Syntax highlighting HTML markup using DevExpress CodeParser library and Syntax Highlight tokens

C#
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using DevExpress.XtraRichEdit;
using DevExpress.XtraRichEdit.Services;

namespace WindowsFormsApplication1 {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e) {            
            richEditControl1.ReplaceService<ISyntaxHighlightService>(new HTMLSyntaxHighlightService(richEditControl1));
            using(IRichEditDocumentServer server = richEditControl1.CreateDocumentServer()) {
                server.Text = "some HTML text";
                richEditControl1.Text = server.HtmlText;
            }
            richEditControl1.Document.DefaultCharacterProperties.FontName = "Consolas";
            richEditControl1.Document.DefaultCharacterProperties.FontSize = 9;
        }
    }
}

Visual Basic
Imports System
Imports System.ComponentModel
Imports System.Drawing
Imports System.Windows.Forms
Imports DevExpress.XtraRichEdit
Imports DevExpress.XtraRichEdit.Services

Namespace WindowsFormsApplication1

    Public Partial Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
            richEditControl1.ReplaceService(Of ISyntaxHighlightService)(New HTMLSyntaxHighlightService(richEditControl1))
            Using server As IRichEditDocumentServer = richEditControl1.CreateDocumentServer()
                server.Text = "some HTML text"
                richEditControl1.Text = server.HtmlText
            End Using

            richEditControl1.Document.DefaultCharacterProperties.FontName = "Consolas"
            richEditControl1.Document.DefaultCharacterProperties.FontSize = 9
        End Sub
    End Class
End Namespace

C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DevExpress.XtraRichEdit.Services;
using DevExpress.XtraRichEdit.API.Native;
using DevExpress.CodeParser;
using System.Drawing;
using DevExpress.XtraRichEdit;

namespace WindowsFormsApplication1 {
    public class HTMLSyntaxHighlightService : ISyntaxHighlightService {
        readonly RichEditControl syntaxEditor;

        Dictionary<TokenCategory, SyntaxHighlightProperties> TokensMapping = new Dictionary<TokenCategory, SyntaxHighlightProperties>(); 

        SyntaxHighlightProperties textProperties;

        void AddTokensMapping(TokenCategory category, Color foreColor) {
            SyntaxHighlightProperties tokenProperties = new SyntaxHighlightProperties();
            tokenProperties.ForeColor = foreColor;
            TokensMapping.Add(category, tokenProperties);
        }

        SyntaxHighlightProperties GetTokensMapping(TokenCategory category) {
            if(TokensMapping.ContainsKey(category)) return TokensMapping[category];
            else return textProperties;        
        }

        public HTMLSyntaxHighlightService(RichEditControl syntaxEditor) {
            this.syntaxEditor = syntaxEditor;
        }

        void HighlightSyntax(TokenCollection tokens) {
            if(TokensMapping.Count == 0) {
                AddTokensMapping(TokenCategory.HtmlAttributeName, Color.Red);
                AddTokensMapping(TokenCategory.HtmlAttributeValue, Color.Blue);
                AddTokensMapping(TokenCategory.HtmlComment, Color.Green);
                AddTokensMapping(TokenCategory.HtmlElementName, Color.Brown);
                AddTokensMapping(TokenCategory.HtmlEntity, Color.Green);
                AddTokensMapping(TokenCategory.HtmlOperator, Color.Blue);
                AddTokensMapping(TokenCategory.HtmlServerSideScript, Color.Gray);
                AddTokensMapping(TokenCategory.HtmlString, Color.Black);
                AddTokensMapping(TokenCategory.HtmlTagDelimiter, Color.Blue);
                AddTokensMapping(TokenCategory.CssComment, Color.Green);
                AddTokensMapping(TokenCategory.CssKeyword, Color.Red);
                AddTokensMapping(TokenCategory.CssPropertyName, Color.Red);
                AddTokensMapping(TokenCategory.CssPropertyValue, Color.Blue);
                AddTokensMapping(TokenCategory.CssSelector, Color.Brown);
                AddTokensMapping(TokenCategory.CssStringValue, Color.Blue);

                textProperties = new SyntaxHighlightProperties();
                textProperties.ForeColor = Color.Black;                
            }

            if(tokens == null || tokens.Count == 0)
                return;

