public override void Fill(float contentPos)
{
float psDiff = contentPos + headOffset;
float peDiff = psDiff + currentContentSize - paddedSize;
float psEntryOffset = entry[0].info.size;
float peEntryOffset = entry[entry.Count - 1].info.size;
int totalCount = indexOffset + currentCount;
bool sizeChanged = false;
Entry <T> e = null;
//Debug.Log($"posOffset {contentPosOffset} psDiff {psDiff} ps {psEntryOffset}");
if (totalCount == targetCount && contentPos < 0)
{
//nothing
}
else if (psDiff < 0 && -psDiff >= psEntryOffset + recyclePadding)
{
//Debug.Log($"recycle head psDiff {psDiff} ps {psEntryOffset}");
//recycle head
indexOffset += elementPerLine;
currentCount -= elementPerLine;
for (int r = 0; r < elementPerLine; ++r)
{
SwitchT(entry[r].item, false);
}
entry.RemoveAt(0, elementPerLine);
headOffset += psEntryOffset;
currentContentSize -= psEntryOffset;
}
else if (psDiff > 0 && indexOffset > 0)
{
//Debug.Log($"add head psDiff {psDiff} ps {psEntryOffset}");
//add head
indexOffset -= elementPerLine;
currentCount += elementPerLine;
entry.AddTo(0, elementPerLine);
for (int r = 0; r < elementPerLine; ++r)
{
e = ActivateEntry(entry[r]);
e.info = FillT(indexOffset + r, e.item);
e.transform.anchoredPosition = Repos(r, -e.info.size - currentContentSize);
e.transform.name = (indexOffset + r).ToString();
}
headOffset -= e.info.size;
currentContentSize += e.info.size;
}
if (indexOffset == 0 && contentPos > 0)
{
//nothing
}
else if (peDiff > 0 && peDiff >= peEntryOffset + recyclePadding)
{
//Debug.Log($"recycle tail peDiff {peDiff} pe {peEntryOffset}");
sizeChanged = true;
//recycle tail
for (int r = 0; r < tailCount; ++r)
{
SwitchT((e = entry.RemoveAt(entry.Count - 1)).item, false);
}
//Debug.Log($"recycled {tailCount}");
currentCount -= tailCount;
tailCount = elementPerLine;
currentContentSize -= peEntryOffset;
}
else if (peDiff < 0 && totalCount < targetCount)
{
//Debug.Log($"add tail peDiff {peDiff} pe {peEntryOffset}");
sizeChanged = true;
//add tail
tailCount = Mathf.Min(targetCount - totalCount, elementPerLine);
for (int r = 0; r < tailCount; ++r)
{
e = ActivateEntry(entry.Add());
e.info = FillT(totalCount + r, e.item);
e.transform.anchoredPosition = Repos(r, 0);
e.transform.name = (totalCount + r).ToString();
}
//Debug.Log($"added {tailCount} {totalCount} {targetCount} {e.offset}");
currentCount += tailCount;
currentContentSize += e.info.size;
}
if (sizeChanged)
{
RefreshContentSize();
}
}