qgsexpressionhighlighter.cpp

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/***************************************************************************
    qgsexpressionhighlighter.cpp - A syntax highlighter for a qgsexpression
     --------------------------------------
    Date                 :  28-Dec-2011
    Copyright            : (C) 2011 by Nathan Woodrow
    Email                : woodrow.nathan at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgsexpressionhighlighter.h"
 
#include <QString>
 
#include "moc_qgsexpressionhighlighter.cpp"
 
using namespace Qt::StringLiterals;
 
QgsExpressionHighlighter::QgsExpressionHighlighter( QTextDocument *parent )
  : QSyntaxHighlighter( parent )
{
  HighlightingRule rule;
 
  keywordFormat.setForeground( Qt::darkBlue );
  keywordFormat.setFontWeight( QFont::Bold );
  QStringList keywordPatterns;
  keywordPatterns << u"\\bCASE\\b"_s << u"\\bWHEN\\b"_s << u"\\bTHEN\\b"_s
                  << u"\\bELSE\\b"_s << u"\\bEND\\b"_s;
 
  const auto constKeywordPatterns = keywordPatterns;
  for ( const QString &pattern : constKeywordPatterns )
  {
    rule.pattern = QRegularExpression( pattern, QRegularExpression::CaseInsensitiveOption );
    rule.format = keywordFormat;
    highlightingRules.append( rule );
  }
 
  quotationFormat.setForeground( Qt::darkGreen );
  rule.pattern = QRegularExpression( "\'[^\'\r\n]*\'" );
  rule.format = quotationFormat;
  highlightingRules.append( rule );
 
  columnNameFormat.setForeground( Qt::darkRed );
  rule.pattern = QRegularExpression( "\"[^\"\r\n]*\"" );
  rule.format = columnNameFormat;
  highlightingRules.append( rule );
}
 
void QgsExpressionHighlighter::addFields( const QStringList &fieldList )
{
  columnNameFormat.setForeground( Qt::darkRed );
  HighlightingRule rule;
  const auto constFieldList = fieldList;
  for ( const QString &field : constFieldList )
  {
    if ( field.isEmpty() ) // this really happened :)
      continue;
    rule.pattern = QRegularExpression( "\\b" + field + "\\b" );
    rule.format = columnNameFormat;
    highlightingRules.append( rule );
  }
}
 
void QgsExpressionHighlighter::highlightBlock( const QString &text )
{
  const auto constHighlightingRules = highlightingRules;
  for ( const HighlightingRule &rule : constHighlightingRules )
  {
    const QRegularExpression expression( rule.pattern );
    QRegularExpressionMatch match = expression.match( text );
    while ( match.hasMatch() )
    {
      const int index = match.capturedStart();
      const int length = match.capturedLength();
      if ( length == 0 )
        break; // avoid infinite loops
      setFormat( index, length, rule.format );
      match = expression.match( text, index + length );
    }
  }
}