Merge branch 'v2_combining-tab-fix_3011' into v2_tabview-frame-fix_2882

Terminal.Gui/Text/TextFormatter.cs

@@ -169,6 +169,15 @@ namespace Terminal.Gui {
 			return StringExtensions.ToString (runes);
 		}
 
+		static string ReplaceTABWithSpaces (string str, int tabWidth)
+		{
+			if (tabWidth == 0) {
+				return str.Replace ("\t", "");
+			}
+
+			return str.Replace ("\t", new string (' ', tabWidth));
+		}
+
 		/// <summary>
 		/// Splits all newlines in the <paramref name="text"/> into a list
 		/// and supports both CRLF and LF, preserving the ending newline.
@@ -368,7 +377,17 @@ namespace Terminal.Gui {
 						if (end == start) {
 							end = start + width;
 						}
-						lines.Add (StringExtensions.ToString (runes.GetRange (start, end - start)));
+						var zeroLength = 0;
+						for (int i = end; i < runes.Count - start; i++) {
+							var r = runes [i];
+							if (r.GetColumns () == 0) {
+								zeroLength++;
+							} else {
+								break;
+							}
+						}
+						lines.Add (StringExtensions.ToString (runes.GetRange (start, end - start + zeroLength)));
+						end += zeroLength;
 						start = end;
 						if (runes [end].Value == ' ') {
 							start++;
@@ -472,12 +491,13 @@ namespace Terminal.Gui {
 				if (IsHorizontalDirection (textDirection)) {
 					return StringExtensions.ToString (runes.GetRange (0, GetLengthThatFits (text, width)));
 				} else {
-					return StringExtensions.ToString (runes.GetRange (0, width));
+					var zeroLength = runes.Sum (r => r.GetColumns () == 0 ? 1 : 0);
+					return StringExtensions.ToString (runes.GetRange (0, width + zeroLength));
 				}
 			} else {
 				if (justify) {
 					return Justify (text, width, ' ', textDirection);
-				} else if (IsHorizontalDirection (textDirection) && text.GetColumns () > width) {
+				} else if (IsHorizontalDirection (textDirection) && GetRuneWidth (text.GetColumns ()) > width) {
 					return StringExtensions.ToString (runes.GetRange (0, GetLengthThatFits (text, width)));
 				}
 				return text;
@@ -602,6 +622,7 @@ namespace Terminal.Gui {
 
 			if (wordWrap == false) {
 				text = ReplaceCRLFWithSpace (text);
+				text = ReplaceTABWithSpaces (text, tabWidth);
 				lineResult.Add (ClipAndJustify (text, width, justify, textDirection));
 				return lineResult;
 			}
@@ -623,7 +644,7 @@ namespace Terminal.Gui {
 				}
 			}
 			foreach (var line in WordWrapText (StringExtensions.ToString (runes.GetRange (lp, runeCount - lp)), width, preserveTrailingSpaces, tabWidth, textDirection)) {
-				lineResult.Add (ClipAndJustify (line, width, justify, textDirection));
+				lineResult.Add (ClipAndJustify (ReplaceTABWithSpaces (line, tabWidth), width, justify, textDirection));
 			}
 
