public override int FindTargetSnapPosition(RecyclerView.LayoutManager layoutManager, int velocityX, int velocityY)
{
if (CurrentTargetPosition == -1)
{
CurrentTargetPosition = base.FindTargetSnapPosition(layoutManager, velocityX, velocityY);
return(CurrentTargetPosition);
}
var increment = 1;
if (layoutManager.CanScrollHorizontally())
{
if (velocityX < 0)
{
increment = -1;
}
}
else if (layoutManager.CanScrollVertically())
{
if (velocityY < 0)
{
increment = -1;
}
}
if (IsLayoutReversed(layoutManager))
{
increment = increment * -1;
}
CurrentTargetPosition = CurrentTargetPosition + increment;
return(CurrentTargetPosition);
}
public override int[] CalculateDistanceToFinalSnap(RecyclerView.LayoutManager layoutManager, View targetView)
{
int[] result = new int[2];
result[0] = layoutManager.CanScrollHorizontally()
? DistanceToStart(targetView, GetHorizontalHelper(layoutManager))
: 0;
result[1] = layoutManager.CanScrollVertically()
? DistanceToStart(targetView, GetVerticalHelper(layoutManager))
: 0;
return(result);
}
public override int FindTargetSnapPosition(RecyclerView.LayoutManager layoutManager, int velocityX, int velocityY)
{
var itemCount = layoutManager.ItemCount;
//reset CurrentTargetPosition if ItemCount Changed is requested
//We could be adding a item before the CurrentTargetPosition
if (_previousCount != itemCount)
{
CurrentTargetPosition = -1;
_previousCount = itemCount;
}
if (CurrentTargetPosition == -1)
{
CurrentTargetPosition = base.FindTargetSnapPosition(layoutManager, velocityX, velocityY);
return(CurrentTargetPosition);
}
var increment = 1;
if (layoutManager.CanScrollHorizontally())
{
if (velocityX < 0)
{
increment = -1;
}
}
else if (layoutManager.CanScrollVertically())
{
if (velocityY < 0)
{
increment = -1;
}
}
if (IsLayoutReversed(layoutManager))
{
increment *= -1;
}
if (CurrentTargetPosition == itemCount - 1 && increment == 1)
{
return(CurrentTargetPosition);
}
CurrentTargetPosition = CurrentTargetPosition + increment;
return(CurrentTargetPosition);
}