C++ (Cpp) FrameMetrics::AllowVerticalScrollWithWheel Examples

Example #1

File: WheelScrollAnimation.cpp Project: chirimen-oh/gecko-dev

bool
WheelScrollAnimation::DoSample(FrameMetrics& aFrameMetrics, const TimeDuration& aDelta)
{
  TimeStamp now = AsyncPanZoomController::GetFrameTime();
  CSSToParentLayerScale2D zoom = aFrameMetrics.GetZoom();

  // If the animation is finished, make sure the final position is correct by
  // using one last displacement. Otherwise, compute the delta via the timing
  // function as normal.
  bool finished = IsFinished(now);
  nsPoint sampledDest = finished
                        ? mDestination
                        : PositionAt(now);
  ParentLayerPoint displacement =
    (CSSPoint::FromAppUnits(sampledDest) - aFrameMetrics.GetScrollOffset()) * zoom;

  // Note: we ignore overscroll for wheel animations.
  ParentLayerPoint adjustedOffset, overscroll;
  mApzc.mX.AdjustDisplacement(displacement.x, adjustedOffset.x, overscroll.x);
  mApzc.mY.AdjustDisplacement(displacement.y, adjustedOffset.y, overscroll.y,
                              !aFrameMetrics.AllowVerticalScrollWithWheel());
  if (IsZero(adjustedOffset)) {
    // Nothing more to do - end the animation.
    return false;
  }

  aFrameMetrics.ScrollBy(adjustedOffset / zoom);
  return !finished;
}

Example #2

File: WheelScrollAnimation.cpp Project: LordJZ/gecko-dev

bool
WheelScrollAnimation::DoSample(FrameMetrics& aFrameMetrics, const TimeDuration& aDelta)
{
  TimeStamp now = AsyncPanZoomController::GetFrameTime();
  CSSToParentLayerScale2D zoom = aFrameMetrics.GetZoom();

  // If the animation is finished, make sure the final position is correct by
  // using one last displacement. Otherwise, compute the delta via the timing
  // function as normal.
  bool finished = IsFinished(now);
  nsPoint sampledDest = finished
                        ? mDestination
                        : PositionAt(now);
  ParentLayerPoint displacement =
    (CSSPoint::FromAppUnits(sampledDest) - aFrameMetrics.GetScrollOffset()) * zoom;

  // Note: we ignore overscroll for wheel animations.
  ParentLayerPoint adjustedOffset, overscroll;
  mApzc.mX.AdjustDisplacement(displacement.x, adjustedOffset.x, overscroll.x);
  mApzc.mY.AdjustDisplacement(displacement.y, adjustedOffset.y, overscroll.y,
                              !aFrameMetrics.AllowVerticalScrollWithWheel());

  // If we expected to scroll, but there's no more scroll range on either axis,
  // then end the animation early. Note that the initial displacement could be 0
  // if the compositor ran very quickly (<1ms) after the animation was created.
  // When that happens we want to make sure the animation continues.
  if (!IsZero(displacement) && IsZero(adjustedOffset)) {
    // Nothing more to do - end the animation.
    return false;
  }

  aFrameMetrics.ScrollBy(adjustedOffset / zoom);
  return !finished;
}