 			return lineResult;
@@ -654,7 +675,7 @@ namespace Terminal.Gui {
 			var max = 0;
 			result.ForEach (s => {
 				var m = 0;
-				s.ToRuneList ().ForEach (r => m += Math.Max (r.GetColumns (), 1));
+				s.ToRuneList ().ForEach (r => m += GetRuneWidth (r.GetColumns ()));
 				if (m > max) {
 					max = m;
 				}
@@ -688,7 +709,7 @@ namespace Terminal.Gui {
 			for (int i = (startIndex == -1 ? 0 : startIndex); i < (length == -1 ? lines.Count : startIndex + length); i++) {
 				var runes = lines [i];
 				if (runes.Length > 0)
-					max += runes.EnumerateRunes ().Max (r => Math.Max (r.GetColumns (), 1));
+					max += runes.EnumerateRunes ().Max (r => GetRuneWidth (r.GetColumns ()));
 			}
 			return max;
 		}
@@ -706,7 +727,7 @@ namespace Terminal.Gui {
 			var max = 0;
 			var runes = text.ToRunes ();
 			for (int i = (startIndex == -1 ? 0 : startIndex); i < (length == -1 ? runes.Length : startIndex + length); i++) {
-				max += Math.Max (runes [i].GetColumns (), 1);
+				max += GetRuneWidth (runes [i].GetColumns ());
 			}
 			return max;
 		}
@@ -734,7 +755,7 @@ namespace Terminal.Gui {
 			var runesLength = 0;
 			var runeIdx = 0;
 			for (; runeIdx < runes.Count; runeIdx++) {
-				var runeWidth = Math.Max (runes [runeIdx].GetColumns (), 1);
+				var runeWidth = GetRuneWidth (runes [runeIdx].GetColumns ());
 				if (runesLength + runeWidth > columns) {
 					break;
 				}
@@ -743,6 +764,15 @@ namespace Terminal.Gui {
 			return runeIdx;
 		}
 
+		private static int GetRuneWidth (int runeWidth)
+		{
+			if (runeWidth < 0 || runeWidth > 0) {
+				return Math.Max (runeWidth, 1);
+			}
+
+			return runeWidth;
+		}
+
 		/// <summary>
 		/// Gets the index position from the list based on the <paramref name="width"/>.
 		/// </summary>
@@ -756,7 +786,7 @@ namespace Terminal.Gui {
 			for (; lineIdx < lines.Count; lineIdx++) {
 				var runes = lines [lineIdx].ToRuneList ();
 				var maxRruneWidth = runes.Count > 0
-					? runes.Max (r => Math.Max (r.GetColumns (), 1)) : 1;
+					? runes.Max (r => GetRuneWidth (r.GetColumns ())) : 1;
 				if (runesLength + maxRruneWidth > width) {
 					break;
 				}
@@ -772,8 +802,9 @@ namespace Terminal.Gui {
 		/// <param name="y">The y location of the rectangle</param>
 		/// <param name="text">The text to measure</param>
 		/// <param name="direction">The text direction.</param>
+		/// <param name="tabWidth">The number of columns used for a tab.</param>
 		/// <returns></returns>
-		public static Rect CalcRect (int x, int y, string text, TextDirection direction = TextDirection.LeftRight_TopBottom)
+		public static Rect CalcRect (int x, int y, string text, TextDirection direction = TextDirection.LeftRight_TopBottom, int tabWidth = 0)
 		{
 			if (string.IsNullOrEmpty (text)) {
 				return new Rect (new Point (x, y), Size.Empty);
@@ -795,9 +826,16 @@ namespace Terminal.Gui {
 						cols = 0;
 					} else if (rune.Value != '\r') {
 						cols++;
-						var rw = ((Rune)rune).GetColumns ();
+						var rw = 0;
-						if (rw > 0) {
+						if (rune.Value == '\t') {
-							rw--;
+							rw += tabWidth - 1;
+						} else {
+							rw = ((Rune)rune).GetColumns ();
+							if (rw > 0) {
+								rw--;
+							} else if (rw == 0) {
+								cols--;
+							}
 						}
 						cols += rw;
 					}
@@ -822,10 +860,18 @@ namespace Terminal.Gui {
 						cw = 1;
 					} else if (rune.Value != '\r') {
 						rows++;
-						var rw = ((Rune)rune).GetColumns ();
+						var rw = 0;
-						if (cw < rw) {
+						if (rune.Value == '\t') {
-							cw = rw;
+							rw += tabWidth - 1;
-							vw++;
+							rows += rw;
+						} else {
+							rw = ((Rune)rune).GetColumns ();
+							if (rw == 0) {
+								rows--;
+							} else if (cw < rw) {
+								cw = rw;
+								vw++;
+							}
 						}
 					}
 				}
@@ -954,7 +1000,7 @@ namespace Terminal.Gui {
 		#endregion // Static Members
 
