C# LayoutWrapper类代码示例

		protected override LayoutWrapper RenderLine (long line)
		{
			var layout = new TextLayout (Editor);
			layout.Font = Editor.Options.Font;
			StringBuilder sb = new StringBuilder ();
			long startOffset = line * Editor.BytesInRow;
			long endOffset   = System.Math.Min (startOffset + Editor.BytesInRow, Data.Length);
			byte[] lineBytes = Data.GetBytes (startOffset, (int)(endOffset - startOffset));
			for (int i = 0; i < lineBytes.Length; i++) {
				byte b = lineBytes[i];
				char ch = (char)b;
				if (b < 128 && (Char.IsLetterOrDigit (ch) || Char.IsPunctuation (ch))) {
					sb.Append (ch);
				} else {
					sb.Append (".");
				}
			}
			
			layout.Text = sb.ToString ();
			Margin.LayoutWrapper result = new LayoutWrapper (layout);
			if (Data.IsSomethingSelected) {
				ISegment selection = Data.MainSelection.Segment;
				HandleSelection (selection.Offset, selection.EndOffset, startOffset, endOffset, null, delegate(long start, long end) {
					result.Layout.SetForeground (Style.Selection, (int)(start - startOffset), (int)(end - start));
					result.Layout.SetBackground (Style.SelectionBg, (int)(start - startOffset), (int)(end - start));
				});
			}
			return result;
		}

		protected override LayoutWrapper RenderLine (long line)
		{
			Pango.Layout layout = new Pango.Layout (Editor.PangoContext);
			layout.FontDescription = Editor.Options.Font;
			StringBuilder sb = new StringBuilder ();
			long startOffset = line * Editor.BytesInRow;
			long endOffset   = System.Math.Min (startOffset + Editor.BytesInRow, Data.Length);
			byte[] lineBytes = Data.GetBytes (startOffset, (int)(endOffset - startOffset));
			for (int i = 0; i < lineBytes.Length; i++) {
				byte b = lineBytes[i];
				char ch = (char)b;
				if (b < 128 && (Char.IsLetterOrDigit (ch) || Char.IsPunctuation (ch))) {
					sb.Append (ch);
				} else {
					sb.Append (".");
				}
			}
			
			layout.SetText (sb.ToString ());
			char[] lineChars = layout.Text.ToCharArray ();
			Margin.LayoutWrapper result = new LayoutWrapper (layout);
			uint curIndex = 0, byteIndex = 0;
			if (Data.IsSomethingSelected) {
				ISegment selection = Data.MainSelection.Segment;
				HandleSelection (selection.Offset, selection.EndOffset, startOffset, endOffset, null, delegate(long start, long end) {
					Pango.AttrForeground selectedForeground = new Pango.AttrForeground (Style.Selection.Red, 
					                                                                    Style.Selection.Green, 
					                                                                    Style.Selection.Blue);
					selectedForeground.StartIndex = TranslateToUTF8Index (lineChars, (uint)(start - startOffset), ref curIndex, ref byteIndex);
					selectedForeground.EndIndex = TranslateToUTF8Index (lineChars, (uint)(end - startOffset), ref curIndex, ref byteIndex);
					
					result.Add (selectedForeground);
					
					Pango.AttrBackground attrBackground = new Pango.AttrBackground (Style.SelectionBg.Red, 
					                                                                Style.SelectionBg.Green, 
					                                                                Style.SelectionBg.Blue);
					attrBackground.StartIndex = selectedForeground.StartIndex;
					attrBackground.EndIndex = selectedForeground.EndIndex;
					result.Add (attrBackground);

				});
			}
			result.SetAttributes ();
			return result;
		}

		void InnerDecorateTabsAndSpaces (Cairo.Context ctx, LayoutWrapper layout, int offset, double x, double y, int selectionStart, int selectionEnd, char spaceOrTab)
		{
			var chars = layout.LineChars;
			if (Array.IndexOf (chars, spaceOrTab) == -1)
				return;

			uint curIndex = 0, byteIndex = 0;
			bool first = true, oldSelected = false;
			var curchunk = layout.Chunks != null ? layout.Chunks.FirstOrDefault () : null;

			var dotThickness = textEditor.Options.Zoom * 2;
			var textEditorWidth = textEditor.Allocation.Width;

