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#include "cachingimagemanager.hpp"
#include <qobject.h>
#include <QtQuick/QQuickItem>
#include <QtQuick/QQuickWindow>
#include <QCryptographicHash>
#include <QThreadPool>
#include <QFile>
#include <QDir>
#include <QImageReader>
qreal CachingImageManager::effectiveScale() const {
if (m_item->window()) {
return m_item->window()->devicePixelRatio();
}
return 1.0;
}
int CachingImageManager::effectiveWidth() const {
int width = std::ceil(m_item->width() * effectiveScale());
m_item->setProperty("sourceWidth", width);
return width;
}
int CachingImageManager::effectiveHeight() const {
int height = std::ceil(m_item->height() * effectiveScale());
m_item->setProperty("sourceHeight", height);
return height;
}
QQuickItem* CachingImageManager::item() const {
return m_item;
}
void CachingImageManager::setItem(QQuickItem* item) {
if (m_item == item) {
return;
}
if (m_widthConn) {
disconnect(m_widthConn);
}
if (m_heightConn) {
disconnect(m_heightConn);
}
m_item = item;
emit itemChanged();
if (item) {
m_widthConn = connect(item, &QQuickItem::widthChanged, this, [this]() { updateSource(); });
m_heightConn = connect(item, &QQuickItem::heightChanged, this, [this]() { updateSource(); });
updateSource();
}
}
QUrl CachingImageManager::cacheDir() const {
return m_cacheDir;
}
void CachingImageManager::setCacheDir(const QUrl& cacheDir) {
if (m_cacheDir == cacheDir) {
return;
}
m_cacheDir = cacheDir;
if (!m_cacheDir.path().endsWith("/")) {
m_cacheDir.setPath(m_cacheDir.path() + "/");
}
emit cacheDirChanged();
}
QString CachingImageManager::path() const {
return m_path;
}
void CachingImageManager::setPath(const QString& path) {
if (m_path == path) {
return;
}
m_path = path;
emit pathChanged();
if (!path.isEmpty()) {
updateSource(path);
}
}
void CachingImageManager::updateSource() {
updateSource(m_path);
}
void CachingImageManager::updateSource(const QString& path) {
if (path.isEmpty()) {
return;
}
QThreadPool::globalInstance()->start([path, this] {
const QString sha = sha256sum(path);
QMetaObject::invokeMethod(this, [path, sha, this]() {
int width = effectiveWidth();
int height = effectiveHeight();
const QString filename = QString("%1@%2x%3.png").arg(sha).arg(width).arg(height);
const QUrl cache = m_cacheDir.resolved(QUrl(filename));
if (m_cachePath == cache) {
return;
}
m_cachePath = cache;
emit cachePathChanged();
if (!cache.isLocalFile()) {
qWarning() << "CachingImageManager::updateSource: cachePath" << cache << "is not a local file";
return;
}
bool cacheExists = QFile::exists(cache.toLocalFile());
if (cacheExists) {
m_item->setProperty("source", cache);
} else {
m_item->setProperty("source", QUrl::fromLocalFile(path));
createCache(path, cache.toLocalFile(), QSize(width, height));
}
}, Qt::QueuedConnection);
});
}
QUrl CachingImageManager::cachePath() const {
return m_cachePath;
}
void CachingImageManager::createCache(const QString& path, const QString& cache, const QSize& size) const {
QThreadPool::globalInstance()->start([path, cache, size] {
QImageReader reader(path);
QSize imgSize = reader.size();
if (!imgSize.isValid()) {
qWarning() << "CachingImageManager::createCache: unable to get size of" << path;
return;
}
qreal scale = std::max(
qreal(size.width()) / imgSize.width(),
qreal(size.height()) / imgSize.height()
);
QSizeF scaledSize(imgSize.width() * scale, imgSize.height() * scale);
qreal xOff = (scaledSize.width() - size.width()) / 2.0;
qreal yOff = (scaledSize.height() - size.height()) / 2.0;
reader.setScaledSize(scaledSize.toSize());
reader.setScaledClipRect(QRectF(xOff, yOff, size.width(), size.height()).toRect());
QImage image = reader.read();
if (image.isNull()) {
qWarning() << "CachingImageManager::createCache: failed to read" << path;
return;
}
const QString parent = QFileInfo(cache).absolutePath();
if (!QDir().mkpath(parent) || !image.save(cache)) {
qWarning() << "CachingImageManager::createCache: failed to save to" << cache;
}
});
}
QString CachingImageManager::sha256sum(const QString& path) const {
QFile file(path);
if (!file.open(QIODevice::ReadOnly)) {
qWarning() << "CachingImageManager::sha256sum: failed to open" << path;
return "";
}
QCryptographicHash hash(QCryptographicHash::Sha256);
hash.addData(&file);
file.close();
return hash.result().toHex();
}
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