Add simple XmlReader-based XmlFoldingStrategy to AvalonEdit.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@4912 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/BraceFoldingStrategy.cs

@@ -11,10 +11,31 @@ using System.Collections.Generic;
 
 namespace ICSharpCode.AvalonEdit.Folding
 {
+	/// <summary>
+	/// Base class for folding strategies.
+	/// </summary>
+	public abstract class AbstractFoldingStrategy
+	{
+		/// <summary>
+		/// Create <see cref="NewFolding"/>s for the specified document and updates the folding manager with them.
+		/// </summary>
+		public void UpdateFoldings(FoldingManager manager, TextDocument document)
+		{
+			int firstErrorOffset;
+			IEnumerable<NewFolding> foldings = CreateNewFoldings(document, out firstErrorOffset);
+			manager.UpdateFoldings(foldings, firstErrorOffset);
+		}
+		
+		/// <summary>
+		/// Create <see cref="NewFolding"/>s for the specified document.
+		/// </summary>
+		public abstract IEnumerable<NewFolding> CreateNewFoldings(TextDocument document, out int firstErrorOffset);
+	}
+	
 	/// <summary>
 	/// Allows producing foldings from a document based on braces.
 	/// </summary>
-	public class BraceFoldingStrategy
+	public class BraceFoldingStrategy : AbstractFoldingStrategy
 	{
 		/// <summary>
 		/// Gets/Sets the opening brace. The default value is '{'.
@@ -35,6 +56,15 @@ namespace ICSharpCode.AvalonEdit.Folding
 			this.ClosingBrace = '}';
 		}
 		
+		/// <summary>
+		/// Create <see cref="NewFolding"/>s for the specified document.
+		/// </summary>
+		public override IEnumerable<NewFolding> CreateNewFoldings(TextDocument document, out int firstErrorOffset)
+		{
+			firstErrorOffset = -1;
+			return CreateNewFoldings(document);
+		}
+		
 		/// <summary>
 		/// Create <see cref="NewFolding"/>s for the specified document.
 		/// </summary>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/NewFolding.cs

@@ -21,17 +21,17 @@ namespace ICSharpCode.AvalonEdit.Folding
 	/// <summary>
 	/// Helper class used for <see cref="FoldingManager.UpdateFoldings"/>.
 	/// </summary>
-	public sealed class NewFolding : ISegment
+	public class NewFolding : ISegment
 	{
 		/// <summary>
-		/// Gets the start offset.
+		/// Gets/Sets the start offset.
 		/// </summary>
-		public int StartOffset { get; private set; }
+		public int StartOffset { get; set; }
 		
 		/// <summary>
-		/// Gets the end offset.
+		/// Gets/Sets the end offset.
 		/// </summary>
-		public int EndOffset { get; private set; }
+		public int EndOffset { get; set; }
 		
 		/// <summary>
 		/// Gets/Sets the name displayed for the folding.
@@ -43,6 +43,13 @@ namespace ICSharpCode.AvalonEdit.Folding
 		/// </summary>
 		public bool DefaultClosed { get; set; }
 		
+		/// <summary>
+		/// Creates a new NewFolding instance.
+		/// </summary>
+		public NewFolding()
+		{
+		}
+		
 		/// <summary>
 		/// Creates a new NewFolding instance.
 		/// </summary>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/XmlFoldingStrategy.cs

