AvalonEdit: Minor bugfixes / API improvements.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@3843 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Document/TextDocument.cs

@@ -216,9 +216,20 @@ namespace ICSharpCode.AvalonEdit.Document
 			}
 		}
 		
+		/// <summary>
+		/// Immediately calls <see cref="BeginUpdate()"/>,
+		/// and returns an IDisposable that calls <see cref="EndUpdate()"/>.
+		/// </summary>
+		public IDisposable RunUpdate()
+		{
+			BeginUpdate();
+			return new CallbackOnDispose(EndUpdate);
+		}
+		
 		/// <summary>
 		/// Begins a group of document changes.
-		/// DocumentParsers and some events are suspended until EndUpdate is called.
+		/// Some events are suspended until EndUpdate is called, and the <see cref="UndoStack"/> will
+		/// group all changes into a single action.
 		/// Calling BeginUpdate several times increments a counter, only after the appropriate number
 		/// of EndUpdate calls the DocumentParsers and events resume their work.
 		/// </summary>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Gui/EditingCommandHandler.cs

@@ -72,8 +72,7 @@ namespace ICSharpCode.AvalonEdit.Gui
 		{
 			TextArea textArea = GetTextArea(target);
 			if (textArea != null && textArea.Document != null) {
-				textArea.Document.BeginUpdate();
-				try {
+				using (textArea.Document.RunUpdate()) {
 					if (textArea.Selection.GetIsMultiline(textArea.Document)) {
 						DocumentLine start = textArea.Document.GetLineByOffset(textArea.Selection.SurroundingSegment.Offset);
 						DocumentLine end = textArea.Document.GetLineByOffset(textArea.Selection.SurroundingSegment.GetEndOffset());
@@ -88,8 +87,6 @@ namespace ICSharpCode.AvalonEdit.Gui
 					} else {
 						textArea.ReplaceSelectionWithText(indentationString);
 					}
-				} finally {
-					textArea.Document.EndUpdate();
 				}
 				textArea.Caret.BringCaretToView();
 				args.Handled = true;
@@ -100,8 +97,7 @@ namespace ICSharpCode.AvalonEdit.Gui
 		{
 			TextArea textArea = GetTextArea(target);
 			if (textArea != null && textArea.Document != null) {
-				textArea.Document.BeginUpdate();
-				try {
+				using (textArea.Document.RunUpdate()) {
 					DocumentLine start, end;
 					if (textArea.Selection.IsEmpty) {
 						start = end = textArea.Document.GetLineByNumber(textArea.Caret.Line);
@@ -122,8 +118,6 @@ namespace ICSharpCode.AvalonEdit.Gui
 							break;
 						start = textArea.Document.GetLineByNumber(start.LineNumber + 1);
 					}
-				} finally {
-					textArea.Document.EndUpdate();
 				}
 				textArea.Caret.BringCaretToView();
 				args.Handled = true;
@@ -159,9 +153,13 @@ namespace ICSharpCode.AvalonEdit.Gui
 			return (target, args) => {
 				TextArea textArea = GetTextArea(target);
 				if (textArea != null && textArea.Document != null) {
-					if (textArea.Selection.IsEmpty)
-						selectingCommand.Execute(args.Parameter, textArea);
-					textArea.RemoveSelectedText();
+					// call BeginUpdate before running the 'selectingCommand'
+					// so that undoing the delete does not select the deleted character
+					using (textArea.Document.RunUpdate()) {
+						if (textArea.Selection.IsEmpty)
+							selectingCommand.Execute(args.Parameter, textArea);
+						textArea.RemoveSelectedText();
+					}
 					textArea.Caret.BringCaretToView();
 					args.Handled = true;
 				}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Gui/Selection.cs

@@ -122,6 +122,25 @@ namespace ICSharpCode.AvalonEdit.Gui
 		
 		/// <inheritdoc/>
 		public abstract override int GetHashCode();
+		
+		/// <summary>
+		/// Gets whether the specified offset is included in the selection.
+		/// </summary>
+		/// <returns>True, if the selection contains the offset (selection borders inclusive);
+		/// otherwise, false.</returns>
+		public bool Contains(int offset)
+		{
+			if (this.IsEmpty)
+				return false;
+			if (this.SurroundingSegment.Contains(offset)) {
+				foreach (ISegment s in this.Segments) {
+					if (s.Contains(offset)) {
+						return true;
+					}
+				}
+			}
+			return false;
+		}
 	}
 	
