void Delete(Wrap wrap)
{
foreach (var e in wrap.Subtree.OfType <VideoWrap>())
{
UnassignedVideos.Add(e);
}
}
void Remove()
{
if (SelectedItem is VideoWrap)
{
SelectedItem.Parent.Items.Remove(SelectedItem);
UnassignedVideos.Add(SelectedItem as VideoWrap);
}
else
{
Remove(SelectedItem);
}
}