highlighter.cpp Example File
richtext/syntaxhighlighter/highlighter.cpp
/****************************************************************************
**
** Copyright (C) 2005-2005 Trolltech AS. All rights reserved.
**
** This file is part of the documentation of the Qt Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
** information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/
#include <QtGui>
#include "highlighter.h"
Highlighter::Highlighter(QObject *parent)
: QObject(parent)
{
}
void Highlighter::addToDocument(QTextDocument *doc)
{
connect(doc, SIGNAL(contentsChange(int, int, int)),
this, SLOT(highlight(int, int, int)));
}
void Highlighter::addMapping(const QString &pattern,
const QTextCharFormat &format)
{
mappings[pattern] = format;
}
void Highlighter::highlight(int position, int removed, int added)
{
QTextDocument *doc = qobject_cast<QTextDocument *>(sender());
QTextBlock block = doc->findBlock(position);
if (!block.isValid())
return;
QTextBlock endBlock;
if (added > removed)
endBlock = doc->findBlock(position + added);
else
endBlock = block;
while (block.isValid() && !(endBlock < block)) {
highlightBlock(block);
block = block.next();
}
}
void Highlighter::highlightBlock(QTextBlock block)
{
QTextLayout *layout = block.layout();
const QString text = block.text();
QList<QTextLayout::FormatRange> overrides;
foreach (QString pattern, mappings.keys()) {
QRegExp expression(pattern);
int i = text.indexOf(expression);
while (i >= 0) {
QTextLayout::FormatRange range;
range.start = i;
range.length = expression.matchedLength();
range.format = mappings[pattern];
overrides << range;
i = text.indexOf(expression, i + expression.matchedLength());
}
}
layout->setAdditionalFormats(overrides);
const_cast<QTextDocument *>(block.document())->markContentsDirty(
block.position(), block.length());
}