private static void CenterNodesBetween(TreeNodeModel <T> leftNode, TreeNodeModel <T> rightNode)
{
var leftIndex = leftNode.Parent.Children.IndexOf(rightNode);
var rightIndex = leftNode.Parent.Children.IndexOf(leftNode);
var numNodesBetween = rightIndex - leftIndex - 1;
if (numNodesBetween > 0)
{
var distanceBetweenNodes = (leftNode.X - rightNode.X) / (numNodesBetween + 1);
var count = 1;
for (var i = leftIndex + 1; i < rightIndex; i++)
{
var middleNode = leftNode.Parent.Children[i];
var desiredX = rightNode.X + (distanceBetweenNodes * count);
var offset = desiredX - middleNode.X;
middleNode.X += offset;
middleNode.Mod += offset;
count++;
}
CheckForConflicts(leftNode);
}
}
private static void CalculateInitialX(TreeNodeModel <T> node)
{
foreach (var child in node.Children)
{
CalculateInitialX(child);
}
// if no children
if (node.IsLeaf())
{
// if there is a previous sibling in this set, set X to previous sibling + designated distance
if (!node.IsLeftMost())
{
node.X = node.GetPreviousSibling().X + NodeSize + SiblingDistance;
}
else
{
// if this is the first node in a set, set X to 0
node.X = 0;
}
}
// if there is only one child
else if (node.Children.Count == 1)
{
// if this is the first node in a set, set it's X value equal to it's child's X value
if (node.IsLeftMost())
{
node.X = node.Children[0].X;
}
else
{
node.X = node.GetPreviousSibling().X + NodeSize + SiblingDistance;
node.Mod = node.X - node.Children[0].X;
}
}
else
{
var leftChild = node.GetLeftMostChild();
var rightChild = node.GetRightMostChild();
var mid = (leftChild.X + rightChild.X) / 2;
if (node.IsLeftMost())
{
node.X = mid;
}
else
{
node.X = node.GetPreviousSibling().X + NodeSize + SiblingDistance;
node.Mod = node.X - mid;
}
}
if (node.Children.Count > 0 && !node.IsLeftMost())
{
// Since subtrees can overlap, check for conflicts and shift tree right if needed
CheckForConflicts(node);
}
}
// converts list of sample items to hierarchical list of TreeNodeModels
private static TreeNodeModel <NodeModel> GetSampleTree(List <NodeModel> data)
{
var root = data.FirstOrDefault(p => p.ParentId == string.Empty);
var rootTreeNode = new TreeNodeModel <NodeModel>(root, null);
// add tree node children recursively
rootTreeNode.Children = GetChildNodes(data, rootTreeNode);
return(rootTreeNode);
}
// recursively initialize x, y, and mod values of nodes
private static void InitializeNodes(TreeNodeModel <T> node, int depth)
{
node.X = -1;
node.Y = depth;
node.Mod = 0;
foreach (var child in node.Children)
{
InitializeNodes(child, depth + 1);
}
}
private static Size GetSize(TreeNodeModel <NodeModel> tree)
{
// tree sizes are 0-based, so add 1
var treeWidth = tree.Width + 1;
var treeHeight = tree.Height + 1;
var size = new Size(Convert.ToInt32(treeWidth * NodeWidth + (treeWidth + 1) * NodeMarginX),
treeHeight * NodeHeight + (treeHeight + 1) * NodeMarginY);
return(size);
}
public static void CalculateNodePositions(TreeNodeModel <T> rootNode)
{
// initialize node x, y, and mod values
InitializeNodes(rootNode, 0);
// assign initial X and Mod values for nodes
CalculateInitialX(rootNode);
// ensure no node is being drawn off screen
CheckAllChildrenOnScreen(rootNode);
// assign final X values to nodes
CalculateFinalPositions(rootNode, 0);
}
private static List <TreeNodeModel <NodeModel> > GetChildNodes(List <NodeModel> data,
TreeNodeModel <NodeModel> parent)
{
var nodes = new List <TreeNodeModel <NodeModel> >();
foreach (var item in data.Where(p => p.ParentId == parent.Item.Id))
{
var treeNode = new TreeNodeModel <NodeModel>(item, parent);
treeNode.Children = GetChildNodes(data, treeNode);
nodes.Add(treeNode);
}
return(nodes);
}
private static void GetRightContour(TreeNodeModel <T> node, float modSum, ref Dictionary <int, float> values)
{
if (!values.ContainsKey(node.Y))
{
values.Add(node.Y, node.X + modSum);
}
else
{
values[node.Y] = Math.Max(values[node.Y], node.X + modSum);
}
modSum += node.Mod;
foreach (var child in node.Children)
{
GetRightContour(child, modSum, ref values);
}
}
