VSyncClient Class Reference

#import <vsync_waiter_ios.h>

Inheritance diagram for VSyncClient:

Instance Methods
(instancetype)	- initWithTaskRunner:callback:
(void)	- await
(void)	- pause
(void)	- invalidate
	Call invalidate before releasing this object to remove from runloops. More...
(void)	- setMaxRefreshRate:
(void)	- onDisplayLink: [implementation]
(CADisplayLink *)	- getDisplayLink [implementation]

Properties
BOOL	allowPauseAfterVsync
	Default value is YES. Vsync client will pause vsync callback after receiving a vsync signal. Setting this property to NO can avoid this and vsync client will trigger vsync callback continuously. More...
double	refreshRate [implementation]

Detailed Description

Definition at line 36 of file vsync_waiter_ios.h.

Method Documentation

await

- (void) await

Definition at line 66 of file vsync_waiter_ios.mm.

              {
  _displayLink.paused = NO;
}

getDisplayLink

- (CADisplayLink *) getDisplayLink

implementation

Provided by category VSyncClient(Testing).

Definition at line 66 of file vsync_waiter_ios.mm.

                                 {
  return _displayLink;
}

initWithTaskRunner:callback:

- (instancetype) initWithTaskRunner:		(fml::RefPtr<fml::TaskRunner>)	task_runner
callback:		(flutter::VsyncWaiter::Callback)	callback

Definition at line 66 of file vsync_waiter_ios.mm.

                                  :(fml::RefPtr<fml::TaskRunner>)task_runner
                          callback:(flutter::VsyncWaiter::Callback)callback {
  self = [super init];
 
  if (self) {
    _refreshRate = DisplayLinkManager.displayRefreshRate;
    _allowPauseAfterVsync = YES;
    _callback = std::move(callback);
    _displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(onDisplayLink:)];
    _displayLink.paused = YES;
 
    [self setMaxRefreshRate:DisplayLinkManager.displayRefreshRate];
 
    // Strongly retain the the captured link until it is added to the runloop.
    CADisplayLink* localDisplayLink = _displayLink;
    task_runner->PostTask([localDisplayLink]() {
      [localDisplayLink addToRunLoop:NSRunLoop.currentRunLoop forMode:NSRunLoopCommonModes];
    });
  }
 
  return self;
}

invalidate

- (void) invalidate

Call invalidate before releasing this object to remove from runloops.

Definition at line 66 of file vsync_waiter_ios.mm.

                   {
  [_displayLink invalidate];
  _displayLink = nil;  // Break retain cycle.
}

onDisplayLink:

- (void) onDisplayLink: (CADisplayLink*)  link

implementation

Provided by category VSyncClient(Testing).

Definition at line 66 of file vsync_waiter_ios.mm.

                     :(CADisplayLink*)link {
  CFTimeInterval delay = CACurrentMediaTime() - link.timestamp;
  fml::TimePoint frame_start_time = fml::TimePoint::Now() - fml::TimeDelta::FromSecondsF(delay);
 
  CFTimeInterval duration = link.targetTimestamp - link.timestamp;
  fml::TimePoint frame_target_time = frame_start_time + fml::TimeDelta::FromSecondsF(duration);
 
  TRACE_EVENT2_INT("flutter", "PlatformVsync", "frame_start_time",
                   frame_start_time.ToEpochDelta().ToMicroseconds(), "frame_target_time",
                   frame_target_time.ToEpochDelta().ToMicroseconds());
 
  std::unique_ptr<flutter::FrameTimingsRecorder> recorder =
      std::make_unique<flutter::FrameTimingsRecorder>();
 
  _refreshRate = round(1 / (frame_target_time - frame_start_time).ToSecondsF());
 
  recorder->RecordVsync(frame_start_time, frame_target_time);
  if (_allowPauseAfterVsync) {
    link.paused = YES;
  }
  _callback(std::move(recorder));
}

pause

- (void) pause

Definition at line 66 of file vsync_waiter_ios.mm.

              {
  _displayLink.paused = YES;
}

setMaxRefreshRate:

- (void) setMaxRefreshRate:

(double)

refreshRate

Definition at line 66 of file vsync_waiter_ios.mm.

                         :(double)refreshRate {
  if (!DisplayLinkManager.maxRefreshRateEnabledOnIPhone) {
    return;
  }
  double maxFrameRate = fmax(refreshRate, 60);
  double minFrameRate = fmax(maxFrameRate / 2, 60);
  if (@available(iOS 15.0, *)) {
    _displayLink.preferredFrameRateRange =
        CAFrameRateRangeMake(minFrameRate, maxFrameRate, maxFrameRate);
  } else {
    _displayLink.preferredFramesPerSecond = maxFrameRate;
  }
}

Property Documentation

allowPauseAfterVsync

- (BOOL) allowPauseAfterVsync

readwritenonatomicassign

Default value is YES. Vsync client will pause vsync callback after receiving a vsync signal. Setting this property to NO can avoid this and vsync client will trigger vsync callback continuously.

Parameters

allowPauseAfterVsync

Allow vsync client to pause after receiving a vsync signal.

Definition at line 46 of file vsync_waiter_ios.h.

refreshRate

- (double) refreshRate

readnonatomicassignimplementation

Definition at line 22 of file vsync_waiter_ios.mm.

---

The documentation for this class was generated from the following files:

• shell/platform/darwin/ios/framework/Source/vsync_waiter_ios.h
• shell/platform/darwin/ios/framework/Source/vsync_waiter_ios.mm