 		List<string> _lines = new List<string> ();
-		string _text;
+		string _text = null;
 		TextAlignment _textAlignment;
 		VerticalTextAlignment _textVerticalAlignment;
 		TextDirection _textDirection;
@@ -973,13 +1019,17 @@ namespace Terminal.Gui {
 		public virtual string Text {
 			get => _text;
 			set {
+				if (AutoSize || (_text == null && value != null && Size.IsEmpty)) {
+					Size = CalcRect (0, 0, value, _textDirection, TabWidth).Size;
+				}
+
 				_text = value;
 
-				if (_text != null && _text.GetRuneCount () > 0 && (Size.Width == 0 || Size.Height == 0 || Size.Width != _text.GetColumns ())) {
+				//if (_text != null && _text.GetRuneCount () > 0 && (Size.Width == 0 || Size.Height == 0 || Size.Width != _text.GetColumns ())) {
-					// Provide a default size (width = length of longest line, height = 1)
+				//	// Provide a default size (width = length of longest line, height = 1)
-					// TODO: It might makes more sense for the default to be width = length of first line?
+				//	// TODO: It might makes more sense for the default to be width = length of first line?
-					Size = new Size (TextFormatter.MaxWidth (Text, int.MaxValue), 1);
+				//	Size = new Size (TextFormatter.MaxWidth (Text, int.MaxValue), 1);
-				}
+				//}
 
 				NeedsFormat = true;
 			}
@@ -1194,7 +1244,7 @@ namespace Terminal.Gui {
 					if (IsVerticalDirection (_textDirection)) {
 						var colsWidth = GetSumMaxCharWidth (shown_text, 0, 1);
 						_lines = Format (shown_text, Size.Height, _textVerticalAlignment == VerticalTextAlignment.Justified, Size.Width > colsWidth,
-							PreserveTrailingSpaces, 0, _textDirection);
+							PreserveTrailingSpaces, TabWidth, _textDirection);
 						if (!AutoSize) {
 							colsWidth = GetMaxColsForWidth (_lines, Size.Width);
 							if (_lines.Count > colsWidth) {
@@ -1203,7 +1253,7 @@ namespace Terminal.Gui {
 						}
 					} else {
 						_lines = Format (shown_text, Size.Width, _textAlignment == TextAlignment.Justified, Size.Height > 1,
-							PreserveTrailingSpaces, 0, _textDirection);
+							PreserveTrailingSpaces, TabWidth, _textDirection);
 						if (!AutoSize && _lines.Count > Size.Height) {
 							_lines.RemoveRange (Size.Height, _lines.Count - Size.Height);
 						}
@@ -1226,6 +1276,11 @@ namespace Terminal.Gui {
 		/// </remarks>
 		public bool NeedsFormat { get; set; }
 
+		/// <summary>
+		/// Gets or sets the number of columns used for a tab.
+		/// </summary>
+		public int TabWidth { get; set; } = 4;
+
 		/// <summary>
 		/// Causes the <see cref="TextFormatter"/> to reformat the text. 
 		/// </summary>
@@ -1375,31 +1430,64 @@ namespace Terminal.Gui {
 				var start = isVertical ? bounds.Top : bounds.Left;
 				var size = isVertical ? bounds.Height : bounds.Width;
 				var current = start + colOffset;
+				List<Point?> lastZeroWidthPos = null;
+				Rune rune = default;
+				Rune lastRuneUsed;
+				var zeroLengthCount = isVertical ? runes.Sum (r => r.GetColumns () == 0 ? 1 : 0) : 0;
 
