private void SetCurrent(DataRefBase <T> newItem, int newPosition, int count)
{
if (newItem != null)
{
_isCurrentBeforeFirst = _isCurrentAfterLast = false;
}
else if (count == 0)
{
_isCurrentBeforeFirst = _isCurrentAfterLast = true;
newPosition = -1;
}
else
{
_isCurrentBeforeFirst = newPosition < 0;
_isCurrentAfterLast = newPosition >= count;
}
_currentItem = newItem;
_currentPosition = newPosition;
}
public VirtualListCollectionView(VirtualList <T> list)
: base(list.Cache.NumCacheBlocks, list.Cache.NumItemsPerCacheBlock)
{
_loadFunc = list.Load;
_sourceCollection = list;
_sourceCollection.CollectionChanged += AtSourceCollectionChanged; //EXPERIMENTAL "Add" Support
// initialize current item and markers
if (list.Count == 0)
{
_isCurrentAfterLast = _isCurrentBeforeFirst = true;
}
else
{
_currentPosition = 0;
_currentItem = list[0];
}
_needsRefresh = true;
}
public int IndexOf(DataRefBase <T> item)
{
var dataRef = item as CachedDataRef;
return(dataRef != null && dataRef.List == this ? dataRef.Index : -1);
}
public void Insert(int index, DataRefBase <T> item)
{
throw new NotImplementedException();
}
private void SetCurrent(DataRefBase <T> newItem, int newPosition)
{
int count = newItem != null ? 0 : Count;
SetCurrent(newItem, newPosition, count);
}
