flatpak: delay app size calculation

Only do it when we need it instead of fetching them all at start.

libdiscover/backends/FlatpakBackend/FlatpakBackend.cpp

@@ -541,9 +541,6 @@ void FlatpakBackend::addResource(FlatpakResource *resource)
 
     updateAppState(resource);
 
-    // This will update also metadata (required runtime)
-    updateAppSize(resource);
-
     m_resources.insert(resource->uniqueId(), resource);
     if (!resource->extends().isEmpty()) {
         m_extends.append(resource->extends());

libdiscover/backends/FlatpakBackend/FlatpakBackend.h

@@ -56,6 +56,8 @@ public:
 
     FlatpakSourcesBackend *sources() const { return m_sources; }
 
+    bool updateAppSize(FlatpakResource *resource);
+
 private Q_SLOTS:
     void onFetchMetadataFinished(FlatpakResource *resource, const QByteArray &metadata);
     void onFetchSizeFinished(FlatpakResource *resource, guint64 downloadSize, guint64 installedSize);
@@ -88,7 +90,6 @@ private:
     bool updateAppMetadata(FlatpakResource *resource);
     bool updateAppMetadata(FlatpakResource *resource, const QByteArray &data);
     bool updateAppMetadata(FlatpakResource *resource, const QString &path);
-    bool updateAppSize(FlatpakResource *resource);
     bool updateAppSizeFromRemote(FlatpakResource *resource);
     void updateAppState(FlatpakResource *resource);
 

libdiscover/backends/FlatpakBackend/FlatpakResource.cpp

@@ -350,6 +350,7 @@ QString FlatpakResource::sizeDescription()
     KFormat f;
     if (!isInstalled() || canUpgrade()) {
         if (propertyState(DownloadSize) == NotKnownYet || propertyState(InstalledSize) == NotKnownYet || propertyState(DownloadSize) == Fetching || propertyState(InstalledSize) == Fetching) {
+            qobject_cast<FlatpakBackend*>(backend())->updateAppSize(this);
             return i18n("Retrieving size information");
         } else if (propertyState(DownloadSize) == UnknownOrFailed || propertyState(InstalledSize) == UnknownOrFailed) {
             return i18n("Unknown size");