-				for (var idx = (isVertical ? start - y : start - x) + colOffset; current < start + size; idx++) {
+				for (var idx = (isVertical ? start - y : start - x) + colOffset; current < start + size + zeroLengthCount; idx++) {
-					if (idx < 0 || x + current + colOffset < 0) {
+					lastRuneUsed = rune;
-						current++;
+					if (lastZeroWidthPos == null) {
-						continue;
+						if (idx < 0 || x + current + colOffset < 0) {
-					} else if (!fillRemaining && idx > runes.Length - 1) {
+							current++;
-						break;
+							continue;
+						} else if (!fillRemaining && idx > runes.Length - 1) {
+							break;
+						}
+						if ((!isVertical && current - start > maxBounds.Left + maxBounds.Width - bounds.X + colOffset)
+							|| (isVertical && idx > maxBounds.Top + maxBounds.Height - bounds.Y)) {
+
+							break;
+						}
 					}
-					if ((!isVertical && idx > maxBounds.Left + maxBounds.Width - bounds.X + colOffset)
+					//if ((!isVertical && idx > maxBounds.Left + maxBounds.Width - bounds.X + colOffset)
-						|| (isVertical && idx > maxBounds.Top + maxBounds.Height - bounds.Y))
+					//	|| (isVertical && idx > maxBounds.Top + maxBounds.Height - bounds.Y))
 
-						break;
+					//	break;
 
-					var rune = (Rune)' ';
+					rune = (Rune)' ';
 					if (isVertical) {
-						Application.Driver?.Move (x, current);
 						if (idx >= 0 && idx < runes.Length) {
 							rune = runes [idx];
 						}
+						if (lastZeroWidthPos == null) {
+							Application.Driver?.Move (x, current);
+						} else {
+							var foundIdx = lastZeroWidthPos.IndexOf (p => p.Value.Y == current);
+							if (foundIdx > -1) {
+								if (rune.IsCombiningMark ()) {
+									lastZeroWidthPos [foundIdx] = (new Point (lastZeroWidthPos [foundIdx].Value.X + 1, current));
+
+									Application.Driver?.Move (lastZeroWidthPos [foundIdx].Value.X, current);
+								} else if (!rune.IsCombiningMark () && lastRuneUsed.IsCombiningMark ()) {
+									current++;
+									Application.Driver?.Move (x, current);
+								} else {
+									Application.Driver?.Move (x, current);
+								}
+							} else {
+								Application.Driver?.Move (x, current);
+							}
+						}
 					} else {
 						Application.Driver?.Move (current, y);
 						if (idx >= 0 && idx < runes.Length) {
 							rune = runes [idx];
 						}
 					}
+
+					var runeWidth = GetRuneWidth (rune.GetColumns ());
+
 					if (HotKeyPos > -1 && idx == HotKeyPos) {
 						if ((isVertical && _textVerticalAlignment == VerticalTextAlignment.Justified) ||
 						(!isVertical && _textAlignment == TextAlignment.Justified)) {
@@ -1409,12 +1497,27 @@ namespace Terminal.Gui {
 						Application.Driver?.AddRune (rune);
 						Application.Driver?.SetAttribute (normalColor);
 					} else {
+						if (isVertical) {
+							if (runeWidth == 0) {
+								if (lastZeroWidthPos == null) {
+									lastZeroWidthPos = new List<Point?> ();
+								}
+								var foundIdx = lastZeroWidthPos.IndexOf (p => p.Value.Y == current);
+								if (foundIdx == -1) {
+									current--;
+									lastZeroWidthPos.Add ((new Point (x + 1, current)));
+								}
+								Application.Driver?.Move (x + 1, current);
+							}
+						}
+
 						Application.Driver?.AddRune (rune);
 					}
-					// BUGBUG: I think this is a bug. If rune is a combining mark current should not be incremented.
+
-					var runeWidth = rune.GetColumns (); //Math.Max (rune.GetColumns (), 1);
 					if (isVertical) {
-						current++;
+						if (runeWidth > 0) {
+							current++;
+						}
 					} else {
 						current += runeWidth;
 					}

UnitTests/Text/TextFormatterTests.cs

@@ -65,13 +65,23 @@ namespace Terminal.Gui.TextTests {
 			Assert.NotEmpty (tf.Lines);
 		}
 
