Implemented SD-1853 - AvalonEdit: Distinguish between 'end of line' and 'start of next line' at word wrap positions

Also, the Home/End keys now apply to the current TextLine, not the whole VisualLine.

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs

@@ -348,7 +348,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 				RevalidateVisualColumn(visualLine);
 			}
 			
-			TextLine textLine = visualLine.GetTextLine(position.VisualColumn);
+			TextLine textLine = visualLine.GetTextLine(position.VisualColumn, position.IsAtEndOfLine);
 			double xPos = visualLine.GetTextLineVisualXPosition(textLine, position.VisualColumn);
 			double lineTop = visualLine.GetTextLineVisualYPosition(textLine, VisualYPosition.TextTop);
 			double lineBottom = visualLine.GetTextLineVisualYPosition(textLine, VisualYPosition.TextBottom);

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/CaretNavigationCommandHandler.cs

@@ -177,7 +177,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			DocumentLine caretLine = textArea.Document.GetLineByNumber(textArea.Caret.Line);
 			VisualLine visualLine = textArea.TextView.GetOrConstructVisualLine(caretLine);
 			TextViewPosition caretPosition = textArea.Caret.Position;
-			TextLine textLine = visualLine.GetTextLine(caretPosition.VisualColumn);
+			TextLine textLine = visualLine.GetTextLine(caretPosition.VisualColumn, caretPosition.IsAtEndOfLine);
 			switch (direction) {
 				case CaretMovementType.CharLeft:
 					MoveCaretLeft(textArea, caretPosition, visualLine, CaretPositioningMode.Normal);
@@ -204,10 +204,10 @@ namespace ICSharpCode.AvalonEdit.Editing
 					SetCaretPosition(textArea, -1, textArea.Document.TextLength);
 					break;
 				case CaretMovementType.LineStart:
-					MoveCaretToStartOfLine(textArea, visualLine);
+					MoveCaretToStartOfLine(textArea, visualLine, textLine);
 					break;
 				case CaretMovementType.LineEnd:
-					MoveCaretToEndOfLine(textArea, visualLine);
+					MoveCaretToEndOfLine(textArea, visualLine, textLine);
 					break;
 				default:
 					throw new NotSupportedException(direction.ToString());
@@ -216,9 +216,11 @@ namespace ICSharpCode.AvalonEdit.Editing
 		#endregion
 		
 		#region Home/End
-		static void MoveCaretToStartOfLine(TextArea textArea, VisualLine visualLine)
+		static void MoveCaretToStartOfLine(TextArea textArea, VisualLine visualLine, TextLine textLine)
 		{
-			int newVC = visualLine.GetNextCaretPosition(-1, LogicalDirection.Forward, CaretPositioningMode.WordStart, textArea.Selection.EnableVirtualSpace);
+			int newVC = visualLine.GetTextLineVisualStartColumn(textLine);
+			if (newVC == 0)
+				newVC = visualLine.GetNextCaretPosition(newVC - 1, LogicalDirection.Forward, CaretPositioningMode.WordStart, textArea.Selection.EnableVirtualSpace);
 			if (newVC < 0)
 				throw ThrowUtil.NoValidCaretPosition();
 			// when the caret is already at the start of the text, jump to start before whitespace
@@ -228,11 +230,11 @@ namespace ICSharpCode.AvalonEdit.Editing
 			SetCaretPosition(textArea, newVC, offset);
 		}
 		
-		static void MoveCaretToEndOfLine(TextArea textArea, VisualLine visualLine)
+		static void MoveCaretToEndOfLine(TextArea textArea, VisualLine visualLine, TextLine textLine)
 		{
-			int newVC = visualLine.VisualLength;
+			int newVC = visualLine.GetTextLineVisualStartColumn(textLine) + textLine.Length - textLine.TrailingWhitespaceLength;
 			int offset = visualLine.FirstDocumentLine.Offset + visualLine.GetRelativeOffset(newVC);
-			SetCaretPosition(textArea, newVC, offset);
+			SetCaretPosition(textArea, newVC, offset, isAtEndOfLine: true);
 		}
 		#endregion
 		
@@ -365,9 +367,9 @@ namespace ICSharpCode.AvalonEdit.Editing
 			SetCaretPosition(textArea, newVisualColumn, newOffset);
 		}
 		