            Document document = syntaxEditor.Document;
            List<SyntaxHighlightToken> syntaxTokens = new List<SyntaxHighlightToken>(tokens.Count);
            foreach(Token token in tokens) {
                HighlightCategorizedToken((CategorizedToken)token, syntaxTokens);
            }
            document.ApplySyntaxHighlight(syntaxTokens);
        }

        void HighlightCategorizedToken(CategorizedToken token, List<SyntaxHighlightToken> syntaxTokens) {
            Color backColor = syntaxEditor.ActiveView.BackColor;
            TokenCategory category = token.Category;
            syntaxTokens.Add(SetTokenColor(token, GetTokensMapping(category), backColor));

        }
        SyntaxHighlightToken SetTokenColor(Token token, SyntaxHighlightProperties foreColor, Color backColor) {
            if(syntaxEditor.Document.Paragraphs.Count < token.Range.Start.Line)
                return null;
            int paragraphStart = DocumentHelper.GetParagraphStart(syntaxEditor.Document.Paragraphs[token.Range.Start.Line - 1]);
            int tokenStart = paragraphStart + token.Range.Start.Offset - 1;
            if(token.Range.End.Line != token.Range.Start.Line)
                paragraphStart = DocumentHelper.GetParagraphStart(syntaxEditor.Document.Paragraphs[token.Range.End.Line - 1]);

            int tokenEnd = paragraphStart + token.Range.End.Offset - 1;
            
            return new SyntaxHighlightToken(tokenStart, tokenEnd - tokenStart, foreColor);
        }

        #region #ISyntaxHighlightServiceMembers
        public void Execute() {
            string newText = syntaxEditor.Text;
            // Use DevExpress.CodeParser to parse text into tokens.
            ITokenCategoryHelper tokenHelper = TokenCategoryHelperFactory.CreateHelper(ParserLanguageID.Html);
            TokenCollection highlightTokens;
            highlightTokens = tokenHelper.GetTokens(newText);
            HighlightSyntax(highlightTokens);
        }

        public void ForceExecute() {
            Execute();
        }
        #endregion #ISyntaxHighlightServiceMembers
    }
}

Visual Basic
Imports System.Collections.Generic
Imports DevExpress.XtraRichEdit.Services
Imports DevExpress.XtraRichEdit.API.Native
Imports DevExpress.CodeParser
Imports System.Drawing
Imports DevExpress.XtraRichEdit

Namespace WindowsFormsApplication1

    Public Class HTMLSyntaxHighlightService
        Implements ISyntaxHighlightService

        Private ReadOnly syntaxEditor As RichEditControl

        Private TokensMapping As Dictionary(Of TokenCategory, SyntaxHighlightProperties) = New Dictionary(Of TokenCategory, SyntaxHighlightProperties)()

        Private textProperties As SyntaxHighlightProperties

        Private Sub AddTokensMapping(ByVal category As TokenCategory, ByVal foreColor As Color)
            Dim tokenProperties As SyntaxHighlightProperties = New SyntaxHighlightProperties()
            tokenProperties.ForeColor = foreColor
            TokensMapping.Add(category, tokenProperties)
        End Sub

        Private Function GetTokensMapping(ByVal category As TokenCategory) As SyntaxHighlightProperties
            If TokensMapping.ContainsKey(category) Then
                Return TokensMapping(category)
            Else
                Return textProperties
            End If
        End Function

        Public Sub New(ByVal syntaxEditor As RichEditControl)
            Me.syntaxEditor = syntaxEditor
        End Sub

