C++ UpdateTiming函数代码示例

void
Animation::Tick()
{
  // Finish pending if we have a pending ready time, but only if we also
  // have an active timeline.
  if (mPendingState != PendingState::NotPending &&
      !mPendingReadyTime.IsNull() &&
      mTimeline &&
      !mTimeline->GetCurrentTime().IsNull()) {
    // Even though mPendingReadyTime is initialized using TimeStamp::Now()
    // during the *previous* tick of the refresh driver, it can still be
    // ahead of the *current* timeline time when we are using the
    // vsync timer so we need to clamp it to the timeline time.
    mPendingReadyTime.SetValue(std::min(mTimeline->GetCurrentTime().Value(),
                                        mPendingReadyTime.Value()));
    FinishPendingAt(mPendingReadyTime.Value());
    mPendingReadyTime.SetNull();
  }

  if (IsPossiblyOrphanedPendingAnimation()) {
    MOZ_ASSERT(mTimeline && !mTimeline->GetCurrentTime().IsNull(),
               "Orphaned pending animtaions should have an active timeline");
    FinishPendingAt(mTimeline->GetCurrentTime().Value());
  }

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);

  // Update layers if we are newly finished.
  if (mEffect &&
      !mEffect->Properties().IsEmpty() &&
      !mFinishedAtLastComposeStyle &&
      PlayState() == AnimationPlayState::Finished) {
    PostUpdate();
  }
}

void
Animation::ResumeAt(const TimeDuration& aReadyTime)
{
  // This method is only expected to be called for an animation that is
  // waiting to play. We can easily adapt it to handle other states
  // but it's currently not necessary.
  MOZ_ASSERT(mPendingState == PendingState::PlayPending,
             "Expected to resume a play-pending animation");
  MOZ_ASSERT(mHoldTime.IsNull() != mStartTime.IsNull(),
             "An animation in the play-pending state should have either a"
             " resolved hold time or resolved start time (but not both)");

  // If we aborted a pending pause operation we will already have a start time
  // we should use. In all other cases, we resolve it from the ready time.
  if (mStartTime.IsNull()) {
    if (mPlaybackRate != 0) {
      mStartTime.SetValue(aReadyTime -
                          (mHoldTime.Value().MultDouble(1 / mPlaybackRate)));
      mHoldTime.SetNull();
    } else {
      mStartTime.SetValue(aReadyTime);
    }
  }
  mPendingState = PendingState::NotPending;

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);

  if (mReady) {
    mReady->MaybeResolve(this);
  }
}

// https://w3c.github.io/web-animations/#set-the-current-time
void
Animation::SetCurrentTime(const TimeDuration& aSeekTime)
{
  // Return early if the current time has not changed. However, if we
  // are pause-pending, then setting the current time to any value
  // including the current value has the effect of aborting the
  // pause so we should not return early in that case.
  if (mPendingState != PendingState::PausePending &&
      Nullable<TimeDuration>(aSeekTime) == GetCurrentTime()) {
    return;
  }

  AutoMutationBatchForAnimation mb(*this);

  SilentlySetCurrentTime(aSeekTime);

  if (mPendingState == PendingState::PausePending) {
    // Finish the pause operation
    mHoldTime.SetValue(aSeekTime);
    mStartTime.SetNull();

    if (mReady) {
      mReady->MaybeResolve(this);
    }
    CancelPendingTasks();
  }

  UpdateTiming(SeekFlag::DidSeek, SyncNotifyFlag::Async);
  if (IsRelevant()) {
    nsNodeUtils::AnimationChanged(this);
  }
  PostUpdate();
}

// https://w3c.github.io/web-animations/#cancel-an-animation
void
Animation::CancelNoUpdate()
{
  if (mPendingState != PendingState::NotPending) {
    CancelPendingTasks();
    if (mReady) {
      mReady->MaybeReject(NS_ERROR_DOM_ABORT_ERR);
    }
  }

  if (mFinished) {
    mFinished->MaybeReject(NS_ERROR_DOM_ABORT_ERR);
  }
  ResetFinishedPromise();