			//Get 1st visible character index from left based on HAdjustment
			int index, trailing;
			layout.Layout.XyToIndex ((int)textEditor.HAdjustment.Value, 0, out index, out trailing);

			double ypos;
			if (spaceOrTab == ' ') {
				ypos = System.Math.Floor (y + (LineHeight - dotThickness) / 2);
			} else {
				ypos = 0.5 + System.Math.Floor (y + LineHeight / 2);
			}

			var showOnlySelected = textEditor.Options.ShowWhitespaces != ShowWhitespaces.Always;

			var lastColor = new Cairo.Color ();
			bool firstDraw = true;
			var foregroundColor = ColorStyle.PlainText.Foreground;

			int lastIndex = -1;
			int lastPosX = 0;

			for (int i = index; i < chars.Length; i++) {
				if (spaceOrTab != chars [i])
					continue;

				bool selected = selectionStart <= offset + i && offset + i < selectionEnd;
				if (first || oldSelected != selected) {
					first = false;
					oldSelected = selected;
				}

				if (showOnlySelected && !selected)
					continue;
				int line, posX;
				if (lastIndex == i) {
					posX = lastPosX;
				} else {
					layout.Layout.IndexToLineX ((int)TranslateToUTF8Index (chars, (uint)i, ref curIndex, ref byteIndex), false, out line, out posX);
				}
				double xpos = x + posX / Pango.Scale.PangoScale;
				if (xpos > textEditorWidth)
					break;
				layout.Layout.IndexToLineX ((int)TranslateToUTF8Index (chars, (uint)i + 1, ref curIndex, ref byteIndex), false, out line, out posX);
				lastPosX = posX;
				lastIndex = i + 1;
				double xpos2 = x + posX / Pango.Scale.PangoScale;
				var col = new Cairo.Color (0, 0, 0);
				if (SelectionColor.TransparentForeground) {
					while (curchunk != null && curchunk.EndOffset < offset + i)
						curchunk = curchunk.Next;
					if (curchunk != null && curchunk.SpanStack.Count > 0 && curchunk.SpanStack.Peek ().Color != "Plain Text") {
						var chunkStyle = ColorStyle.GetChunkStyle (curchunk.SpanStack.Peek ().Color);
						if (chunkStyle != null)
							col = ColorStyle.GetForeground (chunkStyle);
					} else {
						col = foregroundColor;
					}
				} else {
					col = selected ? SelectionColor.Foreground : foregroundColor;
				}

				if (firstDraw || (lastColor.R != col.R && lastColor.G != col.G && lastColor.B != col.B)) {
					ctx.SetSourceRGBA (col.R, col.G, col.B, whitespaceMarkerAlpha);
					lastColor = col;
					firstDraw = false;
				}

				if (spaceOrTab == ' ') {
					ctx.Rectangle (xpos + (xpos2 - xpos - dotThickness) / 2, ypos, dotThickness, dotThickness);
				} else {
					ctx.MoveTo (0.5 + xpos, ypos);
					ctx.LineTo (0.5 + xpos2 - charWidth / 2, ypos);
				}
			}
			if (!firstDraw) {//Atleast one draw was called
				if (spaceOrTab == ' ') {
					ctx.Fill ();
				} else {
					ctx.Stroke ();
				}
			}
		}

		public LayoutWrapper CreateLinePartLayout (ISyntaxMode mode, LineSegment line, int logicalRulerColumn, int offset, int length, int selectionStart, int selectionEnd)
		{
			bool containsPreedit = textEditor.ContainsPreedit (offset, length);
			LayoutDescriptor descriptor;
			if (!containsPreedit && layoutDict.TryGetValue (line, out descriptor)) {
				bool isInvalid;
				if (descriptor.Equals (line, offset, length, selectionStart, selectionEnd, out isInvalid) && descriptor.Layout != null) {
					return descriptor.Layout;
				}
				descriptor.Dispose ();
				layoutDict.Remove (line);
			}
			var wrapper = new LayoutWrapper (PangoUtil.CreateLayout (textEditor));
			wrapper.IsUncached = containsPreedit;

