protected:
	struct Item : Node {
		union {
			int            parent;
			int            freelink;
		};

		bool           free;
		bool           isopen;
		bool           sel;
		Vector<int>    child;
		int            linei;

		Size GetValueSize(const Display *treedisplay) const;
		Size GetCtrlSize() const;
		Size GetSize(const Display *treedisplay) const;

		Item() { isopen = false; linei = -1; parent = -1; canselect = true; sel = false; free = false; }
	};
	struct Line : Moveable<Line> {
		int  level;
		int  itemi;
		int  ll;
		int  y;
	};
	
	ScrollBars   sb;	
	Scroller     scroller;
	bool         nobg;
	int          levelcx;
	bool         noroot;
	Vector<Line> line;	
	Array<Item>  item;	
	int          dropitem, dropinsert;
	bool         highlight_ctrl;		
	int          cursor;
	bool         nocursor;
	bool         multiselect;
	
	const Display *display;
	
	int    FindLine(int y) const;
	const Display *GetStyle(int i, Color& fg, Color& bg, dword& st);