  DispatchPlaybackEvent(NS_LITERAL_STRING("cancel"));

  mHoldTime.SetNull();
  mStartTime.SetNull();

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);

  if (mTimeline) {
    mTimeline->RemoveAnimation(this);
  }
}

// https://w3c.github.io/web-animations/#set-the-animation-playback-rate
void
Animation::SetPlaybackRate(double aPlaybackRate)
{
  if (aPlaybackRate == mPlaybackRate) {
    return;
  }

  AutoMutationBatchForAnimation mb(*this);

  Nullable<TimeDuration> previousTime = GetCurrentTime();
  mPlaybackRate = aPlaybackRate;
  if (!previousTime.IsNull()) {
    SetCurrentTime(previousTime.Value());
  }

  // In the case where GetCurrentTime() returns the same result before and
  // after updating mPlaybackRate, SetCurrentTime will return early since,
  // as far as it can tell, nothing has changed.
  // As a result, we need to perform the following updates here:
  // - update timing (since, if the sign of the playback rate has changed, our
  //   finished state may have changed),
  // - dispatch a change notification for the changed playback rate, and
  // - update the playback rate on animations on layers.
  UpdateTiming(SeekFlag::DidSeek, SyncNotifyFlag::Async);
  if (IsRelevant()) {
    nsNodeUtils::AnimationChanged(this);
  }
  PostUpdate();
}

void
Animation::Tick()
{
  // Since we are not guaranteed to get only one call per refresh driver tick,
  // it's possible that mPendingReadyTime is set to a time in the future.
  // In that case, we should wait until the next refresh driver tick before
  // resuming.
  if (mPendingState != PendingState::NotPending &&
      !mPendingReadyTime.IsNull() &&
      mTimeline &&
      !mTimeline->GetCurrentTime().IsNull() &&
      mPendingReadyTime.Value() <= mTimeline->GetCurrentTime().Value()) {
    FinishPendingAt(mPendingReadyTime.Value());
    mPendingReadyTime.SetNull();
  }

  if (IsPossiblyOrphanedPendingAnimation()) {
    MOZ_ASSERT(mTimeline && !mTimeline->GetCurrentTime().IsNull(),
               "Orphaned pending animtaions should have an active timeline");
    FinishPendingAt(mTimeline->GetCurrentTime().Value());
  }

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);

  // FIXME: Detect the no-change case and don't request a restyle at all
  // FIXME: Detect changes to IsPlaying() state and request RestyleType::Layer
  //        so that layers get updated immediately
  AnimationCollection* collection = GetCollection();
  if (collection) {
    collection->RequestRestyle(CanThrottle() ?
      AnimationCollection::RestyleType::Throttled :
      AnimationCollection::RestyleType::Standard);
  }
}

void
Animation::NotifyEffectTimingUpdated()
{
  MOZ_ASSERT(mEffect,
             "We should only update timing effect when we have a target "
             "effect");
  UpdateTiming(Animation::SeekFlag::NoSeek,
               Animation::SyncNotifyFlag::Async);
}

// https://w3c.github.io/web-animations/#finish-an-animation
void
Animation::Finish(ErrorResult& aRv)
{
  if (mPlaybackRate == 0 ||
      (mPlaybackRate > 0 && EffectEnd() == TimeDuration::Forever())) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  AutoMutationBatchForAnimation mb(*this);

  // Seek to the end
  TimeDuration limit =
    mPlaybackRate > 0 ? TimeDuration(EffectEnd()) : TimeDuration(0);
  bool didChange = GetCurrentTime() != Nullable<TimeDuration>(limit);
  SilentlySetCurrentTime(limit);