			if (logicalRulerColumn < 0)
				logicalRulerColumn = line.GetLogicalColumn (textEditor.GetTextEditorData (), textEditor.Options.RulerColumn);
			var atts = new FastPangoAttrList ();
			wrapper.Layout.Alignment = Pango.Alignment.Left;
			wrapper.Layout.FontDescription = textEditor.Options.Font;
			wrapper.Layout.Tabs = tabArray;
			StringBuilder textBuilder = new StringBuilder ();
			var chunks = GetCachedChunks (mode, Document, textEditor.ColorStyle, line, offset, length);
			foreach (var chunk in chunks) {
				try {
					textBuilder.Append (Document.GetTextAt (chunk));
				} catch {
					Console.WriteLine (chunk);
				}
			}
			var spanStack = line.StartSpan;
			int lineOffset = line.Offset;
			string lineText = textBuilder.ToString ();
			uint preeditLength = 0;
			
			if (containsPreedit) {
				lineText = lineText.Insert (textEditor.preeditOffset - offset, textEditor.preeditString);
				preeditLength = (uint)textEditor.preeditString.Length;
			}
			char[] lineChars = lineText.ToCharArray ();
			//int startOffset = offset, endOffset = offset + length;
			uint curIndex = 0, byteIndex = 0;
			uint curChunkIndex = 0, byteChunkIndex = 0;
			
			uint oldEndIndex = 0;
			foreach (Chunk chunk in chunks) {
				ChunkStyle chunkStyle = chunk != null ? textEditor.ColorStyle.GetChunkStyle (chunk) : null;
				spanStack = chunk.SpanStack ?? spanStack;
				foreach (TextMarker marker in line.Markers)
					chunkStyle = marker.GetStyle (chunkStyle);

				if (chunkStyle != null) {
					//startOffset = chunk.Offset;
					//endOffset = chunk.EndOffset;

					uint startIndex = (uint)(oldEndIndex);
					uint endIndex = (uint)(startIndex + chunk.Length);
					oldEndIndex = endIndex;

					HandleSelection (lineOffset, logicalRulerColumn, selectionStart, selectionEnd, chunk.Offset, chunk.EndOffset, delegate(int start, int end) {
						if (containsPreedit) {
							if (textEditor.preeditOffset < start)
								start += (int)preeditLength;
							if (textEditor.preeditOffset < end)
								end += (int)preeditLength;
						}
						var si = TranslateToUTF8Index (lineChars, (uint)(startIndex + start - chunk.Offset), ref curIndex, ref byteIndex);
						var ei = TranslateToUTF8Index (lineChars, (uint)(startIndex + end - chunk.Offset), ref curIndex, ref byteIndex);
						atts.AddForegroundAttribute (chunkStyle.Color, si, ei);
						
						if (!chunkStyle.TransparentBackround && GetPixel (ColorStyle.Default.BackgroundColor) != GetPixel (chunkStyle.BackgroundColor)) {
							wrapper.AddBackground (chunkStyle.CairoBackgroundColor, (int)si, (int)ei);
						} else if (chunk.SpanStack != null && ColorStyle != null) {
							foreach (var span in chunk.SpanStack) {
								if (span == null)
									continue;
								var spanStyle = ColorStyle.GetChunkStyle (span.Color);
								if (!spanStyle.TransparentBackround && GetPixel (ColorStyle.Default.BackgroundColor) != GetPixel (spanStyle.BackgroundColor)) {
									wrapper.AddBackground (spanStyle.CairoBackgroundColor, (int)si, (int)ei);
									break;
								}
							}
						}
					}, delegate(int start, int end) {
						if (containsPreedit) {
							if (textEditor.preeditOffset < start)
								start += (int)preeditLength;
							if (textEditor.preeditOffset < end)
								end += (int)preeditLength;
						}
						var si = TranslateToUTF8Index (lineChars, (uint)(startIndex + start - chunk.Offset), ref curIndex, ref byteIndex);
						var ei = TranslateToUTF8Index (lineChars, (uint)(startIndex + end - chunk.Offset), ref curIndex, ref byteIndex);
						atts.AddForegroundAttribute (SelectionColor.Color, si, ei);
						if (!wrapper.StartSet)
							wrapper.SelectionStartIndex = (int)si;
						wrapper.SelectionEndIndex = (int)ei;
					});

