/// <summary>
/// Highlights elements in the specified text.
///
/// The highlighter tries to find matches of the patterns specified by the Patterns property in the provided text.
/// For each match a IHighlighterToken instance is returned and the color is used as defined in the matched pattern
/// definition. Except for multi line comments an keywords/identifiers the Patterns list also defines a token type
/// precedence, i.e. a highlighter token instance is always returned for the first token type matched by the regex,
/// even if mutliple token types are matched simultanously.
/// </summary>
/// <param name="text">Text, which should be highlighted.</param>
/// <param name="activeBlock">Active multi line block.</param>
/// <returns>Enumeration of IHighlighterToken instances.</returns>
public IEnumerable <Interfaces.IHighlighterToken> Highlight(string text, IHighlighterToken activeBlock = null)
{
if (text != null)
{
bool activeBlockIsComment = activeBlock != null && activeBlock.Type.Equals("COMMENT", StringComparison.OrdinalIgnoreCase);
bool insideComment = activeBlock != null && activeBlock.Type.Equals("COMMENT", StringComparison.OrdinalIgnoreCase);
int commentStart = insideComment ? 0 : -1;
int commentEnd = -1;
uint commentColor = insideComment ? activeBlock.Color : 0;
var matches = mPatternRegEx.Matches(text);
// Perform regex matching
foreach (System.Text.RegularExpressions.Match match in matches)
{
// Find first group, containing a match
for (int i = 1; i <= match.Groups.Count; ++i)
{
var currentGroup = match.Groups[i];
if (currentGroup.Success)
{
string tokenType = mPatternRegEx.GroupNameFromNumber(i);
// Not in multi-line comment?
if (!(insideComment))
{
// Special treatment for identifiers and keywords...
if (tokenType.Equals("IDENTIFIER", StringComparison.OrdinalIgnoreCase) && mKeywordRegEx != null)
{
string identifier = currentGroup.Value;
var keywordMatch = mKeywordRegEx.Match(identifier);
// Keywords have precedence over identifiers, but identifiers have precendence over keywords,
// if the keyword is only contained in the identifier.
if (keywordMatch.Success && keywordMatch.Length == identifier.Length)
{
// Determine keyword token type
for (int g = 1; g <= keywordMatch.Groups.Count; ++g)
{
var currentKeywordGroup = keywordMatch.Groups[g];
if (currentKeywordGroup.Success)
{
tokenType = mKeywordRegEx.GroupNameFromNumber(g);
break;
}
}
yield return(new Interfaces.HighlighterToken(mTokenTypeToPattern[tokenType].FirstOrDefault().Color, tokenType, currentGroup.Index, currentGroup.Index + currentGroup.Length));
}
}
// Multiline comment handling...
if (tokenType.Equals("COMMENT_START", StringComparison.OrdinalIgnoreCase) || tokenType.Equals("CommentStart", StringComparison.OrdinalIgnoreCase))
{
insideComment = true;
commentStart = currentGroup.Index;
commentColor = mTokenTypeToPattern[tokenType].FirstOrDefault().Color;
}
else
// Single line comment handling...
if (tokenType.Equals("LINE_COMMENT", StringComparison.OrdinalIgnoreCase) || tokenType.Equals("LineComment", StringComparison.OrdinalIgnoreCase))
{
commentColor = mTokenTypeToPattern[tokenType].FirstOrDefault().Color;
var tagColor = mTokenTypeToPattern["TAG"].FirstOrDefault().Color;
// Handle tags...
if (mTagRegEx != null)
{
commentStart = currentGroup.Index;
string lineComment = currentGroup.Value;
var tags = mTagRegEx.Matches(lineComment);
if (tags.Count > 0)
{
foreach (System.Text.RegularExpressions.Match tag in tags)
{
commentEnd = tag.Index + currentGroup.Index;
int tagStart = tag.Index + currentGroup.Index;
int tagEnd = tagStart + tag.Length;
if (commentEnd > commentStart)
{
yield return(new Interfaces.HighlighterToken(commentColor, tokenType, commentStart, commentEnd));
}
if (tagEnd > tagStart)
{
yield return(new Interfaces.HighlighterToken(tagColor, "TAG", tagStart, tagEnd));
}
commentStart = tagEnd;
}
commentEnd = currentGroup.Index + currentGroup.Length;
if (commentEnd > commentStart)
{
yield return(new Interfaces.HighlighterToken(commentColor, tokenType, commentStart, commentEnd));
}
}
else
{
yield return(new Interfaces.HighlighterToken(mTokenTypeToPattern[tokenType].FirstOrDefault().Color, tokenType, currentGroup.Index, currentGroup.Index + currentGroup.Length));
}
}
else
{
yield return(new Interfaces.HighlighterToken(mTokenTypeToPattern[tokenType].FirstOrDefault().Color, tokenType, currentGroup.Index, currentGroup.Index + currentGroup.Length));
}
}
else
// Normal match...
{
yield return(new Interfaces.HighlighterToken(mTokenTypeToPattern[tokenType].FirstOrDefault().Color, tokenType, currentGroup.Index, currentGroup.Index + currentGroup.Length));
}
}
else
{
// Handle tag
if (tokenType.Equals("TAG", StringComparison.OrdinalIgnoreCase))
{
commentEnd = currentGroup.Index;
yield return(new Interfaces.HighlighterToken(commentColor, "COMMENT", commentStart, commentEnd));
yield return(new Interfaces.HighlighterToken(mTokenTypeToPattern[tokenType].FirstOrDefault().Color, tokenType, currentGroup.Index, currentGroup.Index + currentGroup.Length));
commentStart = currentGroup.Index + currentGroup.Length;
insideComment = true;
}
// Multiline comment handling...
if (tokenType.Equals("COMMENT_END", StringComparison.OrdinalIgnoreCase) || tokenType.Equals("CommentEnd", StringComparison.OrdinalIgnoreCase))
{
insideComment = false;
commentEnd = currentGroup.Index + currentGroup.Length;
yield return(new Interfaces.HighlighterToken(commentColor, "COMMENT", commentStart, commentEnd));
}
}
break;
}
}
}
// Emit comment token if not closed
if (insideComment && commentStart >= 0)
{
yield return(new Interfaces.HighlighterToken(commentColor, "COMMENT", commentStart, text.Length));
}
}
else
{
yield break;
}
}
/// <summary>
/// Highlights elements in the text to which access is provided through the text reader.
/// </summary>
/// <param name="inputReader">Text reader, providing access to the text, which should be highlighted.</param>
/// <param name="activeBlock">Active multi line block.</param>
/// <returns>Enumeration of IHighlighterToken instances.</returns>
public IEnumerable <Interfaces.IHighlighterToken> Highlight(System.IO.TextReader inputReader, IHighlighterToken activeBlock = null)
{
if (inputReader != null)
{
string text = inputReader.ReadToEnd();
return(Highlight(text, activeBlock));
}
else
{
return(new Interfaces.HighlighterToken[] { });
}
}
