C# Rendering.HeightTreeNode类代码示例

		/// <summary>
		/// Rebuild the tree, in O(n).
		/// </summary>
		public void RebuildDocument()
		{
			foreach (CollapsedLineSection s in GetAllCollapsedSections()) {
				s.Start = null;
				s.End = null;
			}
			
			HeightTreeNode[] nodes = new HeightTreeNode[document.LineCount];
			int lineNumber = 0;
			foreach (DocumentLine ls in document.Lines) {
				nodes[lineNumber++] = new HeightTreeNode(ls, DefaultLineHeight);
			}
			Debug.Assert(nodes.Length > 0);
			// now build the corresponding balanced tree
			int height = DocumentLineTree.GetTreeHeight(nodes.Length);
			Debug.WriteLine("HeightTree will have height: " + height);
			root = BuildTree(nodes, 0, nodes.Length, height);
			root.color = BLACK;
			#if DEBUG
			CheckProperties();
			#endif
		}

		void CheckProperties(HeightTreeNode node)
		{
			int totalCount = 1;
			double totalHeight = node.lineNode.TotalHeight;
			if (node.lineNode.IsDirectlyCollapsed)
				Debug.Assert(node.lineNode.collapsedSections.Count > 0);
			if (node.left != null) {
				CheckProperties(node.left);
				totalCount += node.left.totalCount;
				totalHeight += node.left.totalHeight;
				
				CheckAllContainedIn(node.left.collapsedSections, node.lineNode.collapsedSections);
			}
			if (node.right != null) {
				CheckProperties(node.right);
				totalCount += node.right.totalCount;
				totalHeight += node.right.totalHeight;
				
				CheckAllContainedIn(node.right.collapsedSections, node.lineNode.collapsedSections);
			}
			if (node.left != null && node.right != null) {
				if (node.left.collapsedSections != null && node.right.collapsedSections != null) {
					var intersection = System.Linq.Enumerable.Intersect(node.left.collapsedSections, node.right.collapsedSections);
					Debug.Assert(System.Linq.Enumerable.Count(intersection) == 0);
				}
			}
			if (node.IsDirectlyCollapsed) {
				Debug.Assert(node.collapsedSections.Count > 0);
				totalHeight = 0;
			}
			Debug.Assert(node.totalCount == totalCount);
			Debug.Assert(node.totalHeight.IsClose(totalHeight));
		}

		static bool GetColor(HeightTreeNode node)
		{
			return node != null ? node.color : BLACK;
		}

		static HeightTreeNode Sibling(HeightTreeNode node)
		{
			if (node == node.parent.left)
				return node.parent.right;
			else
				return node.parent.left;
		}

		void ReplaceNode(HeightTreeNode replacedNode, HeightTreeNode newNode)
		{
			if (replacedNode.parent == null) {
				Debug.Assert(replacedNode == root);
				root = newNode;
			} else {
				if (replacedNode.parent.left == replacedNode)
					replacedNode.parent.left = newNode;
				else
					replacedNode.parent.right = newNode;
			}
			if (newNode != null) {
				newNode.parent = replacedNode.parent;
			}
			replacedNode.parent = null;
		}

		void RemoveNode(HeightTreeNode removedNode)
		{
			if (removedNode.left != null && removedNode.right != null) {
				// replace removedNode with it's in-order successor
				
				HeightTreeNode leftMost = removedNode.right.LeftMost;
				HeightTreeNode parentOfLeftMost = leftMost.parent;
				RemoveNode(leftMost); // remove leftMost from its current location
				
				BeforeNodeReplace(removedNode, leftMost, parentOfLeftMost);
				// and overwrite the removedNode with it
				ReplaceNode(removedNode, leftMost);
				leftMost.left = removedNode.left;
				if (leftMost.left != null) leftMost.left.parent = leftMost;
				leftMost.right = removedNode.right;
				if (leftMost.right != null) leftMost.right.parent = leftMost;
				leftMost.color = removedNode.color;
				
				UpdateAfterChildrenChange(leftMost);
				if (leftMost.parent != null) UpdateAfterChildrenChange(leftMost.parent);
				return;
			}
			
			// now either removedNode.left or removedNode.right is null
			// get the remaining child
			HeightTreeNode parentNode = removedNode.parent;
			HeightTreeNode childNode = removedNode.left ?? removedNode.right;
			BeforeNodeRemove(removedNode);
			ReplaceNode(removedNode, childNode);
			if (parentNode != null) UpdateAfterChildrenChange(parentNode);
			if (removedNode.color == BLACK) {
				if (childNode != null && childNode.color == RED) {
					childNode.color = BLACK;
				} else {
					FixTreeOnDelete(childNode, parentNode);
				}
			}
		}

		void InsertAsRight(HeightTreeNode parentNode, HeightTreeNode newNode)
		{
			Debug.Assert(parentNode.right == null);
			parentNode.right = newNode;
			newNode.parent = parentNode;
			newNode.color = RED;
			UpdateAfterChildrenChange(parentNode);
			FixTreeOnInsert(newNode);
		}

		static void UpdateAugmentedData(HeightTreeNode node, UpdateAfterChildrenChangeRecursionMode mode)
		{
			int totalCount = 1;
			double totalHeight = node.lineNode.TotalHeight;
			if (node.left != null) {
				totalCount += node.left.totalCount;
				totalHeight += node.left.totalHeight;
			}
			if (node.right != null) {
				totalCount += node.right.totalCount;
				totalHeight += node.right.totalHeight;
			}
			if (node.IsDirectlyCollapsed)
				totalHeight = 0;
			if (totalCount != node.totalCount
			    || !totalHeight.IsClose(node.totalHeight)
			    || mode == UpdateAfterChildrenChangeRecursionMode.WholeBranch)
			{
				node.totalCount = totalCount;
				node.totalHeight = totalHeight;
				if (node.parent != null && mode != UpdateAfterChildrenChangeRecursionMode.None)
					UpdateAugmentedData(node.parent, mode);
			}
		}

		static void UpdateAfterChildrenChange(HeightTreeNode node)
		{
			UpdateAugmentedData(node, UpdateAfterChildrenChangeRecursionMode.IfRequired);
		}