  // If we are paused or play-pending we need to fill in the start time in
  // order to transition to the finished state.
  //
  // We only do this, however, if we have an active timeline. If we have an
  // inactive timeline we can't transition into the finished state just like
  // we can't transition to the running state (this finished state is really
  // a substate of the running state).
  if (mStartTime.IsNull() &&
      mTimeline &&
      !mTimeline->GetCurrentTime().IsNull()) {
    mStartTime.SetValue(mTimeline->GetCurrentTime().Value() -
                        limit.MultDouble(1.0 / mPlaybackRate));
    didChange = true;
  }

  // If we just resolved the start time for a pause or play-pending
  // animation, we need to clear the task. We don't do this as a branch of
  // the above however since we can have a play-pending animation with a
  // resolved start time if we aborted a pause operation.
  if (!mStartTime.IsNull() &&
      (mPendingState == PendingState::PlayPending ||
       mPendingState == PendingState::PausePending)) {
    if (mPendingState == PendingState::PausePending) {
      mHoldTime.SetNull();
    }
    CancelPendingTasks();
    didChange = true;
    if (mReady) {
      mReady->MaybeResolve(this);
    }
  }
  UpdateTiming(SeekFlag::DidSeek, SyncNotifyFlag::Sync);
  if (didChange && IsRelevant()) {
    nsNodeUtils::AnimationChanged(this);
  }
  PostUpdate();
}

// https://w3c.github.io/web-animations/#pause-an-animation
void
Animation::DoPause(ErrorResult& aRv)
{
  if (IsPausedOrPausing()) {
    return;
  }

  AutoMutationBatchForAnimation mb(*this);

  // If we are transitioning from idle, fill in the current time
  if (GetCurrentTime().IsNull()) {
    if (mPlaybackRate >= 0.0) {
      mHoldTime.SetValue(TimeDuration(0));
    } else {
      if (EffectEnd() == TimeDuration::Forever()) {
        aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
        return;
      }
      mHoldTime.SetValue(TimeDuration(EffectEnd()));
    }
  }

  bool reuseReadyPromise = false;
  if (mPendingState == PendingState::PlayPending) {
    CancelPendingTasks();
    reuseReadyPromise = true;
  }

  if (!reuseReadyPromise) {
    // Clear ready promise. We'll create a new one lazily.
    mReady = nullptr;
  }

  mPendingState = PendingState::PausePending;

  nsIDocument* doc = GetRenderedDocument();
  if (doc) {
    PendingAnimationTracker* tracker =
      doc->GetOrCreatePendingAnimationTracker();
    tracker->AddPausePending(*this);
  } else {
    TriggerOnNextTick(Nullable<TimeDuration>());
  }

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);
  if (IsRelevant()) {
    nsNodeUtils::AnimationChanged(this);
  }
}

// http://w3c.github.io/web-animations/#pause-an-animation
void
Animation::DoPause(ErrorResult& aRv)
{
  if (IsPausedOrPausing()) {
    return;
  }

  // If we are transitioning from idle, fill in the current time
  if (GetCurrentTime().IsNull()) {
    if (mPlaybackRate >= 0.0) {
      mHoldTime.SetValue(TimeDuration(0));
    } else {
      if (EffectEnd() == TimeDuration::Forever()) {
        aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
        return;
      }
      mHoldTime.SetValue(TimeDuration(EffectEnd()));
    }
  }

  bool reuseReadyPromise = false;
  if (mPendingState == PendingState::PlayPending) {
    CancelPendingTasks();
    reuseReadyPromise = true;
  }

  // Mark this as no longer running on the compositor so that next time
  // we update animations we won't throttle them and will have a chance
  // to remove the animation from any layer it might be on.
  mIsRunningOnCompositor = false;

  if (!reuseReadyPromise) {
    // Clear ready promise. We'll create a new one lazily.
    mReady = nullptr;
  }

  mPendingState = PendingState::PausePending;

  nsIDocument* doc = GetRenderedDocument();
  if (doc) {
    PendingAnimationTracker* tracker =
      doc->GetOrCreatePendingAnimationTracker();
    tracker->AddPausePending(*this);
  } else {
    TriggerOnNextTick(Nullable<TimeDuration>());
  }

