dataengines/potd: Use PotdProviderData to store information for SaveImageThread::done

As the number of roles increases, it's necessary to change the argument
type to make it possible to convey more information in the argument.

wallpapers/potd/plugins/cachedprovider.cpp

@@ -39,7 +39,10 @@ void SaveImageThread::run()
 {
     const QString path = CachedProvider::identifierToPath(m_identifier);
     m_image.save(path, "JPEG");
-    Q_EMIT done(m_identifier, path, m_image);
+    PotdProviderData data;
+    data.wallpaperImage = m_image;
+    data.wallpaperLocalUrl = path;
+    Q_EMIT done(m_identifier, data);
 }
 
 QString CachedProvider::identifierToPath(const QString &identifier)

wallpapers/potd/plugins/cachedprovider.h

@@ -79,7 +79,7 @@ public:
     void run() override;
 
 Q_SIGNALS:
-    void done(const QString &source, const QString &path, const QImage &img);
+    void done(const QString &source, const PotdProviderData &data);
 
 private:
     QImage m_image;

wallpapers/potd/plugins/potdprovidermodel.cpp

@@ -30,6 +30,8 @@ PotdProviderModel::PotdProviderModel(QObject *parent)
 
     connect(&m_checkDatesTimer, &QTimer::timeout, this, &PotdProviderModel::forceUpdateSource);
     m_checkDatesTimer.setInterval(10min); // check every 10 minutes
+
+    qRegisterMetaType<PotdProviderData>();
 }
 
 int PotdProviderModel::rowCount(const QModelIndex &parent) const
@@ -337,11 +339,11 @@ void PotdProviderModel::slotFinished(PotdProvider *provider)
     provider->deleteLater();
 }
 
-void PotdProviderModel::slotCachingFinished(const QString &source, const QString &path, const QImage &img)
+void PotdProviderModel::slotCachingFinished(const QString &source, const PotdProviderData &data)
 {
     Q_UNUSED(source)
-    setImage(img);
-    setLocalUrl(path);
+    setImage(data.wallpaperImage);
+    setLocalUrl(data.wallpaperLocalUrl);
 }
 
 void PotdProviderModel::slotError(PotdProvider *provider)

wallpapers/potd/plugins/potdprovidermodel.h

@@ -92,7 +92,7 @@ Q_SIGNALS:
 
 private Q_SLOTS:
     void slotFinished(PotdProvider *);
-    void slotCachingFinished(const QString &source, const QString &path, const QImage &img);
+    void slotCachingFinished(const QString &source, const PotdProviderData &data);
     void slotError(PotdProvider *);
     void slotPrepareForSleep(bool sleep);