internet: Add common InternetService::ConfigRequired() method.

This will allow some common handling of unconfigured services.

src/internet/core/cloudfileservice.cpp

@@ -83,7 +83,7 @@ QStandardItem* CloudFileService::CreateRootItem() {
 void CloudFileService::LazyPopulate(QStandardItem* item) {
   switch (item->data(InternetModel::Role_Type).toInt()) {
     case InternetModel::Type_Service:
-      if (!has_credentials()) {
+      if (ConfigRequired()) {
         ShowConfig();
       } else {
         Connect();

src/internet/core/cloudfileservice.h

@@ -49,6 +49,7 @@ class CloudFileService : public InternetService {
   virtual bool has_credentials() const = 0;
   bool is_indexing() const { return indexing_task_id_ != -1; }
 
+  bool ConfigRequired() override { return !has_credentials(); }
  signals:
   void AllIndexingTasksFinished();
 

src/internet/core/internetservice.h

@@ -88,6 +88,8 @@ class InternetService : public QObject {
 
   virtual QString Icon() { return QString(); }
 
+  virtual bool ConfigRequired() { return false; }
+
  signals:
   void StreamError(const QString& message);
   void StreamMetadataFound(const QUrl& original_url, const Song& song);

src/internet/digitally/digitallyimportedservicebase.cpp

@@ -126,7 +126,7 @@ void DigitallyImportedServiceBase::RefreshStreamsFinished(QNetworkReply* reply,
 void DigitallyImportedServiceBase::PopulateStreams() {
   if (root_->hasChildren()) root_->removeRows(0, root_->rowCount());
 
-  if (!is_premium_account()) {
+  if (ConfigRequired()) {
     ShowConfig();
     return;
   }

src/internet/digitally/digitallyimportedservicebase.h

@@ -64,6 +64,8 @@ class DigitallyImportedServiceBase : public InternetService {
   void SongFromChannel(const DigitallyImportedClient::Channel& channel,
                        Song* song) const;
 
+  bool ConfigRequired() override { return !is_premium_account(); }
+
  public slots:
   void ShowConfig() override;
 

src/internet/spotify/spotifyservice.h

@@ -92,6 +92,8 @@ class SpotifyService : public InternetService {
   LoginState login_state() const { return login_state_; }
   bool IsLoggedIn() const { return login_state_ == LoginState_LoggedIn; }
 
+  bool ConfigRequired() override { return !IsLoggedIn(); }
+
   static void SongFromProtobuf(const cpb::spotify::Track& track, Song* song);
 
  signals:

src/internet/subsonic/subsonicservice.cpp

@@ -168,7 +168,7 @@ void SubsonicService::LazyPopulate(QStandardItem* item) {
   switch (item->data(InternetModel::Role_Type).toInt()) {
     case InternetModel::Type_Service:
       library_model_->Init();
-      if (login_state() != LoginState_Loggedin) {
+      if (ConfigRequired()) {
         ShowConfig();
       } else if (total_song_count_ == 0 && !load_database_task_id_) {
         ReloadDatabase();

src/internet/subsonic/subsonicservice.h

@@ -103,6 +103,10 @@ class SubsonicService : public InternetService {
 
   LoginState login_state() const { return login_state_; }
 
+  bool ConfigRequired() override {
+    return login_state() != LoginState_Loggedin;
+  }
+
   // Subsonic API methods
   void Ping();