private static void CalculateFinalPositions(TreeNodeModel <T> node, float modSum)
{
node.X += modSum;
modSum += node.Mod;
foreach (var child in node.Children)
{
CalculateFinalPositions(child, modSum);
}
if (node.Children.Count == 0)
{
node.Width = node.X;
node.Height = node.Y;
}
else
{
node.Width = node.Children.OrderByDescending(p => p.Width).First().Width;
node.Height = node.Children.OrderByDescending(p => p.Height).First().Height;
}
}
private static void CheckForConflicts(TreeNodeModel <T> node)
{
const float minDistance = TreeDistance + NodeSize;
var shiftValue = 0F;
var nodeContour = new Dictionary <int, float>();
GetLeftContour(node, 0, ref nodeContour);
var sibling = node.GetLeftMostSibling();
while (sibling != null && sibling != node)
{
var siblingContour = new Dictionary <int, float>();
GetRightContour(sibling, 0, ref siblingContour);
for (var level = node.Y + 1;
level <= Math.Min(siblingContour.Keys.Max(), nodeContour.Keys.Max());
level++)
{
var distance = nodeContour[level] - siblingContour[level];
if (distance + shiftValue < minDistance)
{
shiftValue = minDistance - distance;
}
}
if (shiftValue > 0)
{
node.X += shiftValue;
node.Mod += shiftValue;
CenterNodesBetween(node, sibling);
shiftValue = 0;
}
sibling = sibling.GetNextSibling();
}
}
private static void CheckAllChildrenOnScreen(TreeNodeModel <T> node)
{
var nodeContour = new Dictionary <int, float>();
GetLeftContour(node, 0, ref nodeContour);
float shiftAmount = 0;
foreach (var y in nodeContour.Keys)
{
if (nodeContour[y] + shiftAmount < 0)
{
shiftAmount = nodeContour[y] * -1;
}
}
if (shiftAmount > 0)
{
node.X += shiftAmount;
node.Mod += shiftAmount;
}
}
public TreeNodeModel(T item, TreeNodeModel <T> parent)
{
Item = item;
Parent = parent;
Children = new List <TreeNodeModel <T> >();
}
private static void DrawNode(TreeNodeModel <NodeModel> node, Graphics graphic)
{
// Set the pen
var nodePen = node.Item.Colour;
// rectangle where node will be positioned
var nodeRect = new Rectangle(Convert.ToInt32(NodeMarginX + node.X * (NodeWidth + NodeMarginX)),
NodeMarginY + node.Y * (NodeHeight + NodeMarginY), NodeWidth, NodeHeight);
// draw box
if (!node.Item.IsCompressed)
{
graphic.DrawRectangle(nodePen, nodeRect);
}
// draw content
var font = new Font(FontFamily.GenericMonospace, 8);
var stringSize = graphic.MeasureString(node.ToString(), font);
graphic.DrawString(node.ToString(), font, nodePen.Brush, nodeRect.X + NodeWidth / 2 - stringSize.Width / 2,
nodeRect.Y + NodeHeight / 2 - stringSize.Height / 2);
// draw line to parent
if (node.Parent != null)
{
var nodeTopMiddle = new Point(nodeRect.X + nodeRect.Width / 2, nodeRect.Y);
var nodeBottomMiddle = new Point(nodeTopMiddle.X, nodeTopMiddle.Y - NodeMarginY / 2);
graphic.DrawLine(nodePen, nodeTopMiddle, nodeBottomMiddle);
}
// draw line to children
if (node.Children.Count > 0)
{
var nodeBottomMiddle = new Point(nodeRect.X + nodeRect.Width / 2, nodeRect.Y + nodeRect.Height);
var nodeTopMiddle = new Point(nodeBottomMiddle.X, nodeBottomMiddle.Y + NodeMarginY / 2);
graphic.DrawLine(nodePen, nodeBottomMiddle, nodeTopMiddle);
// draw line over children
if (node.Children.Count > 1)
{
var childrenLineStartX = Convert.ToInt32(NodeMarginX + node.GetRightMostChild().X *
// ReSharper disable once PossibleLossOfFraction
(NodeWidth + NodeMarginX) + NodeWidth / 2);
var childrenLineStartY = nodeBottomMiddle.Y + NodeMarginY / 2;
var childrenLineStart = new Point(childrenLineStartX, childrenLineStartY);
var childrenLineEndX = Convert.ToInt32(NodeMarginX +
node.GetLeftMostChild().X *(NodeWidth + NodeMarginX) +
// ReSharper disable once PossibleLossOfFraction
NodeWidth / 2);
var childrenLineEndY = nodeBottomMiddle.Y + NodeMarginY / 2;
var childrenLineEnd = new Point(childrenLineEndX, childrenLineEndY);
graphic.DrawLine(Pens.Black, childrenLineStart, childrenLineEnd);
}
}
foreach (var item in node.Children)
{
DrawNode(item, graphic);
}
}
private static void PaintTree(Graphics graphic, TreeNodeModel <NodeModel> tree)
{
graphic.Clear(Color.White);
DrawNode(tree, graphic);
}