void QQuickImageBase::resolve2xLocalFile(const QUrl &url, qreal targetDevicePixelRatio, QUrl *sourceUrl, qreal *sourceDevicePixelRatio)
{
Q_ASSERT(sourceUrl);
Q_ASSERT(sourceDevicePixelRatio);
// Bail out if "@2x" image loading is disabled, don't change the source url or devicePixelRatio.
static const bool disable2xImageLoading = !qEnvironmentVariableIsEmpty("QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING");
if (disable2xImageLoading)
return;
QString localFile = QQmlFile::urlToLocalFileOrQrc(url);
// Non-local file path: @2x loading is not supported.
if (localFile.isEmpty())
return;
// Special case: the url in the QML source refers directly to an "@2x" file.
int atLocation = localFile.lastIndexOf(QLatin1Char('@'));
if (atLocation > 0 && atLocation + 3 < localFile.size()) {
if (localFile[atLocation + 1].isDigit()
&& localFile[atLocation + 2] == QLatin1Char('x')
&& localFile[atLocation + 3] == QLatin1Char('.')) {
*sourceDevicePixelRatio = localFile[atLocation + 1].digitValue();
return;
}
}
// Look for an @2x version
QString localFileX = qt_findAtNxFile(localFile, targetDevicePixelRatio, sourceDevicePixelRatio);
if (localFileX != localFile)
*sourceUrl = QUrl::fromLocalFile(localFileX);
}
QPixmap loadPixmap(const QString &path)
{
qreal ratio = 1.0;
QPixmap pixmap;
const qreal devicePixelRatio = qApp->devicePixelRatio();
if (!qFuzzyCompare(ratio, devicePixelRatio)) {
QImageReader reader;
reader.setFileName(qt_findAtNxFile(path, devicePixelRatio, &ratio));
if (reader.canRead()) {
reader.setScaledSize(reader.size() * (devicePixelRatio / ratio));
pixmap = QPixmap::fromImage(reader.read());
pixmap.setDevicePixelRatio(devicePixelRatio);
}
} else {
pixmap.load(path);
}
return pixmap;
}
/*! Adds an image from the file with the given \a fileName to the
icon, as a specialization for \a size, \a mode and \a state. The
file will be loaded on demand. Note: custom icon engines are free
to ignore additionally added pixmaps.
If \a fileName contains a relative path (e.g. the filename only)
the relevant file must be found relative to the runtime working
directory.
The file name can be either refer to an actual file on disk or to
one of the application's embedded resources. See the
\l{resources.html}{Resource System} overview for details on how to
embed images and other resource files in the application's
executable.
Use the QImageReader::supportedImageFormats() and
QImageWriter::supportedImageFormats() functions to retrieve a
complete list of the supported file formats.
If a high resolution version of the image exists (identified by
the suffix \c @2x on the base name), it is automatically loaded
and added with the \e{device pixel ratio} set to a value of 2.
This can be disabled by setting the environment variable
\c QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING (see QImageReader).
\note When you add a non-empty filename to a QIcon, the icon becomes
non-null, even if the file doesn't exist or points to a corrupt file.
\sa addPixmap(), QPixmap::devicePixelRatio()
*/
void QIcon::addFile(const QString &fileName, const QSize &size, Mode mode, State state)
{
if (fileName.isEmpty())
return;
if (!d) {
#ifndef QT_NO_LIBRARY
QFileInfo info(fileName);
QString suffix = info.suffix();
if (!suffix.isEmpty()) {
// first try version 2 engines..
const int index = loader()->indexOf(suffix);
if (index != -1) {
if (QIconEnginePlugin *factory = qobject_cast<QIconEnginePlugin*>(loader()->instance(index))) {
if (QIconEngine *engine = factory->create(fileName)) {
d = new QIconPrivate;
d->engine = engine;
}
}
}
}
#endif
// ...then fall back to the default engine
if (!d) {
d = new QIconPrivate;
d->engine = new QPixmapIconEngine;
}
} else {
detach();
}
d->engine->addFile(fileName, size, mode, state);
// Check if a "@Nx" file exists and add it.
QString atNxFileName = qt_findAtNxFile(fileName, qApp->devicePixelRatio());
if (atNxFileName != fileName)
d->engine->addFile(atNxFileName, size, mode, state);
}