@@ -0,0 +1,216 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Daniel Grunwald"/>
+//     <version>$Revision$</version>
+// </file>
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Xml;
+
+using ICSharpCode.AvalonEdit.Document;
+
+namespace ICSharpCode.AvalonEdit.Folding
+{
+	/// <summary>
+	/// Holds information about the start of a fold in an xml string.
+	/// </summary>
+	sealed class XmlFoldStart : NewFolding
+	{
+		internal int StartLine;
+	}
+	
+	/// <summary>
+	/// Determines folds for an xml string in the editor.
+	/// </summary>
+	public class XmlFoldingStrategy : AbstractFoldingStrategy
+	{
+		/// <summary>
+		/// Flag indicating whether attributes should be displayed on folded
+		/// elements.
+		/// </summary>
+		public bool ShowAttributesWhenFolded { get; set; }
+		
+		/// <summary>
+		/// Create <see cref="NewFolding"/>s for the specified document.
+		/// </summary>
+		public override IEnumerable<NewFolding> CreateNewFoldings(TextDocument document, out int firstErrorOffset)
+		{
+			try {
+				XmlTextReader reader = new XmlTextReader(document.CreateReader());
+				reader.XmlResolver = null; // don't resolve DTDs
+				return CreateNewFoldings(document, reader, out firstErrorOffset);
+			} catch (XmlException) {
+				firstErrorOffset = 0;
+				return Enumerable.Empty<NewFolding>();
+			}
+		}
+		
+		/// <summary>
+		/// Create <see cref="NewFolding"/>s for the specified document.
+		/// </summary>
+		public IEnumerable<NewFolding> CreateNewFoldings(TextDocument document, XmlReader reader, out int firstErrorOffset)
+		{
+			Stack<XmlFoldStart> stack = new Stack<XmlFoldStart>();
+			List<NewFolding> foldMarkers = new List<NewFolding>();
+			try {
+				while (reader.Read()) {
+					switch (reader.NodeType) {
+						case XmlNodeType.Element:
+							if (!reader.IsEmptyElement) {
+								XmlFoldStart newFoldStart = CreateElementFoldStart(document, reader);
+								stack.Push(newFoldStart);
+							}
+							break;
+							
+						case XmlNodeType.EndElement:
+							XmlFoldStart foldStart = stack.Pop();
+							CreateElementFold(document, foldMarkers, reader, foldStart);
+							break;
+							
+						case XmlNodeType.Comment:
+							CreateCommentFold(document, foldMarkers, reader);
+							break;
+					}
+				}
+				firstErrorOffset = -1;
+			} catch (XmlException ex) {
+				// ignore errors
+				firstErrorOffset = document.GetOffset(ex.LineNumber, ex.LinePosition);
+			}
+			foldMarkers.Sort((a,b) => a.StartOffset.CompareTo(b.StartOffset));
+			return foldMarkers;
+		}
+		
+		int GetOffset(TextDocument document, XmlReader reader)
+		{
+			IXmlLineInfo info = reader as IXmlLineInfo;
+			if (info != null && info.HasLineInfo()) {
+				return document.GetOffset(info.LineNumber, info.LinePosition);
+			} else {
+				throw new ArgumentException("XmlReader does not have positioning information.");
+			}
+		}
+		
+		/// <summary>
+		/// Creates a comment fold if the comment spans more than one line.
+		/// </summary>
+		/// <remarks>The text displayed when the comment is folded is the first
+		/// line of the comment.</remarks>
+		void CreateCommentFold(TextDocument document, List<NewFolding> foldMarkers, XmlReader reader)
+		{
+			string comment = reader.Value;
+			if (comment != null) {
+				int firstNewLine = comment.IndexOf('\n');
+				if (firstNewLine >= 0) {
+					
+					// Take off 4 chars to get the actual comment start (takes
+					// into account the <!-- chars.
+					
+					int startOffset = GetOffset(document, reader) - 4;
+					int endOffset = startOffset + comment.Length + 3;
+					
+					string foldText = String.Concat("<!--", comment.Substring(0, firstNewLine).TrimEnd('\r') , "-->");
+					foldMarkers.Add(new NewFolding(startOffset, endOffset) { Name = foldText } );
