SilverlightMappingToolBasic.MapDepth.TreeNodeGroup.GetYPosition C# (CSharp) Method

        public double GetYPosition() 
        {
            double position = 0;
            if (ChildNodes.Count > 1)
            {
                double nodeGroupHeight = GetHeight();
                position = (0.5 * nodeGroupHeight) + ChildNodes[0].Location.Y;
            }
            else if (ChildNodes.Count == 1)
            {
                position = ChildNodes[0].Location.Y;
            }
            return position;
        }

        /// <summary>
        /// Recursively goes through the node tree until it reaches the ends and places the Y coordinate for each node
        /// Each node is moved with relation to nodes above and to the right of it.
        /// </summary>
        public void PositionNodes(TreeNodeGroup nodeGroup, int depth)
        {
            if (nodeGroup.ParentChildGroups.Count == 0) //is a leaf node
            {
                if (!_depthYMargin.ContainsKey(depth))
                {
                    //if you're positioning nodes below nodes that have already been positioned but deeper into the tree
                    //they must be lower than those nodes above, this gets that value and passes it on
                    if (depth > _maxTreeDepth && _depthYMargin.ContainsKey(_maxTreeDepth))
                    {
                        _depthYMargin[depth] = _depthYMargin[_maxTreeDepth];
                        _maxTreeDepth = depth;
                    }
                    else
                    {
                        _depthYMargin[depth] = MarginFromTop;
                        if (depth > _maxTreeDepth)
                        {
                            _maxTreeDepth = depth;
                        }
                    }
                }
                nodeGroup.ParentNode.MoveNode(new Point(nodeGroup.ParentNode.Location.X, _depthYMargin[depth]), true);
                _depthYMargin[depth] += nodeGroup.ParentNode.NodeControl.ActualHeight + VERTICAL_BUFFER;
            }
            else //is a parent node
            {
                bool firstRow = false;
                for (int i = 0; i < nodeGroup.ParentChildGroups.Count; i++)
                {
                    if (!_depthYMargin.ContainsKey(depth))
                    {
                        firstRow = true;
                        _depthYMargin[depth] = nodeGroup.ParentNode.NodeControl.ActualHeight + VERTICAL_BUFFER;
                    }
                    else
                    {
                        firstRow = false;
                    }
                    PositionNodes(nodeGroup.ParentChildGroups[i], depth+1);
                }

                double position = nodeGroup.GetYPosition();

                //if it's not the top most nodes check that it doesn't collide with a row of nodes above it
                if ((position < _depthYMargin[depth] - MarginFromTop) && !firstRow)
                {
                    OffsetNodes(nodeGroup, depth); //collision was detected, move all the nodes from this node to the depth of the tree down
                }
                else
                {
                    nodeGroup.ParentNode.MoveNode(new Point(nodeGroup.ParentNode.Location.X, position), true);
                    _depthYMargin[depth] = position + nodeGroup.ParentNode.NodeControl.ActualHeight + VERTICAL_BUFFER;
                }
            }
        }