private void UpdateViewRange(int scrollStep)
{
LoopInfo target = new LoopInfo
{
Left = scrollStep,
Length = PageStepLen
};
int viewCount = Mathf.Min(ItemCount - target.Left * PageDiv, PageSize);
if (viewCount < 0)
{
viewCount = 0;
}
int deltaSize = viewCount - viewList.Count;
for (int i = 0; i < deltaSize; i++)
{
viewList.Add(null);
}
LoopInfo intersection = target.Clamp(viewRange);
int sstart = 0;
int scount = 0;
if (intersection.Length > 0)
{
sstart = Mathf.Max(0, target.GetOffset(intersection.Left) * PageDiv);
scount = Mathf.Min(intersection.Length * PageDiv, viewCount);
var sdir = target.GetOffset(viewRange.Left) * PageDiv;
MoveItems(viewList, sstart - sdir, scount, sdir);
}
for (int i = 0; i < -deltaSize; i++)
{
DisposeItem(viewList, viewList.Count - 1);
}
int a = sstart;
int b = a + scount - 1;
for (int i = 0; i < viewCount; i++)
{
if (i < a || i > b)
{
UpdateItem(viewList, i, OffsetByPage(target, i));
}
}
viewRange.Left = scrollStep;
viewRange.Length = PageStepLen;
}
