ScrollResultOneDimensional ScrollAnimator::userScroll(
ScrollbarOrientation orientation, ScrollGranularity granularity, float step, float delta)
{
if (!m_scrollableArea->scrollAnimatorEnabled())
return ScrollAnimatorBase::userScroll(orientation, granularity, step, delta);
TRACE_EVENT0("blink", "ScrollAnimator::scroll");
if (granularity == ScrollByPrecisePixel)
return ScrollAnimatorBase::userScroll(orientation, granularity, step, delta);
float usedPixelDelta = computeDeltaToConsume(orientation, step * delta);
FloatPoint pixelDelta = (orientation == VerticalScrollbar
? FloatPoint(0, usedPixelDelta) : FloatPoint(usedPixelDelta, 0));
FloatPoint targetPos = desiredTargetPosition();
targetPos.moveBy(pixelDelta);
if (m_animationCurve) {
if ((targetPos - m_targetOffset).isZero()) {
// Report unused delta only if there is no animation running. See
// comment below regarding scroll latching.
return ScrollResultOneDimensional(/* didScroll */ true, /* unusedScrollDelta */ 0);
}
m_targetOffset = targetPos;
ASSERT(m_runState == RunState::RunningOnMainThread
|| m_runState == RunState::RunningOnCompositor
|| m_runState == RunState::RunningOnCompositorButNeedsUpdate);
if (m_runState == RunState::RunningOnCompositor
|| m_runState == RunState::RunningOnCompositorButNeedsUpdate) {
if (registerAndScheduleAnimation())
m_runState = RunState::RunningOnCompositorButNeedsUpdate;
return ScrollResultOneDimensional(/* didScroll */ true, /* unusedScrollDelta */ 0);
}
// Running on the main thread, simply update the target offset instead
// of sending to the compositor.
m_animationCurve->updateTarget(m_timeFunction() - m_startTime, targetPos);
return ScrollResultOneDimensional(/* didScroll */ true, /* unusedScrollDelta */ 0);
}
if ((targetPos - currentPosition()).isZero()) {
// Report unused delta only if there is no animation and we are not
// starting one. This ensures we latch for the duration of the
// animation rather than animating multiple scrollers at the same time.
return ScrollResultOneDimensional(/* didScroll */ false, delta);
}
m_targetOffset = targetPos;
m_startTime = m_timeFunction();
if (registerAndScheduleAnimation())
m_runState = RunState::WaitingToSendToCompositor;
return ScrollResultOneDimensional(/* didScroll */ true, /* unusedScrollDelta */ 0);
}
ScrollResult ScrollAnimatorBase::userScroll(ScrollGranularity,
const ScrollOffset& delta) {
ScrollOffset consumedDelta = computeDeltaToConsume(delta);
ScrollOffset newPos = m_currentOffset + consumedDelta;
if (m_currentOffset == newPos)
return ScrollResult(false, false, delta.width(), delta.height());
m_currentOffset = newPos;
notifyOffsetChanged();
return ScrollResult(consumedDelta.width(), consumedDelta.height(),
delta.width() - consumedDelta.width(),
delta.height() - consumedDelta.height());
}
ScrollResult ScrollAnimatorBase::userScroll(ScrollGranularity, const FloatSize& delta)
{
FloatSize consumedDelta = computeDeltaToConsume(delta);
FloatPoint newPos = m_currentPos + consumedDelta;
if (m_currentPos == newPos)
return ScrollResult(false, false, delta.width(), delta.height());
m_currentPos = newPos;
notifyPositionChanged();
return ScrollResult(
consumedDelta.width(),
consumedDelta.height(),
delta.width() - consumedDelta.width(),
delta.height() - consumedDelta.height());
}
ScrollResult ScrollAnimator::userScroll(ScrollGranularity granularity,
const ScrollOffset& delta) {
if (!m_scrollableArea->scrollAnimatorEnabled())
return ScrollAnimatorBase::userScroll(granularity, delta);
TRACE_EVENT0("blink", "ScrollAnimator::scroll");
if (granularity == ScrollByPrecisePixel) {
// Cancel scroll animation because asked to instant scroll.
if (hasRunningAnimation())
cancelAnimation();
return ScrollAnimatorBase::userScroll(granularity, delta);
}
bool needsPostAnimationCleanup = m_runState == RunState::PostAnimationCleanup;
if (m_runState == RunState::PostAnimationCleanup)
resetAnimationState();
ScrollOffset consumedDelta = computeDeltaToConsume(delta);
ScrollOffset targetOffset = desiredTargetOffset();
targetOffset += consumedDelta;
if (willAnimateToOffset(targetOffset)) {
m_lastGranularity = granularity;
// Report unused delta only if there is no animation running. See
// comment below regarding scroll latching.
// TODO(bokan): Need to standardize how ScrollAnimators report
// unusedDelta. This differs from ScrollAnimatorMac currently.
return ScrollResult(true, true, 0, 0);
}
// If the run state when this method was called was PostAnimationCleanup and
// we're not starting an animation, stay in PostAnimationCleanup state so
// that the main thread scrolling reason can be removed.
if (needsPostAnimationCleanup)
m_runState = RunState::PostAnimationCleanup;
// Report unused delta only if there is no animation and we are not
// starting one. This ensures we latch for the duration of the
// animation rather than animating multiple scrollers at the same time.
return ScrollResult(false, false, delta.width(), delta.height());
}