private IEnumerator <object> HandleDragTask(VelocityMeter velocityMeter, float mouseProjectedPosition, DragGesture dragGesture)
{
if (!CanScroll || !ScrollWhenContentFits && MaxScrollPosition == 0 || ScrollBySlider)
{
yield break;
}
// Do not block scrollview on refresh gesture
IsBeingRefreshed = false;
IsDragging = true;
float realScrollPosition = ScrollPosition;
wheelScrollState = WheelScrollState.Stop;
while (dragGesture.IsChanging())
{
var newMouseProjectedPosition = ProjectToScrollAxisWithFrameRotation(Input.MousePosition);
realScrollPosition += mouseProjectedPosition - newMouseProjectedPosition;
// Round scrolling position to prevent blurring
ScrollPosition = ClampScrollPositionWithinBounceZone(realScrollPosition).Round();
mouseProjectedPosition = newMouseProjectedPosition;
velocityMeter.AddSample(realScrollPosition);
yield return(null);
}
StartScrolling(InertialScrollingTask(velocityMeter.CalcVelocity()));
IsDragging = false;
}
private IEnumerator <object> WheelScrollingTask()
{
const int wheelScrollingSpeedFactor = 8;
wheelScrollState = WheelScrollState.Stop;
float totalScrollAmount = 0f;
while (true)
{
yield return(null);
var IsScrollingByMouseWheel =
!Frame.Input.IsMousePressed() &&
(Frame.Input.WasKeyPressed(Key.MouseWheelDown) || Frame.Input.WasKeyPressed(Key.MouseWheelUp)) && CanScroll;
if (IsScrollingByMouseWheel)
{
var newWheelScrollState = (WheelScrollState)Math.Sign(Frame.Input.WheelScrollAmount);
if (newWheelScrollState != wheelScrollState)
{
totalScrollAmount = 0f;
wheelScrollState = newWheelScrollState;
}
totalScrollAmount -= Frame.Input.WheelScrollAmount;
}
if (totalScrollAmount.Abs() >= 1f && wheelScrollState != WheelScrollState.Stop)
{
StopScrolling();
var stepPerFrame = totalScrollAmount * Task.Current.Delta * wheelScrollingSpeedFactor;
var prevScrollPosition = ScrollPosition;
ScrollPosition = Mathf.Clamp(ScrollPosition + stepPerFrame, MinScrollPosition, MaxScrollPosition);
if (ScrollPosition == MinScrollPosition || ScrollPosition == MaxScrollPosition)
{
totalScrollAmount = 0f;
}
else
{
// If scroll stopped in the middle, we need to round to upper int if we move down
// or to lower int if we move up.
ScrollPosition = stepPerFrame > 0 ? ScrollPosition.Ceiling() : ScrollPosition.Floor();
totalScrollAmount += (prevScrollPosition - ScrollPosition);
}
}
else
{
wheelScrollState = WheelScrollState.Stop;
}
}
}
