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;
}
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;
}