		HeightTreeNode InsertAfter(HeightTreeNode node, DocumentLine newLine)
		{
			HeightTreeNode newNode = new HeightTreeNode(newLine, defaultLineHeight);
			if (node.right == null) {
				if (node.lineNode.collapsedSections != null) {
					// we are inserting directly after node - so copy all collapsedSections
					// that do not end at node.
					foreach (CollapsedLineSection cs in node.lineNode.collapsedSections) {
						if (cs.End != node.documentLine)
							newNode.AddDirectlyCollapsed(cs);
					}
				}
				InsertAsRight(node, newNode);
			} else {
				node = node.right.LeftMost;
				if (node.lineNode.collapsedSections != null) {
					// we are inserting directly before node - so copy all collapsedSections
					// that do not start at node.
					foreach (CollapsedLineSection cs in node.lineNode.collapsedSections) {
						if (cs.Start != node.documentLine)
							newNode.AddDirectlyCollapsed(cs);
					}
				}
				InsertAsLeft(node, newNode);
			}
			return newNode;
		}

		/// <summary>
		/// build a tree from a list of nodes
		/// </summary>
		HeightTreeNode BuildTree(HeightTreeNode[] nodes, int start, int end, int subtreeHeight)
		{
			Debug.Assert(start <= end);
			if (start == end) {
				return null;
			}
			int middle = (start + end) / 2;
			HeightTreeNode node = nodes[middle];
			node.left = BuildTree(nodes, start, middle, subtreeHeight - 1);
			node.right = BuildTree(nodes, middle + 1, end, subtreeHeight - 1);
			if (node.left != null) node.left.parent = node;
			if (node.right != null) node.right.parent = node;
			if (subtreeHeight == 1)
				node.color = RED;
			UpdateAugmentedData(node, UpdateAfterChildrenChangeRecursionMode.None);
			return node;
		}

		static void AddRemoveCollapsedSectionDown(CollapsedLineSection section, HeightTreeNode node, int sectionLength, bool add)
		{
			while (true) {
				if (node.left != null) {
					if (node.left.totalCount < sectionLength) {
						// mark left subtree
						if (add)
							node.left.AddDirectlyCollapsed(section);
						else
							node.left.RemoveDirectlyCollapsed(section);
						sectionLength -= node.left.totalCount;
					} else {
						// mark only inside the left subtree
						node = node.left;
						Debug.Assert(node != null);
						continue;
					}
				}
				if (add)
					node.lineNode.AddDirectlyCollapsed(section);
				else
					node.lineNode.RemoveDirectlyCollapsed(section);
				sectionLength -= 1;
				if (sectionLength == 0) {
					// done!
					Debug.Assert(node.documentLine == section.End);
					break;
				}
				// mark inside right subtree:
				node = node.right;
				Debug.Assert(node != null);
			}
		}

		static bool GetIsCollapedFromNode(HeightTreeNode node)
		{
			while (node != null) {
				if (node.IsDirectlyCollapsed)
					return true;
				node = node.parent;
			}
			return false;
		}

		/*
		1. A node is either red or black.
		2. The root is black.
		3. All leaves are black. (The leaves are the NIL children.)
		4. Both children of every red node are black. (So every red node must have a black parent.)
		5. Every simple path from a node to a descendant leaf contains the same number of black nodes. (Not counting the leaf node.)
		 */
		void CheckNodeProperties(HeightTreeNode node, HeightTreeNode parentNode, bool parentColor, int blackCount, ref int expectedBlackCount)
		{
			if (node == null) return;
			
			Debug.Assert(node.parent == parentNode);
			
			if (parentColor == RED) {
				Debug.Assert(node.color == BLACK);
			}
			if (node.color == BLACK) {
				blackCount++;
			}
			if (node.left == null && node.right == null) {
				// node is a leaf node:
				if (expectedBlackCount == -1)
					expectedBlackCount = blackCount;
				else
					Debug.Assert(expectedBlackCount == blackCount);
			}
			CheckNodeProperties(node.left, node, node.color, blackCount, ref expectedBlackCount);
			CheckNodeProperties(node.right, node, node.color, blackCount, ref expectedBlackCount);
		}

		static void AppendTreeToString(HeightTreeNode node, StringBuilder b, int indent)
		{
			if (node.color == RED)
				b.Append("RED   ");
			else
				b.Append("BLACK ");
			b.AppendLine(node.ToString());
			indent += 2;
			if (node.left != null) {
				b.Append(' ', indent);
				b.Append("L: ");
				AppendTreeToString(node.left, b, indent);
			}
			if (node.right != null) {
				b.Append(' ', indent);
				b.Append("R: ");
				AppendTreeToString(node.right, b, indent);
			}
		}