System.Windows.Forms.TreeView.OnMouseDown C# (CSharp) Method

        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);
            if (_scrollHovered)
            {
                var mclient = PointToClient(MousePosition);

                _scroll = true;
                _scrollStartY = mclient.Y - _scrollbarY;
                return;
            }

            if (_SelectAtPosition(e) != null) NodeMouseClick(this, new TreeNodeMouseClickEventArgs(SelectedNode, e.Button, e.Clicks, e.X, e.Y));

            _dragNode = SelectedNode;
            _drag = true;
            _dragPosition = e.Location;
        }
        protected override void OnMouseHover(EventArgs e)