					var translatedStartIndex = TranslateToUTF8Index (lineChars, (uint)startIndex, ref curChunkIndex, ref byteChunkIndex);
					var translatedEndIndex = TranslateToUTF8Index (lineChars, (uint)endIndex, ref curChunkIndex, ref byteChunkIndex);
//.........这里部分代码省略.........

		void DrawLinePart (Cairo.Context cr, LineSegment line, int lineNumber, int logicalRulerColumn, int offset, int length, ref double pangoPosition, ref bool isSelectionDrawn, double y, double maxX)
		{
			ISyntaxMode mode = Document.SyntaxMode != null && textEditor.Options.EnableSyntaxHighlighting ? Document.SyntaxMode : new SyntaxMode (Document);
			int selectionStart;
			int selectionEnd;
			if (this.HideSelection) {
				selectionStart = selectionEnd = -1;
			} else {
				GetSelectionOffsets (line, out selectionStart, out selectionEnd);
			}

			// ---- new renderer
			LayoutWrapper layout = CreateLinePartLayout (mode, line, logicalRulerColumn, offset, length, selectionStart, selectionEnd);
			int lineOffset = line.Offset;
			double width = layout.PangoWidth / Pango.Scale.PangoScale;
			double xPos = pangoPosition / Pango.Scale.PangoScale;

			//		if (!(HighlightCaretLine || textEditor.Options.HighlightCaretLine) || Document.GetLine(Caret.Line) != line) {
			foreach (var bg in layout.BackgroundColors) {
				int x1, x2;
				x1 = layout.Layout.IndexToPos (bg.FromIdx).X;
				x2 = layout.Layout.IndexToPos (bg.ToIdx).X;
				DrawRectangleWithRuler (cr, xPos + textEditor.HAdjustment.Value - TextStartPosition,
						new Cairo.Rectangle ((x1 + pangoPosition) / Pango.Scale.PangoScale, y, (x2 - x1) / Pango.Scale.PangoScale + 1, LineHeight),
						bg.Color, true);
			}
			//		}

			bool drawBg = true;
			bool drawText = true;
			foreach (TextMarker marker in line.Markers) {
				IBackgroundMarker bgMarker = marker as IBackgroundMarker;
				if (bgMarker == null || !marker.IsVisible)
					continue;
				isSelectionDrawn |= (marker.Flags & TextMarkerFlags.DrawsSelection) == TextMarkerFlags.DrawsSelection;
				drawText &= bgMarker.DrawBackground (textEditor, cr, layout, selectionStart, selectionEnd, offset, offset + length, y, xPos, xPos + width, ref drawBg);
			}

			if (DecorateLineBg != null)
				DecorateLineBg (cr, layout, offset, length, xPos, y, selectionStart, selectionEnd);
			
			if ((HighlightCaretLine || textEditor.Options.HighlightCaretLine) && Caret.Line == lineNumber)
				DrawCaretLineMarker (cr, xPos, y, layout.PangoWidth / Pango.Scale.PangoScale);

			if (!isSelectionDrawn && (layout.StartSet || selectionStart == offset + length)) {
				double startX;
				double endX;

				if (selectionStart != offset + length) {
					var start = layout.Layout.IndexToPos ((int)layout.SelectionStartIndex);
					startX = start.X / Pango.Scale.PangoScale;
					var end = layout.Layout.IndexToPos ((int)layout.SelectionEndIndex);
					endX = end.X / Pango.Scale.PangoScale;
				} else {
					startX = width;
					endX = startX;
				}

				if (textEditor.MainSelection.SelectionMode == SelectionMode.Block && startX == endX) {
					endX = startX + 2;
				}
				DrawRectangleWithRuler (cr, xPos + textEditor.HAdjustment.Value - TextStartPosition, new Cairo.Rectangle (xPos + startX, y, endX - startX, LineHeight), this.SelectionColor.CairoBackgroundColor, true);
			}

