Fixed SD2-458: Tab is always replaced with 4 spaces

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@551 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/ICSharpCode.TextEditor/Project/Src/Actions/MiscActions.cs

@@ -17,11 +17,22 @@ namespace ICSharpCode.TextEditor.Actions
 	public class Tab : AbstractEditAction
 	{
 		public static string GetIndentationString(IDocument document)
+		{
+			return GetIndentationString(document, null);
+		}
+		
+		public static string GetIndentationString(IDocument document, TextArea textArea)
 		{
 			StringBuilder indent = new StringBuilder();
 			
 			if (document.TextEditorProperties.ConvertTabsToSpaces) {
-				indent.Append(new String(' ', document.TextEditorProperties.TabIndent));
+				int tabIndent = document.TextEditorProperties.TabIndent;
+				if (textArea != null) {
+					int column = textArea.TextView.GetVisualColumn(textArea.Caret.Line, textArea.Caret.Column);
+					indent.Append(new String(' ', tabIndent - column % tabIndent));
+				} else {
+					indent.Append(new String(' ', tabIndent));
+				}
 			} else {
 				indent.Append('\t');
 			}
@@ -57,10 +68,10 @@ namespace ICSharpCode.TextEditor.Actions
 		{
 			switch (textArea.Caret.CaretMode) {
 				case CaretMode.InsertMode:
-					textArea.InsertString(GetIndentationString(textArea.Document));
+					textArea.InsertString(GetIndentationString(textArea.Document, textArea));
 					break;
 				case CaretMode.OverwriteMode:
-					string indentStr = GetIndentationString(textArea.Document);
+					string indentStr = GetIndentationString(textArea.Document, textArea);
 					textArea.ReplaceChar(indentStr[0]);
 					if (indentStr.Length > 1) {
 						textArea.InsertString(indentStr.Substring(1));

src/Libraries/ICSharpCode.TextEditor/Project/Src/Gui/TextView.cs

@@ -900,7 +900,9 @@ namespace ICSharpCode.TextEditor
 			for (int j = currentLine.Length; j < end; j++) {
 				drawingPos += WideSpaceWidth;
 			}
-			column += (int)(drawingPos / WideSpaceWidth);
+			// add one pixel in column calculation to account for floating point calculation errors
+			column += (int)((drawingPos + 1) / WideSpaceWidth);
+			
 			/* OLD Code (does not work for fonts like Verdana)
 			for (int j = start; j < end; ++j) {
 				char ch;