/// <summary>
/// Perform a simple lexical styling of the given range of content. This will *not*
/// correctly style many constructs, and it's not smart enough to understand
/// context. But it's fast enough that it can style most content while you type, and
/// it's accurate enough that it's good enough for a first pass. Various background
/// threads will be responsible for running the full parser and re-styling the content
/// more accurately afterward.
/// </summary>
/// <param name="editor">The editor that holds the content.</param>
/// <param name="startPos">The starting character position within the text to style.</param>
/// <param name="endPos">The ending character position within the text to style.</param>
/// <param name="filename">The name of the file being styled (for generating errors)</param>
public static void StyleRange(Scintilla editor, TextEditorControl owner, int startPos, int endPos, string filename)
{
try
{
// Ensure startPos/endPos actually refer to the document.
ValidateStartAndEndPos(editor, ref startPos, ref endPos);
// Get the real range of lines to style.
int startLine = editor.LineFromPosition(startPos);
int endLine = editor.LineFromPosition(endPos);
// Remove all the error/warning marks in this range.
owner.ClearLineMarks(startLine + 1, endLine - startLine + 1);
// Now find the actual document start and end of the range we're going to color.
int trueStartPos = editor.Lines[startLine].Position;
int trueEndPos = editor.Lines[endLine].EndPosition;
// Get the text itself in that range.
string textSlice = editor.GetTextRange(trueStartPos, trueEndPos - trueStartPos);
// Ask the real Smile Lexer to begin lexical analysis on it.
SmileLibInterop.Lexer lexer = new SmileLibInterop.Lexer(textSlice,
0, textSlice.Length, filename, startLine + 1, 1, true);
editor.StartStyling(trueStartPos);
Token token;
int lastPos = 0;
Token previousToken = null;
while ((token = lexer.Next()).Kind != TokenKind.EOI)
{
LexerPosition lexerPosition = token.Position;
int tokenStartPos = lexerPosition.LineStart + lexerPosition.Column - 1;
int tokenLength = lexerPosition.Length;
if (tokenStartPos > lastPos)
{
// Token somehow skipped over some content, so style it plain.
editor.SetStyling(tokenStartPos - lastPos, (int)StyleKind.Default);
editor.IndicatorClearRange(trueStartPos + lastPos, tokenStartPos - lastPos);
System.Diagnostics.Debug.WriteLine($"Warning: Lexer skipped {tokenStartPos - lastPos} characters at {lastPos}.");
}
else if (tokenStartPos < lastPos)
{
// For some reason, the previous token had too many characters in it,
// so shorten this one by a bit to make up for that mistake.
tokenLength -= lastPos - tokenStartPos;
System.Diagnostics.Debug.WriteLine($"Warning: Lexer grabbed too many characters ({lastPos - tokenStartPos} extra) at {lastPos}.");
}
if (tokenLength > 0)
{
StyleKind styleKind = GetDefaultStyleKindForToken(previousToken, token);
editor.SetStyling(tokenLength, (int)styleKind);
if (styleKind == StyleKind.Meta_Error)
{
editor.IndicatorCurrent = (int)IndicatorKind.Error;
editor.IndicatorFillRange(trueStartPos + tokenStartPos, tokenLength);
owner.SetLineMark(lexerPosition.Line, IndicatorKind.Error);
}
else
{
editor.IndicatorClearRange(trueStartPos + tokenStartPos, tokenLength);
}
}
lastPos = tokenStartPos + tokenLength;
previousToken = IsSemanticToken(token) ? token : previousToken;
}
}
catch (Exception e)
{
// Should never get here, but just in case, we swallow errors
// and hope a later pass will restyle the content better.
System.Diagnostics.Debug.WriteLine("Warning: LexicalStyler.StyleRange() crashed: " + e.Message);
}
}
public void Restyle()
{
// Get the current text from the editor.
string text = null;
string filename = null;
RunOnWinFormsThread(() =>
{
if (ShouldCancel)
{
return;
}
filename = _owner.Filename;
text = _editor.Text;
});
if (ShouldCancel)
{
return;
}
// First, do a fast easy pass over the input to find its maximum width,
// so that we can keep the horizontal scrollbar up-to-date.
MaximumInfo maximumInfo = CalculateMaximumInfo(text, _configurator.TextEditorConfig.Indentation);
RunOnWinFormsThread(() =>
{
if (ShouldCancel)
{
return;
}
_owner.SetMaximumInfo(maximumInfo);
_owner.ClearLineMarks();
});
// Create a Smile Lexer to begin lexical analysis on it.
SmileLibInterop.Lexer lexer = new SmileLibInterop.Lexer(text, 0, text.Length, filename, 1, 1, true);
// Spin over the input, collect tokens in approximately ~64K chunks (or ~1024 tokens),
// and pass them to the LexicalStyler class to style.
int currentChunkSize = 0;
const int MaximumChunkSize = 64 * 1024;
const int TokenWeight = 8 * 8; // Approximate guess for how much memory a Token object uses.
List <Token> tokens = new List <Token>();
Token token;
while ((token = lexer.Next()).Kind != TokenKind.EOI)
{
tokens.Add(token);
currentChunkSize += token.Position.Length + TokenWeight;
if (currentChunkSize >= MaximumChunkSize)
{
if (ShouldCancel)
{
break;
}
RunOnWinFormsThread(() =>
{
if (ShouldCancel)
{
return;
}
LexicalStyler.StyleTokens(_editor, _owner, tokens);
});
tokens.Clear();
currentChunkSize = 0;
if (ShouldCancel)
{
break;
}
}
}
if (tokens.Any())
{
RunOnWinFormsThread(() =>
{
if (ShouldCancel)
{
return;
}
LexicalStyler.StyleTokens(_editor, _owner, tokens);
});
}
}