-		static void SetCaretPosition(TextArea textArea, int newVisualColumn, int newOffset)
+		static void SetCaretPosition(TextArea textArea, int newVisualColumn, int newOffset, bool isAtEndOfLine = false)
 		{
-			textArea.Caret.Position = new TextViewPosition(textArea.Document.GetLocation(newOffset), newVisualColumn);
+			textArea.Caret.Position = new TextViewPosition(textArea.Document.GetLocation(newOffset), newVisualColumn) { IsAtEndOfLine = isAtEndOfLine };
 			textArea.Caret.DesiredXPos = double.NaN;
 		}
 		#endregion

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/ImeNativeWrapper.cs

@@ -169,7 +169,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			// in those cases. It should be refreshed immediately.
 			if (source.RootVisual == null || !source.RootVisual.IsAncestorOf(textView))
 				return EMPTY_RECT;
-			TextLine line = vl.GetTextLine(pos.VisualColumn);
+			TextLine line = vl.GetTextLine(pos.VisualColumn, pos.IsAtEndOfLine);
 			Rect displayRect;
 			// calculate the display rect for the current character
 			if (pos.VisualColumn < vl.VisualLengthWithEndOfLineMarker) {

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/RectangleSelection.cs

@@ -148,7 +148,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			DocumentLine documentLine = textArea.Document.GetLineByNumber(pos.Line);
 			VisualLine visualLine = textArea.TextView.GetOrConstructVisualLine(documentLine);
 			int vc = visualLine.ValidateVisualColumn(pos, true);
-			TextLine textLine = visualLine.GetTextLine(vc);
+			TextLine textLine = visualLine.GetTextLine(vc, pos.IsAtEndOfLine);
 			return visualLine.GetTextLineVisualXPosition(textLine, vc);
 		}
 		

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

@@ -166,9 +166,10 @@ namespace ICSharpCode.AvalonEdit.Editing
 			if (e.Data.GetDataPresent(DataFormats.UnicodeText, true)) {
 				e.Handled = true;
 				int visualColumn;
-				int offset = GetOffsetFromMousePosition(e.GetPosition(textArea.TextView), out visualColumn);
+				bool isAtEndOfLine;
+				int offset = GetOffsetFromMousePosition(e.GetPosition(textArea.TextView), out visualColumn, out isAtEndOfLine);
 				if (offset >= 0) {
-					textArea.Caret.Position = new TextViewPosition(textArea.Document.GetLocation(offset), visualColumn);
+					textArea.Caret.Position = new TextViewPosition(textArea.Document.GetLocation(offset), visualColumn) { IsAtEndOfLine = isAtEndOfLine };
 					textArea.Caret.DesiredXPos = double.NaN;
 					if (textArea.ReadOnlySectionProvider.CanInsert(offset)) {
 						if ((e.AllowedEffects & DragDropEffects.Move) == DragDropEffects.Move
@@ -359,7 +360,8 @@ namespace ICSharpCode.AvalonEdit.Editing
 					Point p = e.GetPosition(textArea.TextView);
 					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);
+						bool isAtEndOfLine;
+						int offset = GetOffsetFromMousePosition(e, out visualColumn, out isAtEndOfLine);
 						if (textArea.Selection.Contains(offset))
 							e.Cursor = Cursors.Arrow;
 						else
@@ -380,7 +382,8 @@ namespace ICSharpCode.AvalonEdit.Editing
 				bool shift = (modifiers & ModifierKeys.Shift) == ModifierKeys.Shift;
 				if (enableTextDragDrop && e.ClickCount == 1 && !shift) {
 					int visualColumn;
-					int offset = GetOffsetFromMousePosition(e, out visualColumn);
+					bool isAtEndOfLine;
+					int offset = GetOffsetFromMousePosition(e, out visualColumn, out isAtEndOfLine);
 					if (textArea.Selection.Contains(offset)) {
 						if (textArea.CaptureMouse()) {
 							mode = SelectionMode.PossibleDragStart;
@@ -488,12 +491,12 @@ namespace ICSharpCode.AvalonEdit.Editing
 			}
 		}
 		
-		int GetOffsetFromMousePosition(MouseEventArgs e, out int visualColumn)
+		int GetOffsetFromMousePosition(MouseEventArgs e, out int visualColumn, out bool isAtEndOfLine)
 		{
-			return GetOffsetFromMousePosition(e.GetPosition(textArea.TextView), out visualColumn);
+			return GetOffsetFromMousePosition(e.GetPosition(textArea.TextView), out visualColumn, out isAtEndOfLine);
 		}
 		