 	/// <summary>
@@ -177,13 +196,10 @@ namespace ICSharpCode.AvalonEdit.Gui
 		{
 			if (!IsEmpty) {
 				var segmentsToDelete = textArea.ReadOnlySectionProvider.GetDeletableSegments(this).ToList();
-				textArea.Document.BeginUpdate();
-				try {
+				using (textArea.Document.RunUpdate()) {
 					for (int i = segmentsToDelete.Count - 1; i >= 0; i--) {
 						textArea.Document.Remove(segmentsToDelete[i].Offset, segmentsToDelete[i].Length);
 					}
-				} finally {
-					textArea.Document.EndUpdate();
 				}
 			}
 		}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Gui/SelectionMouseHandler.cs

@@ -162,7 +162,7 @@ namespace ICSharpCode.AvalonEdit.Gui
 					string text = e.Data.GetData(DataFormats.UnicodeText, true) as string;
 					if (text != null) {
 						int start = textArea.Caret.Offset;
-						if (mode == SelectionMode.Drag && Contains(textArea.Selection.SurroundingSegment, start)) {
+						if (mode == SelectionMode.Drag && textArea.Selection.Contains(start)) {
 							Debug.WriteLine("Drop: did not drop: drop target is inside selection");
 							e.Effects = DragDropEffects.None;
 						} else {
@@ -244,14 +244,21 @@ namespace ICSharpCode.AvalonEdit.Gui
 			this.currentDragDescriptor = dragDescriptor;
 			
 			DragDropEffects resultEffect;
-			try {
-				Debug.WriteLine("DoDragDrop with allowedEffects=" + allowedEffects);
-				resultEffect = DragDrop.DoDragDrop(textArea, dataObject, allowedEffects);
-				Debug.WriteLine("DoDragDrop done, resultEffect=" + resultEffect);
-			} catch (COMException ex) {
-				// ignore COM errors - don't crash on badly implemented drop targets
-				Debug.WriteLine("DoDragDrop failed: " + ex.ToString());
-				return;
+			using (textArea.AllowCaretOutsideSelection()) {
+				var oldCaretPosition = textArea.Caret.Position;
+				try {
+					Debug.WriteLine("DoDragDrop with allowedEffects=" + allowedEffects);
+					resultEffect = DragDrop.DoDragDrop(textArea, dataObject, allowedEffects);
+					Debug.WriteLine("DoDragDrop done, resultEffect=" + resultEffect);
+				} catch (COMException ex) {
+					// ignore COM errors - don't crash on badly implemented drop targets
+					Debug.WriteLine("DoDragDrop failed: " + ex.ToString());
+					return;
+				}
+				if (resultEffect == DragDropEffects.None) {
+					// reset caret if drag was aborted
+					textArea.Caret.Position = oldCaretPosition;
+				}
 			}
 			
 			this.currentDragDescriptor = null;
@@ -290,7 +297,7 @@ namespace ICSharpCode.AvalonEdit.Gui
 					if (p.X >= 0 && p.Y >= 0 && p.X <= textArea.TextView.ActualWidth && p.Y <= textArea.TextView.ActualHeight) {
 						int visualColumn;
 						int offset = GetOffsetFromMousePosition(e, out visualColumn);
-						if (SelectionContains(textArea.Selection, offset))
+						if (textArea.Selection.Contains(offset))
 							e.Cursor = Cursors.Arrow;
 						else
 							e.Cursor = Cursors.IBeam;
@@ -301,31 +308,6 @@ namespace ICSharpCode.AvalonEdit.Gui
 		}
 		#endregion
 		