-		[Fact]
+		[Theory]
-		public void TestSize_TextChange ()
+		[InlineData (TextDirection.LeftRight_TopBottom, false)]
+		[InlineData (TextDirection.TopBottom_LeftRight, true)]
+		public void TestSize_TextChange (TextDirection textDirection, bool autoSize)
 		{
-			var tf = new TextFormatter () { Text = "你" };
+			var tf = new TextFormatter () { Direction = textDirection, Text = "你", AutoSize = autoSize };
 			Assert.Equal (2, tf.Size.Width);
 			tf.Text = "你你";
-			Assert.Equal (4, tf.Size.Width);
+			if (autoSize) {
+				if (textDirection == TextDirection.LeftRight_TopBottom) {
+					Assert.Equal (4, tf.Size.Width);
+				} else {
+					Assert.Equal (2, tf.Size.Width);
+				}
+			} else {
+				Assert.Equal (2, tf.Size.Width);
+			}
 		}
 
 		[Fact]
@@ -620,21 +630,24 @@ namespace Terminal.Gui.TextTests {
 
 		[Theory]
 		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 51, 0, new string [] { "กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ" })]
-		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 50, -1, new string [] { "กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัา", "ำ" })]
+		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 50, -1, new string [] { "กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ" })]
 		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 46, -5, new string [] { "กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮ", "ฯะัาำ" })]
 		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 26, -25, new string [] { "กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบ", "ปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ" })]
 		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 17, -34, new string [] { "กขฃคฅฆงจฉชซฌญฎฏฐฑ", "ฒณดตถทธนบปผฝพฟภมย", "รฤลฦวศษสหฬอฮฯะัาำ" })]
 		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 13, -38, new string [] { "กขฃคฅฆงจฉชซฌญ", "ฎฏฐฑฒณดตถทธนบ", "ปผฝพฟภมยรฤลฦว", "ศษสหฬอฮฯะัาำ" })]
-		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 1, -50, new string [] { "ก", "ข", "ฃ", "ค", "ฅ", "ฆ", "ง", "จ", "ฉ", "ช", "ซ", "ฌ", "ญ", "ฎ", "ฏ", "ฐ", "ฑ", "ฒ", "ณ", "ด", "ต", "ถ", "ท", "ธ", "น", "บ", "ป", "ผ", "ฝ", "พ", "ฟ", "ภ", "ม", "ย", "ร", "ฤ", "ล", "ฦ", "ว", "ศ", "ษ", "ส", "ห", "ฬ", "อ", "ฮ", "ฯ", "ะ", "ั", "า", "ำ" })]
+		[InlineData ("กขฃคฅฆงจฉชซฌญฎฏฐฑฒณดตถทธนบปผฝพฟภมยรฤลฦวศษสหฬอฮฯะัาำ", 1, -50, new string [] { "ก", "ข", "ฃ", "ค", "ฅ", "ฆ", "ง", "จ", "ฉ", "ช", "ซ", "ฌ", "ญ", "ฎ", "ฏ", "ฐ", "ฑ", "ฒ", "ณ", "ด", "ต", "ถ", "ท", "ธ", "น", "บ", "ป", "ผ", "ฝ", "พ", "ฟ", "ภ", "ม", "ย", "ร", "ฤ", "ล", "ฦ", "ว", "ศ", "ษ", "ส", "ห", "ฬ", "อ", "ฮ", "ฯ", "ะั", "า", "ำ" })]
 		public void WordWrap_Unicode_SingleWordLine (string text, int maxWidth, int widthOffset, IEnumerable<string> resultLines)
 		{
 			List<string> wrappedLines;
 