			// highlight search results
			TextSegment firstSearch;
			int o = offset;
			uint curIndex = 0, byteIndex = 0;
			if (textEditor.HighlightSearchPattern) {
				while (!(firstSearch = GetFirstSearchResult (o, offset + length)).IsInvalid) {
					double x = pangoPosition;
					HandleSelection (lineOffset, logicalRulerColumn, selectionStart, selectionEnd, System.Math.Max (lineOffset, firstSearch.Offset), System.Math.Min (lineOffset + line.Length, firstSearch.EndOffset), delegate(int start, int end) {
						uint startIndex = (uint)(start - offset);
						uint endIndex = (uint)(end - offset);
						if (startIndex < endIndex && endIndex <= layout.LineChars.Length) {
							uint startTranslated = TranslateToUTF8Index (layout.LineChars, startIndex, ref curIndex, ref byteIndex);
							uint endTranslated = TranslateToUTF8Index (layout.LineChars, endIndex, ref curIndex, ref byteIndex);
							
							int l, x1, x2;
							layout.Layout.IndexToLineX ((int)startTranslated, false, out l, out x1);
							layout.Layout.IndexToLineX ((int)endTranslated, false, out l, out x2);
							x1 += (int)x;
							x2 += (int)x;
							x1 /= (int)Pango.Scale.PangoScale;
							x2 /= (int)Pango.Scale.PangoScale;
	
							cr.Color = MainSearchResult.IsInvalid || MainSearchResult.Offset != firstSearch.Offset ? ColorStyle.SearchTextBg : ColorStyle.SearchTextMainBg;
							FoldingScreenbackgroundRenderer.DrawRoundRectangle (cr, true, true, x1, y, System.Math.Min (10, width) * textEditor.Options.Zoom, x2 - x1, LineHeight);
							cr.Fill ();
						}
					}, null);
	
					o = System.Math.Max (firstSearch.EndOffset, o + 1);
				}
			}
			
			cr.Save ();
			cr.Translate (xPos, y);
			cr.ShowLayout (layout.Layout);
			cr.Restore ();
//.........这里部分代码省略.........

			bool ConsumeLayout (LayoutWrapper layoutWrapper, int xp, int yp)
			{
				int trailing;
				bool isInside = layoutWrapper.Layout.XyToIndex (xp, yp, out index, out trailing);

				if (isInside) {
					int lineNr;
					int xp1, xp2;
					layoutWrapper.Layout.IndexToLineX (index, false, out lineNr, out xp1);
					layoutWrapper.Layout.IndexToLineX (index + 1, false, out lineNr, out xp2);
					index = TranslateIndexToUTF8 (layoutWrapper.Layout.Text, index);

					if (snapCharacters && !IsNearX1 (xp, xp1, xp2))
						index++;
					return true;
				}
				index = line.Length;
				return false;
			}

			public LayoutDescriptor (DocumentLine line, int offset, int length, LayoutWrapper layout, int selectionStart, int selectionEnd) : base(line, offset, length)
			{
				this.Layout = layout;
				if (selectionEnd >= 0) {
					this.SelectionStart = selectionStart;
					this.SelectionEnd = selectionEnd;
				}
			}

