Improve the code completion triggering logic.

src/AddIns/BackendBindings/CSharpBinding/Project/Src/Completion/CSharpCompletionBinding.cs

@@ -2,7 +2,9 @@
 // This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
 using System;
+using System.Collections.Generic;
 using System.Linq;
+
 using CSharpBinding.Parser;
 using ICSharpCode.NRefactory.Completion;
 using ICSharpCode.NRefactory.CSharp.Completion;
@@ -22,6 +24,18 @@ namespace CSharpBinding.Completion
 		}
 		
 		public bool HandleKeyPressed(ITextEditor editor, char ch)
+		{
+			if (editor.ActiveCompletionWindow != null)
+				return false;
+			return ShowCompletion(editor, ch, false);
+		}
+		
+		public bool CtrlSpace(ITextEditor editor)
+		{
+			return ShowCompletion(editor, '\0', true);
+		}
+		
+		bool ShowCompletion(ITextEditor editor, char completionChar, bool ctrlSpace)
 		{
 			// Don't require the very latest parse information, an older cached version is OK.
 			var parseInfo = ParserService.GetCachedParseInformation(editor.FileName) as CSharpFullParseInformation;
@@ -43,30 +57,45 @@ namespace CSharpBinding.Completion
 				parseInfo.CompilationUnit,
 				parseInfo.ParsedFile
 			);
+			
 			//cc.FormattingPolicy = ?
 			cc.EolMarker = DocumentUtilitites.GetLineTerminator(editor.Document, editor.Caret.Line);
 			//cc.IndentString = ?
-			DefaultCompletionItemList list = new DefaultCompletionItemList();
 			
-			if (char.IsLetterOrDigit (ch) || ch == '_') {
-				//if (completionContext.TriggerOffset > 1 && char.IsLetterOrDigit (document.Editor.GetCharAt (completionContext.TriggerOffset - 2)))
-				//	return null;
-				list.PreselectionLength = 1;
+			int startPos, triggerWordLength;
+			IEnumerable<ICompletionData> completionData;
+			if (ctrlSpace) {
+				if (!cc.TryGetCompletionWord(editor.Caret.Offset, out startPos, out triggerWordLength)) {
+					startPos = editor.Caret.Offset;
+					triggerWordLength = 0;
+				}
+				completionData = cc.GetCompletionData(startPos, true);
+			} else {
+				startPos = editor.Caret.Offset;
+				if (char.IsLetterOrDigit (completionChar) || completionChar == '_') {
+					if (startPos > 1 && char.IsLetterOrDigit (editor.Document.GetCharAt (startPos - 2)))
+						return false;
+					completionData = cc.GetCompletionData(startPos, false);
+					startPos--;
+					triggerWordLength = 1;
+				} else {
+					completionData = cc.GetCompletionData(startPos, false);
+					triggerWordLength = 0;
+				}
 			}
-			list.Items.AddRange(cc.GetCompletionData(editor.Caret.Offset, false).Cast<ICompletionItem>());
+			
+			DefaultCompletionItemList list = new DefaultCompletionItemList();
+			list.Items.AddRange(completionData.Cast<ICompletionItem>());
 			if (list.Items.Count > 0) {
 				list.SortItems();
+				list.PreselectionLength = editor.Caret.Offset - startPos;
+				list.PostselectionLength = Math.Max(0, startPos + triggerWordLength - editor.Caret.Offset);
 				list.SuggestedItem = list.Items.FirstOrDefault(i => i.Text == cc.DefaultCompletionString);
 				editor.ShowCompletionWindow(list);
 				return true;
 			}
 			return false;
 		}
-		
-		public bool CtrlSpace(ITextEditor editor)
-		{
-			return false;
-		}
 	}
 }
 

src/AddIns/BackendBindings/CSharpBinding/Project/Src/Parser/Parser.cs

@@ -80,6 +80,7 @@ namespace CSharpBinding.Parser
 			CSharpParser parser = new CSharpParser();
 			parser.GenerateTypeSystemMode = !fullParseInformationRequested;
 			CompilationUnit cu = parser.Parse(fileContent.CreateReader(), fileName);
+			cu.Freeze();
 			
 			CSharpParsedFile file = cu.ToTypeSystem();
 			ParseInformation parseInfo;

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/SharpDevelopCompletionWindow.cs

@@ -88,6 +88,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 					this.CompletionList.SelectedItem = adapter;
 			}
 			this.StartOffset -= itemList.PreselectionLength;
+			this.EndOffset += itemList.PostselectionLength;
 		}
 		
 		public static readonly DependencyProperty EmptyTextProperty =

src/AddIns/DisplayBindings/XmlEditor/Project/Src/XmlCompletionItemCollection.cs

@@ -142,6 +142,7 @@ namespace ICSharpCode.XmlEditor
 		}
 		
 		public int PreselectionLength { get; set; }
+		public int PostselectionLength { get; set; }
 		
 		public void Complete(CompletionContext context, ICompletionItem item)
 		{

src/Main/Base/Project/Src/Editor/CodeCompletion/ICompletionItemList.cs

@@ -20,11 +20,15 @@ namespace ICSharpCode.SharpDevelop.Editor.CodeCompletion
 		ICompletionItem SuggestedItem { get; }
 		
 		/// <summary>
-		/// Gets the length of the preselection (text in front of the completion list that
-		/// should be included as completed expression).
+		/// Gets the length of the preselection (text in front of the caret that should be included as completed expression).
 		/// </summary>
 		int PreselectionLength { get; }
 		
+		/// <summary>
+		/// Gets the length of the postselection (text after the caret that should be included as completed expression).
+		/// </summary>
+		int PostselectionLength { get; }
+		
 		/// <summary>
 		/// Processes the specified key press.
 		/// </summary>
@@ -97,6 +101,9 @@ namespace ICSharpCode.SharpDevelop.Editor.CodeCompletion
 		/// <inheritdoc/>
 		public int PreselectionLength { get; set; }
 		
+		/// <inheritdoc/>
+		public int PostselectionLength { get; set; }
+		
 		/// <inheritdoc/>
 		public ICompletionItem SuggestedItem { get; set; }
 		

src/Main/Base/Project/Src/Services/ParserService/ParseInformation.cs

@@ -20,7 +20,6 @@ namespace ICSharpCode.SharpDevelop.Parser
 		readonly IParsedFile parsedFile;
 		IList<TagComment> tagComments = new List<TagComment>();
 		readonly bool isFullParseInformation;
-		bool isFrozen;
 		
 		public ParseInformation(IParsedFile parsedFile, bool isFullParseInformation)
 		{