QImage NemoThumbnailProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
{
setupCache();
// needed for stupid things like gallery model, which pass us a url
if (id.startsWith("file://")) {
// qWarning() << Q_FUNC_INFO << "Removing file:// prefix, before: " << id;
QString &nid = const_cast<QString &>(id);
nid = nid.remove(0, 7);
}
TDEBUG() << Q_FUNC_INFO << "Requested image: " << id << " with size " << requestedSize;
// sourceSize should indicate what size thumbnail you want. i.e. if you want a 120x120px thumbnail,
// set sourceSize: Qt.size(120, 120).
if (!requestedSize.isValid())
qFatal("You must request a sourceSize whenever you use nemoThumbnail");
if (size)
*size = requestedSize;
QByteArray hashData = cacheKey(id, requestedSize);
QImage img = attemptCachedServe(id, hashData);
if (!img.isNull()) {
TDEBUG() << Q_FUNC_INFO << "Read " << id << " from cache";
return img;
}
return generateThumbnail(id, hashData, requestedSize);
}
QImage FileThumbnailImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
{
setupCache();
// needed for stupid things like gallery model, which pass us a url
if (id.startsWith("file://")) {
qWarning() << Q_FUNC_INFO << "Removing file:// prefix, before: " << id;
QString &nid = const_cast<QString &>(id);
nid = nid.remove(0, 7);
}
qDebug() << Q_FUNC_INFO << "Requested image: " << id << " with size " << requestedSize;
// sourceSize should indicate what size thumbnail you want. i.e. if you want a 120x120px thumbnail,
// set sourceSize: Qt.size(120, 120).
if (!requestedSize.isValid())
qFatal("You must request a sourceSize whenever you use nemoThumbnail");
if (size)
*size = requestedSize;
QByteArray hashData = cacheKey(id, requestedSize);
QImage img = attemptCachedServe(hashData);
if (!img.isNull()) {
qDebug() << Q_FUNC_INFO << "Read " << id << " from cache";
return img;
}
// cache couldn't satisfy us.
// step 1: read source image in
QImageReader ir(id);
img = ir.read();
// don't pollute the cache with false positives
if (img.isNull())
return QImage();
if (img.size() == requestedSize)
return img;
// step 2: scale to target size
if (img.height() == img.width()) {
// in the case of a squared image, there's no need to crop
img = img.scaled(requestedSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
} else if (img.height() >= requestedSize.height() && img.width() >= requestedSize.width()) {
// if the image is larger than the desired size (on both dimensions)
// then crop, and scale down
if (img.width() < img.height()) {
int cropPosition = (img.height() - img.width()) / 2;
img = img.copy(0, cropPosition, img.width(), img.width());
img = img.scaledToWidth(requestedSize.width(), Qt::SmoothTransformation);
} else {
int cropPosition = (img.width() - img.height()) / 2;
img = img.copy(cropPosition, 0, img.height(), img.height());
img = img.scaledToHeight(requestedSize.height(), Qt::SmoothTransformation);
}
} else if ((img.width() <= requestedSize.width() && img.height() >= requestedSize.height()) ||
(img.width() >= requestedSize.width() && img.height() <= requestedSize.height())) {
// if the image is smaller than the desired size on one dimension, scale it up,
// then crop down to thumbnail size.
if (img.width() <= requestedSize.width() && img.height() >= requestedSize.height()) {
img = img.scaledToWidth(requestedSize.width(), Qt::SmoothTransformation);
int cropPosition = (img.height() - img.width()) / 2;
img = img.copy(0, cropPosition, img.width(), img.width());
} else {
img = img.scaledToHeight(requestedSize.height(), Qt::SmoothTransformation);
int cropPosition = (img.width() - img.height()) / 2;
img = img.copy(cropPosition, 0, img.height(), img.height());
}
} else {
// if the image is smaller on both dimensions, scale it up, and use the requested
// size to do the cropping
if (img.width() < img.height()) {
img = img.scaledToWidth(requestedSize.width(), Qt::SmoothTransformation);
int cropPosition = (img.height() - requestedSize.height()) / 2;
img = img.copy(0, cropPosition, img.width(), img.width());
} else {
img = img.scaledToHeight(requestedSize.height(), Qt::SmoothTransformation);
int cropPosition = (img.width() - requestedSize.width()) / 2;
img = img.copy(cropPosition, 0, img.height(), img.height());
}
}
// step 3: write to cache for next time
writeCacheFile(hashData, img);
qDebug() << Q_FUNC_INFO << "Wrote " << id << " to cache";
return img;
}
