|  | Home · All Classes · All Functions · Overviews

# highlighter.cpp Example File
richtext/syntaxhighlighter/highlighter.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
     ** Commercial Usage
     ** Licensees holding valid Qt Commercial licenses may use this file in
     ** accordance with the Qt Commercial License Agreement provided with the
     ** Software or, alternatively, in accordance with the terms contained in
     ** a written agreement between you and Nokia.
     **
     ** GNU Lesser General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU Lesser
     ** General Public License version 2.1 as published by the Free Software
     ** Foundation and appearing in the file LICENSE.LGPL included in the
     ** packaging of this file.  Please review the following information to
     ** ensure the GNU Lesser General Public License version 2.1 requirements
     ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
     **
     ** In addition, as a special exception, Nokia gives you certain additional
     ** rights.  These rights are described in the Nokia Qt LGPL Exception
     ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
     **
     ** GNU General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU
     ** General Public License version 3.0 as published by the Free Software
     ** Foundation and appearing in the file LICENSE.GPL included in the
     ** packaging of this file.  Please review the following information to
     ** ensure the GNU General Public License version 3.0 requirements will be
     ** met: http://www.gnu.org/copyleft/gpl.html.
     **
     ** If you have questions regarding the use of this file, please contact
     ** Nokia at qt-info@nokia.com.
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include <QtGui>

     #include "highlighter.h"

     Highlighter::Highlighter(QTextDocument *parent)
         : QSyntaxHighlighter(parent)
     {
         HighlightingRule rule;

         keywordFormat.setForeground(Qt::darkBlue);
         keywordFormat.setFontWeight(QFont::Bold);
         QStringList keywordPatterns;
         keywordPatterns << "\\bchar\\b" << "\\bclass\\b" << "\\bconst\\b"
                         << "\\bdouble\\b" << "\\benum\\b" << "\\bexplicit\\b"
                         << "\\bfriend\\b" << "\\binline\\b" << "\\bint\\b"
                         << "\\blong\\b" << "\\bnamespace\\b" << "\\boperator\\b"
                         << "\\bprivate\\b" << "\\bprotected\\b" << "\\bpublic\\b"
                         << "\\bshort\\b" << "\\bsignals\\b" << "\\bsigned\\b"
                         << "\\bslots\\b" << "\\bstatic\\b" << "\\bstruct\\b"
                         << "\\btemplate\\b" << "\\btypedef\\b" << "\\btypename\\b"
                         << "\\bunion\\b" << "\\bunsigned\\b" << "\\bvirtual\\b"
                         << "\\bvoid\\b" << "\\bvolatile\\b";
         foreach (const QString &pattern, keywordPatterns) {
             rule.pattern = QRegExp(pattern);
             rule.format = keywordFormat;
             highlightingRules.append(rule);
         }

         classFormat.setFontWeight(QFont::Bold);
         classFormat.setForeground(Qt::darkMagenta);
         rule.pattern = QRegExp("\\bQ[A-Za-z]+\\b");
         rule.format = classFormat;
         highlightingRules.append(rule);

         singleLineCommentFormat.setForeground(Qt::red);
         rule.pattern = QRegExp("//[^\n]*");
         rule.format = singleLineCommentFormat;
         highlightingRules.append(rule);

         multiLineCommentFormat.setForeground(Qt::red);

         quotationFormat.setForeground(Qt::darkGreen);
         rule.pattern = QRegExp("\".*\"");
         rule.format = quotationFormat;
         highlightingRules.append(rule);

         functionFormat.setFontItalic(true);
         functionFormat.setForeground(Qt::blue);
         rule.pattern = QRegExp("\\b[A-Za-z0-9_]+(?=\\()");
         rule.format = functionFormat;
         highlightingRules.append(rule);

         commentStartExpression = QRegExp("/\\*");
         commentEndExpression = QRegExp("\\*/");
     }

     void Highlighter::highlightBlock(const QString &text)
     {
         foreach (const HighlightingRule &rule, highlightingRules) {
             QRegExp expression(rule.pattern);
             int index = expression.indexIn(text);
             while (index >= 0) {
                 int length = expression.matchedLength();
                 setFormat(index, length, rule.format);
                 index = expression.indexIn(text, index + length);
             }
         }
         setCurrentBlockState(0);

         int startIndex = 0;
         if (previousBlockState() != 1)
             startIndex = commentStartExpression.indexIn(text);

         while (startIndex >= 0) {
             int endIndex = commentEndExpression.indexIn(text, startIndex);
             int commentLength;
             if (endIndex == -1) {
                 setCurrentBlockState(1);
                 commentLength = text.length() - startIndex;
             } else {
                 commentLength = endIndex - startIndex
                                 + commentEndExpression.matchedLength();
             }
             setFormat(startIndex, commentLength, multiLineCommentFormat);
             startIndex = commentStartExpression.indexIn(text, startIndex + commentLength);
         }
     }