a "notify" signal for the property property_name on object.
notifyByPspec void notifyByPspec(gobject.param_spec.ParamSpec pspec): Emits a "notify" signal for the property specified by pspec on object.
refSink gobject.object.ObjectG refSink(): Increase the reference count of object, and possibly remove the floating[floating-ref] reference, if object has a floating reference.
runDispose void runDispose(): Releases all references to other objects. This can be used to break reference cycles.
setData void setData(string key, void* data): Each object carries around a table of associations from strings to pointers. This function lets you set an association.
setProperty void setProperty(string propertyName, gobject.value.Value value): Sets a property on an object.
stealData void* stealData(string key): Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
stealQdata void* stealQdata(glib.types.Quark quark): This function gets back user data pointers stored via gobject.object.ObjectG.setQdata and removes the data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example:
thawNotify void thawNotify(): Reverts the effect of a previous call to gobject.object.ObjectG.freezeNotify. The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted.
watchClosure void watchClosure(gobject.closure.Closure closure): This function essentially limits the life time of the closure to the life time of the object. That is, when the object is finalized, the closure is invalidated by calling gobject.closure.Closure.invalidate on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, gobject.object.ObjectG.ref_ and gobject.object.ObjectG.unref are added as marshal guards to the closure, to ensure that an extra reference count is held on object during invocation of the closure. Usually, this function will be called on closures that use this object as closure data.
connectNotify ulong connectNotify(string detail, T callback, Flag!"After" after): Connect to Notify signal.

gdk frame_clock classes

FrameClock