void Remove(Wrap what)
{
if (what.Parent == null) return;
what.Parent.Items.Remove(what);
what.Parent = null;
}
Tuple<Wrap, Wrap> GetWhereAndBeforeOf(Wrap what, Wrap anchor, MoveDestination dst)
{
if (dst == MoveDestination.Into)
{
if (what is VideoWrap && anchor is VideoWrap)
return GetWhereAndBeforeOf(what, anchor, MoveDestination.After);
return new Tuple<Wrap, Wrap>(anchor, null);
}
if (dst == MoveDestination.Before)
{
return Tuple.Create(anchor.Parent, anchor);
}
if (dst == MoveDestination.After)
{
if (anchor.Items.Count == 0)
{
if (anchor.Parent == null) return new Tuple<Wrap, Wrap>(null, null);
var index = anchor.Parent.Items.IndexOf(anchor);
if (index == anchor.Parent.Items.Count - 1)
return new Tuple<Wrap, Wrap>(anchor.Parent, null);
return
Tuple.Create(anchor.Parent, anchor.Parent.Items[index + 1]);
}
return Tuple.Create(anchor, anchor.Items[0]);
}
throw new Exception("Cannot fall here");
}
void Delete(Wrap wrap)
{
foreach (var e in wrap.Subtree.OfType<VideoWrap>()) UnassignedVideos.Add(e);
}
//void MoveTopic(TopicViewModel what, TopicViewModel where, int index)
//{
// //проверяем, что не переносим корень
// if (what.Parent == null) return;
// //проверяем, что не переносим родителя в ребенка
// var parent=where;
// while (true)
// {
// if (what == parent) return;
// parent=parent.Parent;
// if (parent == null) break;
// }
// what.Parent.Items.Remove(what);
// if (index < where.Items.Count)
// where.Items.Insert(index, what);
// else if (index == where.Items.Count)
// where.Items.Add(what);
// else throw new ArgumentException();
// what.Parent = where;
//}
bool CheckMoveConsistancy(Wrap what, Wrap where)
{
//Корень перемещать нельзя
if (what == Root[0]) return false;
//Нельзя перемещать в сына
var parent = where;
while (true)
{
if (parent == null) break;
if (parent == what) return false;
parent = parent.Parent;
}
//Нельзя перемещать в видео
if (where is VideoWrap) return false;
return true;
}
public void MoveToTree(Wrap what, Wrap anchor, MoveDestination dst)
{
var resp = GetWhereAndBeforeOf(what, anchor, dst);
Wrap where = resp.Item1;
Wrap beforeOf = resp.Item2;
if (where == null) return;
if (!CheckMoveConsistancy(what, where)) return;
if (what.Parent!=null)
Remove(what);
if (UnassignedVideos.Contains(what))
UnassignedVideos.Remove(what as VideoWrap);
Insert(what, where, beforeOf);
}
public void Insert(Wrap what, Wrap where, Wrap beforeOf)
{
var index = where.Items.IndexOf(beforeOf);
if (index == -1) index = where.Items.Count;
where.Items.Insert(index, what);
what.Parent = where;
}