bool
WheelBlockState::AllowScrollHandoff() const
{
// If we're in a wheel transaction, we do not allow overscroll handoff until
// a new event ends the wheel transaction.
return !IsTargetConfirmed() || !InTransaction();
}
void
WheelBlockState::Update(const ScrollWheelInput& aEvent)
{
// We might not be in a transaction if the block never started in a
// transaction - for example, if nothing was scrollable.
if (!InTransaction()) {
return;
}
// If we can't scroll in the direction of the wheel event, we don't update
// the last move time. This allows us to timeout a transaction even if the
// mouse isn't moving.
//
// We skip this check if the target is not yet confirmed, so that when it is
// confirmed, we don't timeout the transaction.
nsRefPtr<AsyncPanZoomController> apzc = GetTargetApzc();
if (IsTargetConfirmed() && !apzc->CanScroll(aEvent)) {
return;
}
// Update the time of the last known good event, and reset the mouse move
// time to null. This will reset the delays on both the general transaction
// timeout and the mouse-move-in-frame timeout.
mLastEventTime = aEvent.mTimeStamp;
mLastMouseMove = TimeStamp();
}
bool
CancelableBlockState::IsReadyForHandling() const
{
if (!IsTargetConfirmed())
return false;
return mContentResponded || mContentResponseTimerExpired;
}
void
WheelBlockState::Update(ScrollWheelInput& aEvent)
{
// We might not be in a transaction if the block never started in a
// transaction - for example, if nothing was scrollable.
if (!InTransaction()) {
return;
}
// The current "scroll series" is a like a sub-transaction. It has a separate
// timeout of 80ms. Since we need to compute wheel deltas at different phases
// of a transaction (for example, when it is updated, and later when the
// event action is taken), we affix the scroll series counter to the event.
// This makes GetScrollWheelDelta() consistent.
if (!mLastEventTime.IsNull() &&
(aEvent.mTimeStamp - mLastEventTime).ToMilliseconds() > kScrollSeriesTimeoutMs)
{
mScrollSeriesCounter = 0;
}
aEvent.mScrollSeriesNumber = ++mScrollSeriesCounter;
// If we can't scroll in the direction of the wheel event, we don't update
// the last move time. This allows us to timeout a transaction even if the
// mouse isn't moving.
//
// We skip this check if the target is not yet confirmed, so that when it is
// confirmed, we don't timeout the transaction.
RefPtr<AsyncPanZoomController> apzc = GetTargetApzc();
if (IsTargetConfirmed() && !apzc->CanScroll(aEvent)) {
return;
}
// Update the time of the last known good event, and reset the mouse move
// time to null. This will reset the delays on both the general transaction
// timeout and the mouse-move-in-frame timeout.
mLastEventTime = aEvent.mTimeStamp;
mLastMouseMove = TimeStamp();
}