-		int GetOffsetFromMousePosition(Point positionRelativeToTextView, out int visualColumn)
+		int GetOffsetFromMousePosition(Point positionRelativeToTextView, out int visualColumn, out bool isAtEndOfLine)
 		{
 			visualColumn = 0;
 			TextView textView = textArea.TextView;
@@ -507,9 +510,10 @@ namespace ICSharpCode.AvalonEdit.Editing
 				pos.Y = textView.DocumentHeight - ExtensionMethods.Epsilon;
 			VisualLine line = textView.GetVisualLineFromVisualTop(pos.Y);
 			if (line != null) {
-				visualColumn = line.GetVisualColumn(pos, textArea.Selection.EnableVirtualSpace);
+				visualColumn = line.GetVisualColumn(pos, textArea.Selection.EnableVirtualSpace, out isAtEndOfLine);
 				return line.GetRelativeOffset(visualColumn) + line.FirstDocumentLine.Offset;
 			}
+			isAtEndOfLine = false;
 			return -1;
 		}
 		
@@ -568,16 +572,19 @@ namespace ICSharpCode.AvalonEdit.Editing
 		void SetCaretOffsetToMousePosition(MouseEventArgs e, ISegment allowedSegment)
 		{
 			int visualColumn;
+			bool isAtEndOfLine;
 			int offset;
-			if (mode == SelectionMode.Rectangular)
+			if (mode == SelectionMode.Rectangular) {
 				offset = GetOffsetFromMousePositionFirstTextLineOnly(e.GetPosition(textArea.TextView), out visualColumn);
-			else
-				offset = GetOffsetFromMousePosition(e, out visualColumn);
+				isAtEndOfLine = true;
+			} else {
+				offset = GetOffsetFromMousePosition(e, out visualColumn, out isAtEndOfLine);
+			}
 			if (allowedSegment != null) {
 				offset = offset.CoerceValue(allowedSegment.Offset, allowedSegment.EndOffset);
 			}
 			if (offset >= 0) {
-				textArea.Caret.Position = new TextViewPosition(textArea.Document.GetLocation(offset), visualColumn);
+				textArea.Caret.Position = new TextViewPosition(textArea.Document.GetLocation(offset), visualColumn) { IsAtEndOfLine = isAtEndOfLine };
 				textArea.Caret.DesiredXPos = double.NaN;
 			}
 		}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/SimpleSelection.cs

@@ -84,11 +84,13 @@ namespace ICSharpCode.AvalonEdit.Editing
 		{
 			if (e == null)
 				throw new ArgumentNullException("e");
-			return Selection.Create(
-				textArea,
-				new TextViewPosition(textArea.Document.GetLocation(e.GetNewOffset(startOffset, AnchorMovementType.Default)), start.VisualColumn),
-				new TextViewPosition(textArea.Document.GetLocation(e.GetNewOffset(endOffset, AnchorMovementType.Default)), end.VisualColumn)
-			);
+			TextViewPosition newStart = start;
+			TextViewPosition newEnd = end;
+			// by changing the existing TextViewPosition, we preserve the VisualColumn (though it might become invalid)
+			// and the IsAtEndOfLine property.
+			newStart.Location = textArea.Document.GetLocation(e.GetNewOffset(startOffset, AnchorMovementType.Default));
+			newEnd.Location   = textArea.Document.GetLocation(e.GetNewOffset(endOffset, AnchorMovementType.Default));
+			return Selection.Create(textArea, newStart, newEnd);
 		}
 		
 		/// <inheritdoc/>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/BackgroundGeometryBuilder.cs

@@ -125,8 +125,8 @@ namespace ICSharpCode.AvalonEdit.Rendering
 				start = new TextViewPosition(textView.Document.GetLocation(sel.StartOffset), sel.StartVisualColumn);
 				end = new TextViewPosition(textView.Document.GetLocation(sel.EndOffset), sel.EndVisualColumn);
 			} else {
-				start = new TextViewPosition(textView.Document.GetLocation(segmentStart), -1);
-				end = new TextViewPosition(textView.Document.GetLocation(segmentEnd), -1);
+				start = new TextViewPosition(textView.Document.GetLocation(segmentStart));
+				end = new TextViewPosition(textView.Document.GetLocation(segmentEnd));
 			}
 			
 			foreach (VisualLine vl in textView.VisualLines) {

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

@@ -1757,9 +1757,7 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			VisualLine line = GetVisualLineFromVisualTop(visualPosition.Y);
 			if (line == null)
 				return null;
-			int visualColumn = line.GetVisualColumn(visualPosition);
-			int documentOffset = line.GetRelativeOffset(visualColumn) + line.FirstDocumentLine.Offset;
-			return new TextViewPosition(document.GetLocation(documentOffset), visualColumn);
+			return line.GetTextViewPosition(visualPosition, Options.EnableVirtualSpace);
 		}
 		
