!include once #1015780 // RSyntaxTextArea libs / imports [include]
 
import org.fife.ui.rsyntaxtextarea.RSyntaxDocument;

sclass RSTADummyParser extends org.fife.ui.rsyntaxtextarea.parser.AbstractParser {
  delegate ParseResult, DefaultParseResult, DefaultParserNotice
    to org.fife.ui.rsyntaxtextarea.parser.
    
  // list of errors to show. also used to verify that we're on the
  // correct text version
  gettable L<Error> errors;
  
  sclass Error {
    settable TokenRangeWithSrc tokenRange;
    settable S msg;
  }

  @Override
  public ParseResult parse(RSyntaxDocument doc, String style) ctex {
    var result = new DefaultParseResult(this);
    var errors = this.errors;
    if (empty(errors)) ret result;
    
    // if wrong text, temporarily return no errors
    // (forceReparse will be called by actual parser)
    S text = doc.getText(0, doc.getLength());
    if (!eq(text, first(errors).tokenRange.fullSourceText()))
      ret result;
    
    // We're on the right text, convert messages and return them  
    for (Error e : errors) {
      LineAndColumn start = e.tokenRange.startLineAndCol();
      LineAndColumn end = e.tokenRange.endLineAndCol();
      int length = end.line > start.line
        // spanning multiple lines
        ? lengthOfLine(text, start.line-1)-(start.col-1)
        // start and end in same line
        : end.col-start.col;
      result.addNotice(new DefaultParserNotice(this,
        e.msg, start.line-1, start.col-1, length));
    }
    
    ret result;
  }
  
  void setErrors(L<Error> errors, RSyntaxTextArea textArea) {
    this.errors = errors;
    swing {
      textArea.forceReparsing(RSTADummyParser.this);
    }
  }
  
  void install(RSyntaxTextArea textArea) swing {
    textArea.addParser(RSTADummyParser.this);
  }
}

Began life as a copy of #1035120