Add Markup support to RichTextView

This includes a new MarkupView widget and a
new MarkupTextFormat to parse marked up
text to be displayed in a RichTextView.

Xwt.Gtk/Xwt.GtkBackend/RichTextViewBackend.cs

@@ -349,6 +349,11 @@ namespace Xwt.GtkBackend
 			{
 				//FIXME
 			}
+
+			public void EmitText (FormattedText markup)
+			{
+				EmitText (markup.Text, RichTextInlineStyle.Normal);
+			}
 		}
 	}
 }

Xwt.WPF/Xwt.WPFBackend/RichTextViewBackend.cs

@@ -259,6 +259,11 @@ namespace Xwt.WPFBackend
 				writer.WriteEndElement ();
 			}
 
+			public void EmitText (FormattedText text)
+			{
+				EmitText (text.Text, RichTextInlineStyle.Normal);
+			}
+
 			public void EmitStartParagraph (int indentLevel)
 			{
 				//FIXME: indentLevel

Xwt.XamMac/Xwt.Mac/RichTextViewBackend.cs

@@ -357,6 +357,11 @@ namespace Xwt.Mac
 				xmlWriter.WriteEndElement ();
 		}
 
+		public void EmitText (FormattedText text)
+		{
+			EmitText (text.Text, RichTextInlineStyle.Normal);
+		}
+
 		public void EmitStartHeader (int level)
 		{
 			if (level < 1)

Xwt/Xwt.Backends/IRichTextViewBackend.cs

@@ -34,6 +34,7 @@ namespace Xwt.Backends
 	{
 		// Emit text using specified style mask
 		void EmitText (string text, RichTextInlineStyle style);
+		void EmitText (FormattedText text);
 
 		// Emit a header (h1, h2, ...)
 		void EmitStartHeader (int level);

Xwt/Xwt.Formats/MarkupTextFormat.cs

@@ -0,0 +1,54 @@
+//
+// MarkupTextFormat.cs
+//
+// Author:
+//       Vsevolod Kukol <sevoku@microsoft.com>
+//
+// Copyright (c) 2016 Microsoft Corporation
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+using System;
+using System.IO;
+using Xwt.Backends;
+
+namespace Xwt.Formats
+{
+	public class MarkupTextFormat : TextFormat
+	{
+		public override void Parse (Stream input, IRichTextBuffer buffer)
+		{
+			using (var reader = new StreamReader (input))
+				ParseMarkup (reader.ReadToEnd (), buffer);
+		}
+
+		static void ParseMarkup (string markup, IRichTextBuffer buffer)
+		{
+			var paragraphs = markup.Replace ("\r\n", "\n").Split (new [] { "\n\n" }, StringSplitOptions.None);
+			foreach (var p in paragraphs) {
+				buffer.EmitStartParagraph (0);
+				var formatted = FormattedText.FromMarkup (p);
+				if (formatted.Attributes.Count > 0)
+					buffer.EmitText (formatted);
+				else
+					buffer.EmitText (p, RichTextInlineStyle.Normal);
+				buffer.EmitEndParagraph ();
+			}
+		}
+	}
+}

Xwt/Xwt.Formats/TextFormat.cs

@@ -35,6 +35,7 @@ namespace Xwt.Formats
 	{
 		public static readonly TextFormat Markdown = new MarkdownTextFormat ();
 		public static readonly TextFormat Plain = new PlainTextFormat ();
+		public static readonly TextFormat Markup = new MarkupTextFormat ();
 
 		// Parses the given input stream into the given buffer
 		public abstract void Parse (Stream input, IRichTextBuffer buffer);

Xwt/Xwt.csproj

@@ -264,6 +264,7 @@
     <Compile Include="Xwt.Drawing\DrawingImage.cs" />
     <Compile Include="Xwt.Drawing\BitmapImage.cs" />
     <Compile Include="Xwt.Formats\PlainTextFormat.cs" />
+    <Compile Include="Xwt.Formats\MarkupTextFormat.cs" />
     <Compile Include="Xwt.Drawing\ImageFileType.cs" />
     <Compile Include="Xwt\Slider.cs" />
     <Compile Include="Xwt.Backends\ISliderBackend.cs" />

Xwt/Xwt/RichTextView.cs

@@ -146,5 +146,24 @@ namespace Xwt
 			Markdown = string.Empty;
 		}
 	}
+
+	public class MarkupView : RichTextView
+	{
+		string markup;
+		public string Markup {
+			get {
+				return markup;
+			}
+			set {
+				markup = value;
+				LoadText (value, TextFormat.Markup);
+			}
+		}
+
+		public MarkupView ()
+		{
+			Markup = string.Empty;
+		}
+	}
 }