qtextimagehandler.cpp

奇趣公司比较新的qt/emd版本

/****************************************************************************
**
** Copyright (C) 1992-2007 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 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 GNU
** General Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at [e-mail].
**
** In addition, as a special exception, Trolltech gives you certain
** additional rights. These rights are described in the Trolltech GPL
** Exception version 1.0, which can be found at
** http://www.trolltech.com/products/qt/gplexception/ and in the file
** GPL_EXCEPTION.txt in this package.
**
** In addition, as a special exception, Trolltech, as the sole copyright
** holder for Qt Designer, grants users of the Qt/Eclipse Integration
** plug-in the right for the Qt/Eclipse Integration to link to
** functionality provided by Qt Designer and its related libraries.
**
** Trolltech reserves all rights not expressly granted herein.
**
** 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 "qtextimagehandler_p.h"

#include <qtextformat.h>
#include <qpainter.h>
#include <qpixmapcache.h>
#include <qdebug.h>
#include <private/qtextengine_p.h>
#include <qpalette.h>
#include <qtextbrowser.h>

// set by the mime source factory in Qt3Compat
QTextImageHandler::ExternalImageLoaderFunction QTextImageHandler::externalLoader = 0;

static QPixmap getPixmap(QTextDocument *doc, const QTextImageFormat &format)
{
    QPixmap pm;

    QString name = format.name();
    if (name.startsWith(QLatin1String(":/"))) // auto-detect resources
        name.prepend(QLatin1String("qrc"));
    QUrl url(name);
    const QVariant data = doc->resource(QTextDocument::ImageResource, url);
    if (data.type() == QVariant::Pixmap || data.type() == QVariant::Image) {
        pm = qvariant_cast<QPixmap>(data);
    } else if (data.type() == QVariant::ByteArray) {
        pm.loadFromData(data.toByteArray());
    }

    if (pm.isNull()) {
        QString context;
#ifndef QT_NO_TEXTBROWSER
        QTextBrowser *browser = qobject_cast<QTextBrowser *>(doc->parent());
        if (browser)
            context = browser->source().toString();
#endif
        QImage img;
        if (QTextImageHandler::externalLoader)
            img = QTextImageHandler::externalLoader(name, context);

        if (img.isNull()) { // try direct loading
            name = format.name(); // remove qrc:/ prefix again
            if (name.isEmpty() || !img.load(name))
                return QPixmap(QLatin1String(":/trolltech/styles/commonstyle/images/file-16.png"));
        }
        pm = QPixmap::fromImage(img);
        doc->addResource(QTextDocument::ImageResource, url, pm);
    }

    return pm;
}

static QSize getPixmapSize(QTextDocument *doc, const QTextImageFormat &format)
{
    QPixmap pm;

    const bool hasWidth = format.hasProperty(QTextFormat::ImageWidth);
    const int width = qRound(format.width());
    const bool hasHeight = format.hasProperty(QTextFormat::ImageHeight);
    const int height = qRound(format.height());

    QSize size(width, height);
    if (!hasWidth || !hasHeight) {
        pm = getPixmap(doc, format);
        if (!hasWidth)
            size.setWidth(pm.width());
        if (!hasHeight)
            size.setHeight(pm.height());
    }

    qreal scale = 1.0;
    QPaintDevice *pdev = doc->documentLayout()->paintDevice();
    if (pdev) {
        extern int qt_defaultDpi();
        if (pm.isNull())
            pm = getPixmap(doc, format);
        if (!pm.isNull())
            scale = qreal(pdev->logicalDpiY()) / qreal(qt_defaultDpi());
    }
    size *= scale;

    return size;
}

QTextImageHandler::QTextImageHandler(QObject *parent)
    : QObject(parent)
{
}

QSizeF QTextImageHandler::intrinsicSize(QTextDocument *doc, int posInDocument, const QTextFormat &format)
{
    Q_UNUSED(posInDocument)
    const QTextImageFormat imageFormat = format.toImageFormat();

    return getPixmapSize(doc, imageFormat);
}

void QTextImageHandler::drawObject(QPainter *p, const QRectF &rect, QTextDocument *doc, int posInDocument, const QTextFormat &format)
{
    Q_UNUSED(posInDocument)
    const QTextImageFormat imageFormat = format.toImageFormat();
    const QPixmap pixmap = getPixmap(doc, imageFormat);

    p->drawPixmap(rect, pixmap, pixmap.rect());
}