		void DrawIndent (Cairo.Context cr, LayoutWrapper layout, DocumentLine line, double xPos, double y)
		{
			if (!textEditor.Options.DrawIndentationMarkers)
				return;
			if (line.Length == 0) {
				var nextLine = line.NextLine;
				while (nextLine != null && nextLine.Length == 0)
					nextLine = nextLine.NextLine;
				if (nextLine != null)
					layout = GetLayout (nextLine);
			}
			if (layout.IndentSize == 0)
				return;
			cr.Save ();
			var dotted = new [] { textEditor.Options.Zoom };
			cr.SetDash (dotted, (int)y + textEditor.VAdjustment.Value);
			var top = y;
			var bottom = y + LineHeight;
			if (Caret.Line == line.LineNumber && textEditor.Options.HighlightCaretLine) {
				top += textEditor.Options.Zoom;
				bottom -= textEditor.Options.Zoom;
			}
			for (int i = 0; i < layout.IndentSize; i += textEditor.Options.IndentationSize) {
				var x = System.Math.Floor (xPos + i * charWidth);
				cr.MoveTo (x + 0.5, top);
				cr.LineTo (x + 0.5, bottom);

				cr.Color = ColorStyle.IndentationGuide.Color;
				cr.Stroke ();
			}
			cr.Restore ();
		}

		void DecorateTabsAndSpaces (Cairo.Context ctx, LayoutWrapper layout, int offset, int length, double xPos, double y, int selectionStart, int selectionEnd)
		{
			uint curIndex = 0, byteIndex = 0;
			bool first = true, oldSelected = false;
			int index, trailing;
			layout.Layout.XyToIndex ((int)textEditor.HAdjustment.Value, 0, out index, out trailing);
			var curchunk = layout.Chunks != null ? layout.Chunks.FirstOrDefault () : null;
			for (int i = index; i < layout.LineChars.Length; i++) {
				char ch = layout.LineChars [i];
				if (ch != ' ' && ch != '\t')
					continue;
				if (ch == ' ' && !textEditor.Options.IncludeWhitespaces.HasFlag (IncludeWhitespaces.Space))
					continue;
				if (ch == '\t' && !textEditor.Options.IncludeWhitespaces.HasFlag (IncludeWhitespaces.Tab))
					continue;
				bool selected = selectionStart <= offset + i && offset + i < selectionEnd;
				if (first || oldSelected != selected) {
					first = false;
					oldSelected = selected;
				}
				if (!selected && textEditor.Options.ShowWhitespaces != ShowWhitespaces.Always)
					continue;
				Pango.Rectangle pos = layout.Layout.IndexToPos ((int)TranslateToUTF8Index (layout.LineChars, (uint)i, ref curIndex, ref byteIndex));
				double xpos = xPos + pos.X / Pango.Scale.PangoScale;
				if (xpos > textEditor.Allocation.Width)
					break;
				Pango.Rectangle pos2 = layout.Layout.IndexToPos ((int)TranslateToUTF8Index (layout.LineChars, (uint)i + 1, ref curIndex, ref byteIndex));
				double xpos2 = xPos + pos2.X / Pango.Scale.PangoScale;
				Cairo.Color col = new Cairo.Color (0, 0, 0);
				if (SelectionColor.TransparentForeground) {
					while (curchunk != null && curchunk.EndOffset < offset + i)
						curchunk = curchunk.Next;
					if (curchunk != null && curchunk.SpanStack.Count > 0 && curchunk.SpanStack.Peek ().Color != "Plain Text") {
						var chunkStyle = ColorStyle.GetChunkStyle (curchunk.SpanStack.Peek ().Color);
						if (chunkStyle != null)
							col = ColorStyle.GetForeground (chunkStyle);
					} else {
						col = ColorStyle.PlainText.Foreground;
					}
				} else {
					col = selected ? SelectionColor.Foreground : col = ColorStyle.PlainText.Foreground;
				}
				ctx.Color = new Cairo.Color (col.R, col.G, col.B, whitespaceMarkerAlpha);

				if (ch == '\t') {
					DrawTabMarker (ctx, selected, xpos, xpos2, y);
				} else {
					DrawSpaceMarker (ctx, selected, xpos, xpos2, y);
				}
			}
		}

		void DecorateMatchingBracket (Gdk.Drawable win, LayoutWrapper layout, int offset, int length, int xPos, int y, int selectionStart, int selectionEnd)
		{
			uint curIndex = 0, byteIndex = 0;
			if (offset <= highlightBracketOffset && highlightBracketOffset <= offset + length) {
				int index = highlightBracketOffset - offset;
				Pango.Rectangle rect = layout.Layout.IndexToPos ((int)TranslateToUTF8Index (layout.LineChars, (uint)index, ref curIndex, ref byteIndex));
				