 		/// <summary>
@@ -1777,9 +1775,7 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			VisualLine line = GetVisualLineFromVisualTop(visualPosition.Y);
 			if (line == null)
 				return null;
-			int visualColumn = line.GetVisualColumnFloor(visualPosition);
-			int documentOffset = line.GetRelativeOffset(visualColumn) + line.FirstDocumentLine.Offset;
-			return new TextViewPosition(document.GetLocation(documentOffset), visualColumn);
+			return line.GetTextViewPositionFloor(visualPosition, Options.EnableVirtualSpace);
 		}
 		#endregion
 		

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs

@@ -307,13 +307,21 @@ namespace ICSharpCode.AvalonEdit.Rendering
 		/// Gets the text line containing the specified visual column.
 		/// </summary>
 		public TextLine GetTextLine(int visualColumn)
+		{
+			return GetTextLine(visualColumn, false);
+		}
+		
+		/// <summary>
+		/// Gets the text line containing the specified visual column.
+		/// </summary>
+		public TextLine GetTextLine(int visualColumn, bool isAtEndOfLine)
 		{
 			if (visualColumn < 0)
 				throw new ArgumentOutOfRangeException("visualColumn");
 			if (visualColumn >= VisualLengthWithEndOfLineMarker)
 				return TextLines[TextLines.Count - 1];
 			foreach (TextLine line in TextLines) {
-				if (visualColumn < line.Length)
+				if (isAtEndOfLine ? visualColumn <= line.Length : visualColumn < line.Length)
 					return line;
 				else
 					visualColumn -= line.Length;
@@ -437,6 +445,14 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			return GetVisualColumn(GetTextLineByVisualYPosition(point.Y), point.X, allowVirtualSpace);
 		}
 		
+		internal int GetVisualColumn(Point point, bool allowVirtualSpace, out bool isAtEndOfLine)
+		{
+			var textLine = GetTextLineByVisualYPosition(point.Y);
+			int vc = GetVisualColumn(textLine, point.X, allowVirtualSpace);
+			isAtEndOfLine = (vc >= GetTextLineVisualStartColumn(textLine) + textLine.Length);
+			return vc;
+		}
+		
 		/// <summary>
 		/// Gets the visual column from a document position (relative to top left of the document).
 		/// If the user clicks between two visual columns, rounds to the nearest column.
@@ -497,9 +513,16 @@ namespace ICSharpCode.AvalonEdit.Rendering
 		/// If the user clicks between two visual columns, returns the first of those columns.
 		/// </summary>
 		public int GetVisualColumnFloor(Point point, bool allowVirtualSpace)
+		{
+			bool tmp;
+			return GetVisualColumnFloor(point, allowVirtualSpace, out tmp);
+		}
+		
+		internal int GetVisualColumnFloor(Point point, bool allowVirtualSpace, out bool isAtEndOfLine)
 		{
 			TextLine textLine = GetTextLineByVisualYPosition(point.Y);
 			if (point.X > textLine.WidthIncludingTrailingWhitespace) {
+				isAtEndOfLine = true;
 				if (allowVirtualSpace && textLine == TextLines[TextLines.Count - 1]) {
 					// clicking virtual space in the last line
 					int virtualX = (int)((point.X - textLine.WidthIncludingTrailingWhitespace) / textView.WideSpaceWidth);
@@ -510,11 +533,47 @@ namespace ICSharpCode.AvalonEdit.Rendering
 					// specially and return the line's end column instead.
 					return GetTextLineVisualStartColumn(textLine) + textLine.Length;
 				}
+			} else {
+				isAtEndOfLine = false;
 			}
 			CharacterHit ch = textLine.GetCharacterHitFromDistance(point.X);
 			return ch.FirstCharacterIndex;
 		}
 		