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);
}

void
Animation::SetEffect(KeyframeEffectReadOnly* aEffect)
{
  RefPtr<Animation> kungFuDeathGrip(this);

  if (mEffect == aEffect) {
    return;
  }
  if (mEffect) {
    mEffect->SetAnimation(nullptr);
  }
  mEffect = aEffect;
  if (mEffect) {
    mEffect->SetAnimation(this);
  }

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);
}

void MouseHelper::UpdateState(bool isLeftButtonDown, int mouseX, int mouseY, bool drawCursor)
{
    bool currentWasLeftButtonDown = isLeftButtonDown;

    // If we're in full-screen mode, then we need to account for the screen scale.
    if (gIsFullscreen)
    {
        mouseX = (int)(mouseX / gScreenScale);
        mouseY = (int)(mouseY / gScreenScale);
    }

    previousMousePosition.SetX(mouseX);
    previousMousePosition.SetY(mouseY);

    UpdateTiming();

    if (!currentWasLeftButtonDown && previousWasLeftButtonDown)
    {
        // If a click is still possible now that the button has gone up,
        // and we weren't already expecting a double-click,
        // then we have a click, and we'll start considering the possibility
        // of a double-click. If on the other hand a double-click was expected,
        // then we now have a double-click.
        clicked = clickPossible && !doubleClickPossible;
        doubleClicked = clickPossible && doubleClickPossible;
        doubleClickPossible = clickPossible && !doubleClickPossible;
        clickPossible = false;

        if (doubleClickPossible)
        {
            initialClickTime = SDL_GetTicks();
        }
    }
    else if (currentWasLeftButtonDown && !previousWasLeftButtonDown)
    {
        initialLeftButtonDownTime = SDL_GetTicks();
        initialLeftButtonDownPosition = previousMousePosition;
        clickPossible = true;
        doubleClickWasPossible = doubleClickPossible;
    }

    previousWasLeftButtonDown = currentWasLeftButtonDown;
    MouseHelper::drawCursor = drawCursor;
}

void
Animation::PauseAt(const TimeDuration& aReadyTime)
{
  MOZ_ASSERT(mPendingState == PendingState::PausePending,
             "Expected to pause a pause-pending animation");

  if (!mStartTime.IsNull()) {
    mHoldTime.SetValue((aReadyTime - mStartTime.Value())
                        .MultDouble(mPlaybackRate));
  }
  mStartTime.SetNull();
  mPendingState = PendingState::NotPending;

  UpdateTiming();

  if (mReady) {
    mReady->MaybeResolve(this);
  }
}

// https://w3c.github.io/web-animations/#setting-the-timeline
void
Animation::SetTimelineNoUpdate(AnimationTimeline* aTimeline)
{
  RefPtr<AnimationTimeline> oldTimeline = mTimeline;
  if (mTimeline == aTimeline) {
    return;
  }

  if (mTimeline) {
    mTimeline->RemoveAnimation(this);
  }

  mTimeline = aTimeline;
  if (!mStartTime.IsNull()) {
    mHoldTime.SetNull();
  }

  UpdateTiming(SeekFlag::NoSeek, SyncNotifyFlag::Async);
}

// Implements http://w3c.github.io/web-animations/#set-the-current-time
void
Animation::SetCurrentTime(const TimeDuration& aSeekTime)
{
  SilentlySetCurrentTime(aSeekTime);

  if (mPendingState == PendingState::PausePending) {
    // Finish the pause operation
    mHoldTime.SetValue(aSeekTime);
    mStartTime.SetNull();

    if (mReady) {
      mReady->MaybeResolve(this);
    }
    CancelPendingTasks();
  }

  UpdateTiming(SeekFlag::DidSeek, SyncNotifyFlag::Async);
  PostUpdate();
}