				Gdk.Rectangle bracketMatch = new Gdk.Rectangle (xPos + (int)(rect.X / Pango.Scale.PangoScale), y, (int)(rect.Width / Pango.Scale.PangoScale) - 1, (int)(rect.Height / Pango.Scale.PangoScale) - 1);
				if (BackgroundRenderer == null)
					win.DrawRectangle (GetGC (this.ColorStyle.BracketHighlightRectangle.BackgroundColor), true, bracketMatch);
				
				win.DrawRectangle (GetGC (this.ColorStyle.BracketHighlightRectangle.Color), false, bracketMatch);
			}
		}

		void DecorateTabs (Gdk.Drawable win, LayoutWrapper layout, int offset, int length, int xPos, int y, int selectionStart, int selectionEnd)
		{
			uint curIndex = 0, byteIndex = 0;
			for (int i = 0; i < layout.LineChars.Length; i++) {
				if (layout.LineChars[i] == '\t') {
					Pango.Rectangle pos = layout.Layout.IndexToPos ((int)TranslateToUTF8Index (layout.LineChars, (uint)i, ref curIndex, ref byteIndex));
					int xpos = pos.X;
					DrawTabMarker (win, selectionStart <= offset + i && offset + i < selectionEnd, xPos + xpos / 1024, y);
				}
			}
		}

		void DecorateTabsAndSpaces (Cairo.Context ctx, LayoutWrapper layout, int offset, int length, double xPos, double y, int selectionStart, int selectionEnd)
		{
			uint curIndex = 0, byteIndex = 0;
			bool first = true, oldSelected = false;
			for (int i = 0; i < layout.LineChars.Length; i++) {
				char ch = layout.LineChars[i];
				if (ch != ' ' && ch != '\t')
					continue;
				bool selected = selectionStart <= offset + i && offset + i < selectionEnd;
				if (first || oldSelected != selected) {
					ctx.Color = selected ? SelectionColor.CairoColor : ColorStyle.WhitespaceMarker;
					first = false;
					oldSelected = selected;
				}
				Pango.Rectangle pos = layout.Layout.IndexToPos ((int)TranslateToUTF8Index (layout.LineChars, (uint)i, ref curIndex, ref byteIndex));
				int xpos = pos.X;
				if (ch == '\t') {
					DrawTabMarker (ctx, selected, xPos + xpos / Pango.Scale.PangoScale, y);
				} else {
					DrawSpaceMarker (ctx, selected, xPos + xpos / Pango.Scale.PangoScale, y);
				}
			}
		}

		protected override LayoutWrapper RenderLine (long line)
		{
			var layout = new TextLayout (Editor);
			layout.Font = Editor.Options.Font;
			StringBuilder sb = new StringBuilder ();
			long startOffset = line * Editor.BytesInRow;
			long endOffset   = System.Math.Min (startOffset + Editor.BytesInRow, Data.Length);
			byte[] lineBytes = Data.GetBytes (startOffset, (int)(endOffset - startOffset));
			switch (Editor.Options.StringRepresentationType) {
			case StringRepresentationTypes.ASCII:
				for (int i = 0; i < lineBytes.Length; i++) {
					byte b = lineBytes [i];
					char ch = (char)b;
					if (!char.IsControl (ch)) {
						sb.Append (ch);
					} else {
						sb.Append (".");
					}
				}
				break;
			case StringRepresentationTypes.UTF16:
				for (int i = 0; i < lineBytes.Length - 1; i += 2) {

					char ch = Encoding.Unicode.GetChars (lineBytes, i, 2) [0];
					if (char.IsLetterOrDigit (ch) || char.IsWhiteSpace (ch) || char.IsSymbol (ch) || char.IsPunctuation (ch))
						sb.Append (ch);
					else
						sb.Append (".");
				}
				break;
			default:
				throw new NotImplementedException (Editor.Options.StringRepresentationType.ToString ());
			}
			