+				}
+			}
+		}
+		
+		/// <summary>
+		/// Creates an XmlFoldStart for the start tag of an element.
+		/// </summary>
+		XmlFoldStart CreateElementFoldStart(TextDocument document, XmlReader reader)
+		{
+			// Take off 1 from the offset returned
+			// from the xml since it points to the start
+			// of the element name and not the beginning
+			// tag.
+			//XmlFoldStart newFoldStart = new XmlFoldStart(reader.Prefix, reader.LocalName, reader.LineNumber - 1, reader.LinePosition - 2);
+			XmlFoldStart newFoldStart = new XmlFoldStart();
+			
+			IXmlLineInfo lineInfo = (IXmlLineInfo)reader;
+			newFoldStart.StartLine = lineInfo.LineNumber;
+			newFoldStart.StartOffset = document.GetOffset(newFoldStart.StartLine, lineInfo.LinePosition - 1);
+			
+			if (this.ShowAttributesWhenFolded && reader.HasAttributes) {
+				newFoldStart.Name = String.Concat("<", reader.Name, " ", GetAttributeFoldText(reader), ">");
+			} else {
+				newFoldStart.Name = String.Concat("<", reader.Name, ">");
+			}
+			
+			return newFoldStart;
+		}
+		
+		/// <summary>
+		/// Create an element fold if the start and end tag are on
+		/// different lines.
+		/// </summary>
+		void CreateElementFold(TextDocument document, List<NewFolding> foldMarkers, XmlReader reader, XmlFoldStart foldStart)
+		{
+			IXmlLineInfo lineInfo = (IXmlLineInfo)reader;
+			int endLine = lineInfo.LineNumber;
+			if (endLine > foldStart.StartLine) {
+				int endCol = lineInfo.LinePosition + reader.Name.Length + 1;
+				foldStart.EndOffset = document.GetOffset(endLine, endCol);
+				foldMarkers.Add(foldStart);
+			}
+		}
+		
+		/// <summary>
+		/// Gets the element's attributes as a string on one line that will
+		/// be displayed when the element is folded.
+		/// </summary>
+		/// <remarks>
+		/// Currently this puts all attributes from an element on the same
+		/// line of the start tag.  It does not cater for elements where attributes
+		/// are not on the same line as the start tag.
+		/// </remarks>
+		string GetAttributeFoldText(XmlReader reader)
+		{
+			StringBuilder text = new StringBuilder();
+			
+			for (int i = 0; i < reader.AttributeCount; ++i) {
+				reader.MoveToAttribute(i);
+				
+				text.Append(reader.Name);
+				text.Append("=");
+				text.Append(reader.QuoteChar.ToString());
+				text.Append(XmlEncodeAttributeValue(reader.Value, reader.QuoteChar));
+				text.Append(reader.QuoteChar.ToString());
+				
+				// Append a space if this is not the
+				// last attribute.
+				if (i < reader.AttributeCount - 1) {
+					text.Append(" ");
+				}
+			}
+			
+			return text.ToString();
+		}
+		
+		/// <summary>
+		/// Xml encode the attribute string since the string returned from
+		/// the XmlTextReader is the plain unencoded string and .NET
+		/// does not provide us with an xml encode method.
+		/// </summary>
+		static string XmlEncodeAttributeValue(string attributeValue, char quoteChar)
+		{
+			StringBuilder encodedValue = new StringBuilder(attributeValue);
+			
+			encodedValue.Replace("&", "&amp;");
+			encodedValue.Replace("<", "&lt;");
+			encodedValue.Replace(">", "&gt;");
+			
+			if (quoteChar == '"') {
+				encodedValue.Replace("\"", "&quot;");
+			} else {
+				encodedValue.Replace("'", "&apos;");
+			}
+			
+			return encodedValue.ToString();
+		}
+	}
+}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/ICSharpCode.AvalonEdit.csproj

@@ -172,6 +172,7 @@
       <DependentUpon>IReadOnlySectionProvider.cs</DependentUpon>
     </Compile>
     <Compile Include="Folding\NewFolding.cs" />
+    <Compile Include="Folding\XmlFoldingStrategy.cs" />
     <Compile Include="Highlighting\DocumentHighlighter.cs" />
     <Compile Include="Highlighting\HighlightedInlineBuilder.cs" />
     <Compile Include="Highlighting\HighlightedLine.cs" />