plugin: create caching image manager

No need for external proc

1 files changed, 122 insertions, 0 deletions

diff --git a/plugin/src/Caelestia/cachingimagemanager.cpp b/plugin/src/Caelestia/cachingimagemanager.cpp
new file mode 100644
index 0000000..d557203
--- /dev/null
+++ b/plugin/src/Caelestia/cachingimagemanager.cpp
@@ -0,0 +1,122 @@
+#include "cachingimagemanager.hpp"
+
+#include <qobject.h>
+#include <QtQuick/QQuickItem>
+#include <QtQuick/QQuickWindow>
+#include <QCryptographicHash>
+#include <QThreadPool>
+#include <QFile>
+
+qreal CachingImageManager::effectiveScale() const {
+    if (m_item->window() && m_item->window()->screen()) {
+        return m_item->window()->screen()->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;
+    }
+
+    m_item = item;
+    emit itemChanged();
+}
+
+QUrl CachingImageManager::cacheDir() const {
+    return m_cacheDir;
+}
+
+void CachingImageManager::setCacheDir(const QUrl& cacheDir) {
+    if (m_cacheDir == cacheDir) {
+        return;
+    }
+
+    m_cacheDir = cacheDir;
+    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()) {
+        QThreadPool::globalInstance()->start([path, this] {
+            const QString filename = QString("%1@%2x%3.png")
+                .arg(sha256sum(path))
+                .arg(effectiveWidth())
+                .arg(effectiveHeight());
+
+            m_cachePath = m_cacheDir.resolved(QUrl(filename));
+            emit cachePathChanged();
+
+            if (!m_cachePath.isLocalFile()) {
+                qWarning() << "CachingImageManager::setPath: cachePath" << m_cachePath << "is not a local file";
+                return;
+            }
+
+            if (QFile::exists(m_cachePath.toLocalFile())) {
+                QMetaObject::invokeMethod(m_item, [this]() {
+                    m_item->setProperty("source", m_cachePath);
+                }, Qt::QueuedConnection);
+
+                m_usingCache = true;
+                emit usingCacheChanged();
+            } else {
+                QMetaObject::invokeMethod(m_item, [path, this]() {
+                    m_item->setProperty("source", QUrl::fromLocalFile(path));
+                }, Qt::QueuedConnection);
+
+                m_usingCache = false;
+                emit usingCacheChanged();
+            }
+        });
+    }
+}
+
+QUrl CachingImageManager::cachePath() const {
+    return m_cachePath;
+}
+
+bool CachingImageManager::usingCache() const {
+    return m_usingCache;
+}
+
+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();
+}