			layout.Text = sb.ToString ();
			Margin.LayoutWrapper result = new LayoutWrapper (layout);
			if (Data.IsSomethingSelected) {
				ISegment selection = Data.MainSelection.Segment;
				HandleSelection (selection.Offset, selection.EndOffset, startOffset, endOffset, this, new LayoutOffsetPair (startOffset, result.Layout), null, OnSelected);
			}
			return result;
		}

		protected override LayoutWrapper RenderLine (long line)
		{
			Pango.Layout layout = new Pango.Layout (Editor.PangoContext);
			layout.FontDescription = Editor.Options.Font;
			layout.Tabs = tabArray;
			StringBuilder sb = new StringBuilder ();
			long startOffset = line * Editor.BytesInRow;
			long endOffset   = System.Math.Min (startOffset + Editor.BytesInRow, Data.Length);
			byte[] lineBytes = Data.GetBytes (startOffset, (int)(endOffset - startOffset));
			for (int i = 0; i < lineBytes.Length; i++) {
				sb.Append (string.Format ("{0:X2}", lineBytes[i]));
				if (i % Editor.Options.GroupBytes == 0)
					sb.Append ("\t");
			}
			
			layout.SetText (sb.ToString ());
			char[] lineChars = sb.ToString ().ToCharArray ();
			Margin.LayoutWrapper result = new LayoutWrapper (layout);
			uint curIndex = 0, byteIndex = 0;
			if (Data.IsSomethingSelected) {
				ISegment selection = Data.MainSelection.Segment;
				HandleSelection (selection.Offset, selection.EndOffset, startOffset, endOffset, null, delegate(long start, long end) {
					Pango.AttrForeground selectedForeground = new Pango.AttrForeground (Style.Selection.Red, 
					                                                                    Style.Selection.Green, 
					                                                                    Style.Selection.Blue);
					selectedForeground.StartIndex = TranslateToUTF8Index (lineChars, TranslateColumn (start - startOffset), ref curIndex, ref byteIndex);
					selectedForeground.EndIndex = TranslateToUTF8Index (lineChars, TranslateColumn (end - startOffset) - 1, ref curIndex, ref byteIndex);
					result.Add (selectedForeground);
					
					Pango.AttrBackground attrBackground = new Pango.AttrBackground (Style.SelectionBg.Red, 
					                                                                Style.SelectionBg.Green, 
					                                                                Style.SelectionBg.Blue);
					attrBackground.StartIndex = selectedForeground.StartIndex;
					attrBackground.EndIndex = selectedForeground.EndIndex;
					result.Add (attrBackground);

				});
			}
			result.SetAttributes ();
			return result;
		}

		protected override LayoutWrapper RenderLine (long line)
		{
			var layout = new TextLayout (Editor);
			layout.Font = Editor.Options.Font;
//			layout.Tabs = tabArray;
			StringBuilder sb = new StringBuilder ();
			long startOffset = line * Editor.BytesInRow;
			long endOffset   = System.Math.Min (startOffset + Editor.BytesInRow, Data.Length);
			byte[] lineBytes = Data.GetBytes (startOffset, (int)(endOffset - startOffset));
			for (int i = 0; i < lineBytes.Length; i++) {
				sb.Append (string.Format ("{0:X2}", lineBytes[i]));
				if (i % Editor.Options.GroupBytes == 0)
					sb.Append (" "); // \t
			}
			
			layout.Text = sb.ToString ();
			Margin.LayoutWrapper result = new LayoutWrapper (layout);
			if (Data.IsSomethingSelected) {
				ISegment selection = Data.MainSelection.Segment;
				HandleSelection (selection.Offset, selection.EndOffset, startOffset, endOffset, null, delegate(long start, long end) {
					result.Layout.SetForeground (Style.Selection, (int)(start - startOffset) * 3, (int)(end - start) * 3 - 1);
					result.Layout.SetBackgound (Style.SelectionBg, (int)(start - startOffset) * 3, (int)(end - start) * 3 - 1);
				});
			}
			return result;
		}