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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#include "qtextimagehandler_p.h"
#include <qbuffer.h>
#include <qguiapplication.h>
#include <qtextformat.h>
#include <qpainter.h>
#include <qdebug.h>
#include <qicon.h>
#include <qimagereader.h>
#include <qpixmapcache.h>
#include <qthread.h>
#include <qpa/qplatformintegration.h>
#include <private/qguiapplication_p.h>
#include <private/qhexstring_p.h>
#include <private/qtextengine_p.h>
#include <limits>
QT_BEGIN_NAMESPACE
using namespace Qt::StringLiterals;
static inline QUrl findAtNxFileOrResource(const QString &baseFileName,
qreal targetDevicePixelRatio,
qreal *sourceDevicePixelRatio,
QString *name)
{
// qt_findAtNxFile expects a file name that can be tested with QFile::exists.
// so if the format.name() is a file:/ or qrc:/ URL, then we need to strip away the schema.
QString localFile;
const QUrl url(baseFileName);
bool hasFileScheme = false;
bool isResource = false;
if (url.isLocalFile()) {
localFile = url.toLocalFile();
hasFileScheme = true;
} else if (baseFileName.startsWith("qrc:/"_L1)) {
// QFile::exists() can only handle ":/file.txt"
localFile = baseFileName.sliced(3);
isResource = true;
} else {
localFile = baseFileName;
isResource = baseFileName.startsWith(":/"_L1);
}
*name = qt_findAtNxFile(localFile, targetDevicePixelRatio, sourceDevicePixelRatio);
if (hasFileScheme)
return QUrl::fromLocalFile(*name);
if (isResource)
return QUrl("qrc"_L1 + *name);
return QUrl(*name);
}
static QImage getImage(QTextDocument *doc, const QTextImageFormat &format,
const qreal devicePixelRatio = 1.0, const QSizeF &size = {})
{
qreal sourcePixelRatio = 1.0;
QString name;
const QUrl url = findAtNxFileOrResource(format.name(), devicePixelRatio, &sourcePixelRatio, &name);
const QVariant data = doc->resource(QTextDocument::ImageResource, url);
// directly provided as QPixmap/QImage or already cached
if (data.userType() == QMetaType::QPixmap || data.userType() == QMetaType::QImage)
return data.value<QImage>();
// some image formats are scalable (e.g. svg) so we should not store a single
// QImage as QTextDocument::ImageResource to avoid scaling artefacts later on.
// But otoh we don't want to load them on every usage. Therefore cache the result
// in QPixmapCache
const bool canUsePixmapCache = (QThread::isMainThread()
|| QGuiApplicationPrivate::platformIntegration()->hasCapability(
QPlatformIntegration::ThreadedPixmaps));
const auto buildCacheKey = [](const QString &name, const QSizeF &size, qreal dpr) -> QString {
return QLatin1String("qt_textimagehandler_") % name
% HexString<int>(size.width())
% HexString<int>(size.height())
% HexString<qint16>(qRound(dpr * 1000));
};
const QString cacheKey = canUsePixmapCache
? buildCacheKey(name, size * devicePixelRatio, sourcePixelRatio)
: QString();
if (canUsePixmapCache) {
QPixmap pm;
if (QPixmapCache::find(cacheKey, &pm))
return pm.toImage();
}
const auto readImage = [&](auto &&content) {
QImageReader imgReader(content);
if (imgReader.canRead()) {
const bool supportsScaledSize = imgReader.supportsOption(QImageIOHandler::ScaledSize);
if (size.isValid() && supportsScaledSize)
imgReader.setScaledSize((size * devicePixelRatio).toSize());
QImage result = imgReader.read();
result.setDevicePixelRatio(sourcePixelRatio);
if (!supportsScaledSize)
doc->addResource(QTextDocument::ImageResource, url, result);
else if (canUsePixmapCache)
QPixmapCache::insert(cacheKey, QPixmap::fromImage(result));
return result;
}
return QImage();
};
QImage result;
if (data.metaType() == QMetaType::fromType<QByteArray>()) {
QByteArray ba(data.toByteArray());
QBuffer buf(&ba);
result = readImage(&buf);
}
if (result.isNull())
result = readImage(name);
if (result.isNull())
result = QImage(":/qt-project.org/styles/commonstyle/images/file-16.png"_L1);
return result;
}
static QSize getSize(QTextDocument *doc, const QTextImageFormat &format)
{
const bool hasWidth = format.hasProperty(QTextFormat::ImageWidth);
int width = qRound(format.width());
const bool hasHeight = format.hasProperty(QTextFormat::ImageHeight);
const int height = qRound(format.height());
const bool hasMaxWidth = format.hasProperty(QTextFormat::ImageMaxWidth);
const auto maxWidth = format.maximumWidth();
int effectiveMaxWidth = std::numeric_limits<int>::max();
if (hasMaxWidth) {
if (maxWidth.type() == QTextLength::PercentageLength)
effectiveMaxWidth = (doc->pageSize().width() - 2 * doc->documentMargin()) * maxWidth.value(100) / 100;
else
effectiveMaxWidth = maxWidth.rawValue();
width = qMin(effectiveMaxWidth, width);
}
QImage source;
QSize size(width, height);
if (!hasWidth || !hasHeight) {
source = getImage(doc, format);
QSizeF sourceSize = source.deviceIndependentSize();
if (sourceSize.width() > effectiveMaxWidth) {
// image is bigger than effectiveMaxWidth, scale it down
sourceSize.setHeight(effectiveMaxWidth * (sourceSize.height() / qreal(sourceSize.width())));
sourceSize.setWidth(effectiveMaxWidth);
}
if (!hasWidth) {
if (!hasHeight)
size.setWidth(sourceSize.width());
else
size.setWidth(qMin(effectiveMaxWidth, qRound(height * (sourceSize.width() / qreal(sourceSize.height())))));
}
if (!hasHeight) {
if (!hasWidth)
size.setHeight(sourceSize.height());
else
size.setHeight(qRound(width * (sourceSize.height() / qreal(sourceSize.width()))));
}
}
const QPaintDevice *pdev = doc->documentLayout()->paintDevice();
if (pdev)
size *= qreal(pdev->logicalDpiY()) / qreal(qt_defaultDpi());
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 getSize(doc, imageFormat);
}
QImage QTextImageHandler::image(QTextDocument *doc, const QTextImageFormat &imageFormat)
{
Q_ASSERT(doc != nullptr);
return getImage(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 QImage image = getImage(doc, imageFormat, p->device()->devicePixelRatio(), rect.size());
p->drawImage(rect, image, image.rect());
}
QT_END_NAMESPACE
#include "moc_qtextimagehandler_p.cpp"