-		#region ContainsOffset helper methods
-		static bool SelectionContains(Selection selection, int offset)
-		{
-			if (selection.IsEmpty)
-				return false;
-			if (offset >= 0 && Contains(selection.SurroundingSegment, offset)) {
-				foreach (ISegment s in selection.Segments) {
-					if (Contains(s, offset)) {
-						return true;
-					}
-				}
-			}
-			return false;
-		}
-		
-		static bool Contains(ISegment segment, int offset)
-		{
-			if (segment == null)
-				return false;
-			int start = segment.Offset;
-			int end = start + segment.Length;
-			return offset >= start && offset <= end;
-		}
-		#endregion
-		
 		#region LeftButtonDown
 		void textArea_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
 		{
@@ -335,7 +317,7 @@ namespace ICSharpCode.AvalonEdit.Gui
 				if (AllowTextDragDrop && e.ClickCount == 1 && !shift) {
 					int visualColumn;
 					int offset = GetOffsetFromMousePosition(e, out visualColumn);
-					if (SelectionContains(textArea.Selection, offset)) {
+					if (textArea.Selection.Contains(offset)) {
 						if (textArea.CaptureMouse()) {
 							mode = SelectionMode.PossibleDragStart;
 							possibleDragStartMousePos = e.GetPosition(textArea);

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Gui/TextArea.cs

@@ -76,6 +76,7 @@ namespace ICSharpCode.AvalonEdit
 			textView.InsertLayer(new SelectionLayer(this), KnownLayer.Selection, LayerInsertionPosition.Replace);
 			
 			caret = new Caret(this);
+			caret.PositionChanged += (sender, e) => RequestSelectionValidation();
 			this.CommandBindings.Add(new CommandBinding(ApplicationCommands.Undo, ExecuteUndo, CanExecuteUndo));
 			this.CommandBindings.Add(new CommandBinding(ApplicationCommands.Redo, ExecuteRedo, CanExecuteRedo));
 			
@@ -234,6 +235,63 @@ namespace ICSharpCode.AvalonEdit
 		}
 		#endregion
 		
+		#region Force caret to stay inside selection
+		bool ensureSelectionValidRequested;
+		int allowCaretOutsideSelection;
+		
+		void RequestSelectionValidation()
+		{
+			if (!ensureSelectionValidRequested && allowCaretOutsideSelection == 0) {
+				ensureSelectionValidRequested = true;
+				Dispatcher.BeginInvoke(DispatcherPriority.Normal, new Action(EnsureSelectionValid));
+			}
+		}
+		
+		/// <summary>
+		/// Code that updates only the caret but not the selection can cause confusion when
+		/// keys like 'Delete' delete the (possibly invisible) selected text and not the
+		/// text around the caret (where the will jump to).
+		/// 
+		/// So we'll ensure that the caret is inside the selection.
+		/// (when the caret is not in the selection, we'll clear the selection)
+		/// 
+		/// This method is invoked using the Dispatcher so that code may temporarily violate this rule
+		/// (e.g. most 'exten selection' methods work by first setting the caret, then the selection),
+		/// it's sufficient to fix it after any event handlers have run.
+		/// </summary>
+		void EnsureSelectionValid()
+		{
+			ensureSelectionValidRequested = false;
+			if (allowCaretOutsideSelection == 0) {
+				if (!selection.Contains(caret.Offset))
+					this.Selection = Selection.Empty;
+			}
+		}
+		
+		/// <summary>
+		/// Temporarily allows positioning the caret outside the selection.
+		/// Dispose the returned IDisposable to revert the allowance.
+		/// </summary>
+		/// <remarks>
+		/// The text area only forces the caret to be inside the selection when other events
+		/// have finished running (using the dispatcher), so you don't have to use this method
+		/// for temporarily positioning the caret in event handlers.
+		/// This method is only necessary if you want to run the WPF dispatcher, e.g. if you
+		/// perform a drag'n'drop operation.
+		/// </remarks>
+		public IDisposable AllowCaretOutsideSelection()
+		{
+			VerifyAccess();
+			allowCaretOutsideSelection++;
+			return new CallbackOnDispose(
+				delegate {
+					VerifyAccess();
+					allowCaretOutsideSelection--;
+					RequestSelectionValidation();
+				});
+		}
+		#endregion
+		
 		#region Properties
 		readonly Caret caret;
 		
@@ -483,6 +541,12 @@ namespace ICSharpCode.AvalonEdit
 		{
 			base.OnTextInput(e);
 			if (!e.Handled) {
+				if (e.Text == "\x1b") {
+					// ASCII 0x1b = ESC.
+					// WPF produces a TextInput event with that old ASCII control char
+					// when Escape is pressed. We'll just ignore it.
+					return;
+				}
 				TextDocument document = this.Document;
 				if (document != null) {
 					ReplaceSelectionWithText(e.Text);
@@ -506,14 +570,11 @@ namespace ICSharpCode.AvalonEdit
 		
 		internal void ReplaceSelectionWithText(string newText)
 		{
-			Document.BeginUpdate();
-			try {
+			using (Document.RunUpdate()) {
 				RemoveSelectedText();
 				if (ReadOnlySectionProvider.CanInsert(Caret.Offset)) {
 					Document.Insert(Caret.Offset, newText);
 				}
-			} finally {
-				Document.EndUpdate();
 			}
 		}
 		#endregion