+		/// <summary>
+		/// Gets the text view position from the specified visual position.
+		/// If the position is within a character, it is rounded to the next character boundary.
+		/// </summary>
+		/// <param name="visualPosition">The position in WPF device-independent pixels relative
+		/// to the top left corner of the document.</param>
+		/// <param name="allowVirtualSpace">Controls whether positions in virtual space may be returned.</param>
+		public TextViewPosition GetTextViewPosition(Point visualPosition, bool allowVirtualSpace)
+		{
+			bool isAtEndOfLine;
+			int visualColumn = GetVisualColumn(visualPosition, allowVirtualSpace, out isAtEndOfLine);
+			int documentOffset = GetRelativeOffset(visualColumn) + this.FirstDocumentLine.Offset;
+			TextViewPosition pos = new TextViewPosition(this.Document.GetLocation(documentOffset), visualColumn);
+			pos.IsAtEndOfLine = isAtEndOfLine;
+			return pos;
+		}
+		
+		/// <summary>
+		/// Gets the text view position from the specified visual position.
+		/// If the position is inside a character, the position in front of the character is returned.
+		/// </summary>
+		/// <param name="visualPosition">The position in WPF device-independent pixels relative
+		/// to the top left corner of the document.</param>
+		/// <param name="allowVirtualSpace">Controls whether positions in virtual space may be returned.</param>
+		public TextViewPosition GetTextViewPositionFloor(Point visualPosition, bool allowVirtualSpace)
+		{
+			bool isAtEndOfLine;
+			int visualColumn = GetVisualColumnFloor(visualPosition, allowVirtualSpace, out isAtEndOfLine);
+			int documentOffset = GetRelativeOffset(visualColumn) + this.FirstDocumentLine.Offset;
+			TextViewPosition pos = new TextViewPosition(this.Document.GetLocation(documentOffset), visualColumn);
+			pos.IsAtEndOfLine = isAtEndOfLine;
+			return pos;
+		}
+		
 		/// <summary>
 		/// Gets whether the visual line was disposed.
 		/// </summary>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/TextViewPosition.cs

@@ -13,6 +13,7 @@ namespace ICSharpCode.AvalonEdit
 	public struct TextViewPosition : IEquatable<TextViewPosition>
 	{
 		int line, column, visualColumn;
+		bool isAtEndOfLine;
 		
 		/// <summary>
 		/// Gets/Sets Location.
@@ -52,6 +53,21 @@ namespace ICSharpCode.AvalonEdit
 			set { visualColumn = value; }
 		}
 		
+		/// <summary>
+		/// When word-wrap is enabled and a line is wrapped at a position where there is no space character;
+		/// then both the end of the first TextLine and the beginning of the second TextLine
+		/// refer to the same position in the document, and also have the same visual column.
+		/// In this case, the IsAtEndOfLine property is used to distinguish between the two cases:
+		/// the value <c>true</c> indicates that the position refers to the end of the previous TextLine;
+		/// the value <c>false</c> indicates that the position refers to the beginning of the next TextLine.
+		/// 
+		/// If this position is not at such a wrapping position, the value of this property has no effect.
+		/// </summary>
+		public bool IsAtEndOfLine {
+			get { return isAtEndOfLine; }
+			set { isAtEndOfLine = value; }
+		}
+		
 		/// <summary>
 		/// Creates a new TextViewPosition instance.
 		/// </summary>
@@ -60,6 +76,7 @@ namespace ICSharpCode.AvalonEdit
 			this.line = line;
 			this.column = column;
 			this.visualColumn = visualColumn;
+			this.isAtEndOfLine = false;
 		}
 		
 		/// <summary>
@@ -78,6 +95,7 @@ namespace ICSharpCode.AvalonEdit
 			this.line = location.Line;
 			this.column = location.Column;
 			this.visualColumn = visualColumn;
+			this.isAtEndOfLine = false;
 		}
 		
 		/// <summary>
@@ -92,8 +110,8 @@ namespace ICSharpCode.AvalonEdit
 		public override string ToString()
 		{
 			return string.Format(CultureInfo.InvariantCulture,
-			                     "[TextViewPosition Line={0} Column={1} VisualColumn={2}]",
-			                     this.line, this.column, this.visualColumn);
+			                     "[TextViewPosition Line={0} Column={1} VisualColumn={2} IsAtEndOfLine={3}]",
+			                     this.line, this.column, this.visualColumn, this.isAtEndOfLine);
 		}
 		
 		/// <summary>