private void MoveChildren(GeneratorPosition fromPos, GeneratorPosition toPos, int containerCount)
{
if (fromPos == toPos)
return;
Debug.Assert(_itemContainerGenerator != null, "Encountered a null _itemContainerGenerator while receiving an Move action from a generator.");
IItemContainerGenerator generator = (IItemContainerGenerator)_itemContainerGenerator;
int toIndex = generator.IndexFromGeneratorPosition(toPos);
UIElement[] elements = new UIElement[containerCount];
for (int i = 0; i < containerCount; i++)
elements[i] = _uiElementCollection[fromPos.Index + i];
_uiElementCollection.RemoveRangeInternal(fromPos.Index, containerCount);
for (int i = 0; i < containerCount; i++)
{
_uiElementCollection.InsertInternal(toIndex + i, elements[i]);
}
}
// This is internal as an optimization for VirtualizingStackPanel (so it doesn't need to re-query InternalChildren repeatedly)
internal static void RemoveInternalChildRange(UIElementCollection children, int index, int range)
{
children.RemoveRangeInternal(index, range);
}
// This is internal as an optimization for VirtualizingStackPanel (so it doesn't need to re-query InternalChildren repeatedly)
internal static void RemoveInternalChildRange(UIElementCollection children, int index, int range)
{
children.RemoveRangeInternal(index, range);
}