+			var zeroWidth = text.EnumerateRunes ().Where (r => r.GetColumns () == 0);
+			Assert.Single (zeroWidth);
+			Assert.Equal ('ั', zeroWidth.ElementAt (0).Value);
 			Assert.Equal (maxWidth, text.GetRuneCount () + widthOffset);
 			var expectedClippedWidth = Math.Min (text.GetRuneCount (), maxWidth);
 			wrappedLines = TextFormatter.WordWrapText (text, maxWidth);
 			Assert.Equal (wrappedLines.Count, resultLines.Count ());
-			Assert.True (expectedClippedWidth >= (wrappedLines.Count > 0 ? wrappedLines.Max (l => l.GetRuneCount ()) : 0));
+			Assert.True (expectedClippedWidth >= (wrappedLines.Count > 0 ? wrappedLines.Max (l => l.GetRuneCount () + zeroWidth.Count () - 1 + widthOffset) : 0));
 			Assert.True (expectedClippedWidth >= (wrappedLines.Count > 0 ? wrappedLines.Max (l => l.GetColumns ()) : 0));
 			Assert.Equal (resultLines, wrappedLines);
 		}
@@ -1418,5 +1431,127 @@ namespace Terminal.Gui.TextTests {
 				Assert.Equal (expected, text [index].ToString ());
 			}
 		}
+
+		[Fact]
+		public void GetLengthThatFits_With_Combining_Runes ()
+		{
+			var text = "Les Mise\u0328\u0301rables";
+			Assert.Equal (16, TextFormatter.GetLengthThatFits (text, 14));
+		}
+
+		[Fact]
+		public void GetMaxColsForWidth_With_Combining_Runes ()
+		{
+			var text = new List<string> () { "Les Mis", "e\u0328\u0301", "rables" };
+			Assert.Equal (1, TextFormatter.GetMaxColsForWidth (text, 1));
+		}
+
+		[Fact]
+		public void GetSumMaxCharWidth_With_Combining_Runes ()
+		{
+			var text = "Les Mise\u0328\u0301rables";
+			Assert.Equal (1, TextFormatter.GetSumMaxCharWidth (text, 1, 1));
+		}
+
+		[Fact]
+		public void GetSumMaxCharWidth_List_With_Combining_Runes ()
+		{
+			var text = new List<string> () { "Les Mis", "e\u0328\u0301", "rables" };
+			Assert.Equal (1, TextFormatter.GetSumMaxCharWidth (text, 1, 1));
+		}
+
+		[Theory]
+		[InlineData (14, 1, TextDirection.LeftRight_TopBottom)]
+		[InlineData (1, 14, TextDirection.TopBottom_LeftRight)]
+		public void CalcRect_With_Combining_Runes (int width, int height, TextDirection textDirection)
+		{
+			var text = "Les Mise\u0328\u0301rables";
+			Assert.Equal (new Rect (0, 0, width, height), TextFormatter.CalcRect (0, 0, text, textDirection));
+		}
+
+		[Theory, AutoInitShutdown]
+		[InlineData (14, 1, TextDirection.LeftRight_TopBottom, "Les Misęrables")]
+		[InlineData (1, 14, TextDirection.TopBottom_LeftRight, "L\ne\ns\n \nM\ni\ns\nę\nr\na\nb\nl\ne\ns")]
+		[InlineData (4, 4, TextDirection.TopBottom_LeftRight, @"
+LMre
+eias
+ssb 
+ ęl ")]
+		public void Draw_With_Combining_Runes (int width, int height, TextDirection textDirection, string expected)
+		{
+			var text = "Les Mise\u0328\u0301rables";
+
+			var tf = new TextFormatter ();
+			tf.Direction = textDirection;
+			tf.Text = text;
+
+			if (textDirection == TextDirection.LeftRight_TopBottom) {
+				Assert.Equal (new Size (width, height), tf.Size);
+			} else {
+				Assert.Equal (new Size (1, text.GetColumns ()), tf.Size);
+				tf.Size = new Size (width, height);
+			}
+			tf.Draw (new Rect (0, 0, width, height), new Attribute (ColorName.White, ColorName.Black), new Attribute (ColorName.Blue, ColorName.Black));
