Object graph visualizer - fix bug in TreeLayouter.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@4158 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/Misc/Debugger/Debugger.AddIn/Project/Src/Visualizers/Graph/Layout/Tree/TreeLayouter.cs

@@ -83,7 +83,7 @@ namespace Debugger.AddIn.Visualizers.Graph.Layout
 					subtreeSize += newChild.SubtreeSize;
 				}
 			}
-			subtreeSize = Math.Max(newTreeNode.LateralSize + newTreeNode.LateralMargin, subtreeSize);
+			subtreeSize = Math.Max(newTreeNode.LateralSizeWithMargin, subtreeSize);
 			newTreeNode.SubtreeSize = subtreeSize;
 			
 			return newTreeNode;
@@ -97,9 +97,15 @@ namespace Debugger.AddIn.Visualizers.Graph.Layout
 		/// <param name="mainStart"></param>
 		private void calculateNodePosRecursive(TreeNode node, double lateralStart, double mainStart)
 		{
+			double childsSubtreeSize = node.Childs.Sum(child => child.SubtreeSize);
 			// center this node
-			double subtreeSize = node.Childs.Sum(child => child.SubtreeSize);
-			double center = node.ChildEdges.Count() == 0 ? 0 : 0.5 * (subtreeSize - (node.LateralSize + node.LateralMargin));
+			double center = node.ChildEdges.Count() == 0 ? 0 : 0.5 * (childsSubtreeSize - (node.LateralSizeWithMargin));
+			if (center < 0)
+			{
+				// if root is larger than subtree, it would be shifted below lateralStart
+				// -> make whole layout start at lateralStart
+				lateralStart -= center;
+			}
 			
 			// design alternatives
 			// node.MainPos += center;  // used this
@@ -110,7 +116,7 @@ namespace Debugger.AddIn.Visualizers.Graph.Layout
 			node.MainCoord = mainStart;
 			
 			double childLateral = lateralStart;
-			double childsMainFixed = node.MainCoord + node.MainSize + node.MainMargin;
+			double childsMainFixed = node.MainCoord + node.MainSizeWithMargin;
 			foreach (TreeNode child in node.Childs)
 			{
 				calculateNodePosRecursive(child, childLateral, childsMainFixed);

src/AddIns/Misc/Debugger/Debugger.AddIn/Project/Src/Visualizers/Graph/Layout/Tree/TreeNode.cs

@@ -45,6 +45,9 @@ namespace Debugger.AddIn.Visualizers.Graph.Layout
 		public abstract double MainSize { get; }
 		public abstract double LateralSize { get; }
 		
+		public double MainSizeWithMargin { get { return MainSize + MainMargin; } }
+		public double LateralSizeWithMargin { get { return LateralSize + LateralMargin; } }
+		
 		public abstract double MainMargin { get; }
 		public abstract double LateralMargin { get; }