        Private Sub HighlightSyntax(ByVal tokens As TokenCollection)
            If TokensMapping.Count = 0 Then
                AddTokensMapping(TokenCategory.HtmlAttributeName, Color.Red)
                AddTokensMapping(TokenCategory.HtmlAttributeValue, Color.Blue)
                AddTokensMapping(TokenCategory.HtmlComment, Color.Green)
                AddTokensMapping(TokenCategory.HtmlElementName, Color.Brown)
                AddTokensMapping(TokenCategory.HtmlEntity, Color.Green)
                AddTokensMapping(TokenCategory.HtmlOperator, Color.Blue)
                AddTokensMapping(TokenCategory.HtmlServerSideScript, Color.Gray)
                AddTokensMapping(TokenCategory.HtmlString, Color.Black)
                AddTokensMapping(TokenCategory.HtmlTagDelimiter, Color.Blue)
                AddTokensMapping(TokenCategory.CssComment, Color.Green)
                AddTokensMapping(TokenCategory.CssKeyword, Color.Red)
                AddTokensMapping(TokenCategory.CssPropertyName, Color.Red)
                AddTokensMapping(TokenCategory.CssPropertyValue, Color.Blue)
                AddTokensMapping(TokenCategory.CssSelector, Color.Brown)
                AddTokensMapping(TokenCategory.CssStringValue, Color.Blue)
                textProperties = New SyntaxHighlightProperties()
                textProperties.ForeColor = Color.Black
            End If

            If tokens Is Nothing OrElse tokens.Count = 0 Then Return
            Dim document As Document = syntaxEditor.Document
            Dim syntaxTokens As List(Of SyntaxHighlightToken) = New List(Of SyntaxHighlightToken)(tokens.Count)
            For Each token As Token In tokens
                HighlightCategorizedToken(CType(token, CategorizedToken), syntaxTokens)
            Next

            document.ApplySyntaxHighlight(syntaxTokens)
        End Sub

        Private Sub HighlightCategorizedToken(ByVal token As CategorizedToken, ByVal syntaxTokens As List(Of SyntaxHighlightToken))
            Dim backColor As Color = syntaxEditor.ActiveView.BackColor
            Dim category As TokenCategory = token.Category
            syntaxTokens.Add(SetTokenColor(token, GetTokensMapping(category), backColor))
        End Sub

        Private Function SetTokenColor(ByVal token As Token, ByVal foreColor As SyntaxHighlightProperties, ByVal backColor As Color) As SyntaxHighlightToken
            If syntaxEditor.Document.Paragraphs.Count < token.Range.Start.Line Then Return Nothing
            Dim paragraphStart As Integer = DocumentHelper.GetParagraphStart(syntaxEditor.Document.Paragraphs(token.Range.Start.Line - 1))
            Dim tokenStart As Integer = paragraphStart + token.Range.Start.Offset - 1
            If token.Range.End.Line <> token.Range.Start.Line Then paragraphStart = DocumentHelper.GetParagraphStart(syntaxEditor.Document.Paragraphs(token.Range.End.Line - 1))
            Dim tokenEnd As Integer = paragraphStart + token.Range.End.Offset - 1
            Return New SyntaxHighlightToken(tokenStart, tokenEnd - tokenStart, foreColor)
        End Function

'#Region "#ISyntaxHighlightServiceMembers"
        Public Sub Execute() Implements ISyntaxHighlightService.Execute
            Dim newText As String = syntaxEditor.Text
            ' Use DevExpress.CodeParser to parse text into tokens.
            Dim tokenHelper As ITokenCategoryHelper = TokenCategoryHelperFactory.CreateHelper(ParserLanguageID.Html)
            Dim highlightTokens As TokenCollection
            highlightTokens = tokenHelper.GetTokens(newText)
            HighlightSyntax(highlightTokens)
        End Sub

        Public Sub ForceExecute() Implements ISyntaxHighlightService.ForceExecute
            Execute()
        End Sub
'#End Region  ' #ISyntaxHighlightServiceMembers
    End Class
End Namespace