+			TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
+		}
+
+		[Theory, AutoInitShutdown]
+		[InlineData (17, 1, TextDirection.LeftRight_TopBottom, 4, "This is a     Tab")]
+		[InlineData (1, 17, TextDirection.TopBottom_LeftRight, 4, "T\nh\ni\ns\n \ni\ns\n \na\n \n \n \n \n \nT\na\nb")]
+		[InlineData (13, 1, TextDirection.LeftRight_TopBottom, 0, "This is a Tab")]
+		[InlineData (1, 13, TextDirection.TopBottom_LeftRight, 0, "T\nh\ni\ns\n \ni\ns\n \na\n \nT\na\nb")]
+		public void TabWith_PreserveTrailingSpaces_False (int width, int height, TextDirection textDirection, int tabWidth, string expected)
+		{
+			var text = "This is a \tTab";
+			var tf = new TextFormatter ();
+			tf.Direction = textDirection;
+			tf.TabWidth = tabWidth;
+			tf.Text = text;
+
+			Assert.False (tf.WordWrap);
+			Assert.False (tf.PreserveTrailingSpaces);
+			Assert.Equal (new Size (width, height), tf.Size);
+			tf.Draw (new Rect (0, 0, width, height), new Attribute (ColorName.White, ColorName.Black), new Attribute (ColorName.Blue, ColorName.Black));
+			TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
+		}
+
+		[Theory, AutoInitShutdown]
+		[InlineData (17, 1, TextDirection.LeftRight_TopBottom, 4, "This is a     Tab")]
+		[InlineData (1, 17, TextDirection.TopBottom_LeftRight, 4, "T\nh\ni\ns\n \ni\ns\n \na\n \n \n \n \n \nT\na\nb")]
+		[InlineData (13, 1, TextDirection.LeftRight_TopBottom, 0, "This is a Tab")]
+		[InlineData (1, 13, TextDirection.TopBottom_LeftRight, 0, "T\nh\ni\ns\n \ni\ns\n \na\n \nT\na\nb")]
+		public void TabWith_PreserveTrailingSpaces_True (int width, int height, TextDirection textDirection, int tabWidth, string expected)
+		{
+			var text = "This is a \tTab";
+			var tf = new TextFormatter ();
+			tf.Direction = textDirection;
+			tf.TabWidth = tabWidth;
+			tf.PreserveTrailingSpaces = true;
+			tf.Text = text;
+
+			Assert.False (tf.WordWrap);
+			Assert.Equal (new Size (width, height), tf.Size);
+			tf.Draw (new Rect (0, 0, width, height), new Attribute (ColorName.White, ColorName.Black), new Attribute (ColorName.Blue, ColorName.Black));
+			TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
+		}
+
+		[Theory, AutoInitShutdown]
+		[InlineData (17, 1, TextDirection.LeftRight_TopBottom, 4, "This is a     Tab")]
+		[InlineData (1, 17, TextDirection.TopBottom_LeftRight, 4, "T\nh\ni\ns\n \ni\ns\n \na\n \n \n \n \n \nT\na\nb")]
+		[InlineData (13, 1, TextDirection.LeftRight_TopBottom, 0, "This is a Tab")]
+		[InlineData (1, 13, TextDirection.TopBottom_LeftRight, 0, "T\nh\ni\ns\n \ni\ns\n \na\n \nT\na\nb")]
+		public void TabWith_WordWrap_True (int width, int height, TextDirection textDirection, int tabWidth, string expected)
+		{
+			var text = "This is a \tTab";
+			var tf = new TextFormatter ();
+			tf.Direction = textDirection;
+			tf.TabWidth = tabWidth;
+			tf.WordWrap = true;
+			tf.Text = text;
+
+			Assert.Equal (new Size (width, height), tf.Size);
+			tf.Draw (new Rect (0, 0, width, height), new Attribute (ColorName.White, ColorName.Black), new Attribute (ColorName.Blue, ColorName.Black));
+			TestHelpers.AssertDriverContentsWithFrameAre (expected, output);
+		}
 	}
 }