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Gui/TextEditor.cs

@@ -246,23 +246,7 @@ namespace ICSharpCode.AvalonEdit
 		/// </summary>
 		public IDisposable DeclareChangeBlock()
 		{
-			return new ChangeBlock(GetOrCreateDocument());
-		}
-		
-		sealed class ChangeBlock : IDisposable
-		{
-			TextDocument document;
-			
-			public ChangeBlock(TextDocument document)
-			{
-				this.document = document;
-				document.BeginUpdate();
-			}
-			
-			public void Dispose()
-			{
-				document.EndUpdate();
-			}
+			return GetOrCreateDocument().RunUpdate();
 		}
 		
 		/// <summary>
@@ -510,13 +494,10 @@ namespace ICSharpCode.AvalonEdit
 					throw new ArgumentNullException("value");
 				TextArea textArea = this.TextArea;
 				if (textArea != null && textArea.Document != null) {
-					textArea.Document.BeginUpdate();
-					try {
+					using (textArea.Document.RunUpdate()) {
 						textArea.RemoveSelectedText();
 						if (textArea.ReadOnlySectionProvider.CanInsert(textArea.Caret.Offset))
 							textArea.Document.Insert(textArea.Caret.Offset, value);
-					} finally {
-						textArea.Document.EndUpdate();
 					}
 				}
 			}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Gui/TextView.cs

@@ -39,7 +39,7 @@ namespace ICSharpCode.AvalonEdit.Gui
 		#region Constructor
 		static TextView()
 		{
-			ClipToBoundsProperty.OverrideMetadata(typeof(TextView), new FrameworkPropertyMetadata(true));
+			ClipToBoundsProperty.OverrideMetadata(typeof(TextView), new FrameworkPropertyMetadata(Boxes.True));
 		}
 		
 		/// <summary>

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

@@ -254,6 +254,7 @@
     <Compile Include="Utils\CompressingTreeList.cs" />
     <Compile Include="Utils\Constants.cs" />
     <Compile Include="Utils\DelayedEvents.cs" />
+    <Compile Include="Utils\CallbackOnDispose.cs" />
     <Compile Include="Utils\Empty.cs" />
     <Compile Include="Utils\ExtensionMethods.cs" />
     <Compile Include="Utils\FileReader.cs" />

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/CallbackOnDispose.cs

@@ -0,0 +1,39 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <author name="Daniel Grunwald"/>
+//     <version>$Revision$</version>
+// </file>
+
+using System;
+using System.Diagnostics;
+using System.Threading;
+
+namespace ICSharpCode.AvalonEdit.Utils
+{
+	/// <summary>
+	/// Invokes an action when it is disposed.
+	/// </summary>
+	/// <remarks>
+	/// This class ensures the callback is invoked at most once,
+	/// even when Dispose is called on multiple theadeds.
+	/// </remarks>
+	sealed class CallbackOnDispose : IDisposable
+	{
+		Action action;
+		
+		public CallbackOnDispose(Action action)
+		{
+			Debug.Assert(action != null);
+			this.action = action;
+		}
+		
+		public void Dispose()
+		{
+			Action a = Interlocked.Exchange(ref action, null);
+			if (a != null) {
+				a();
+			}
+		}
+	}
+}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/ExtensionMethods.cs

@@ -109,5 +109,20 @@ namespace ICSharpCode.AvalonEdit.Utils
 		{
 			return segment.Offset + segment.Length;
 		}
+		
+		/// <summary>
+		/// Gets whether the segment contains the offset.
+		/// </summary>
+		/// <returns>
+		/// True, if offset is between segment.Start and segment.End (inclusive); otherwise, false.
+		/// </returns>
+		public static bool Contains(this ISegment segment, int offset)
+		{
+			if (segment == null)
+				return false;
+			int start = segment.Offset;
+			int end = start + segment.Length;
+			return offset >= start && offset <= end;
+		}
 	}
 }