When toggling provider button, check if provider can be used by checking if user is logged-in, it this is necessary to make the provider work

src/globalsearch/globalsearch.cpp

@@ -223,16 +223,26 @@ int GlobalSearch::LoadTracksAsync(const SearchProvider::Result& result) {
   return id;
 }
 
-void GlobalSearch::SetProviderEnabled(const SearchProvider* const_provider,
+bool GlobalSearch::SetProviderEnabled(const SearchProvider* const_provider,
                                       bool enabled) {
   SearchProvider* provider = const_cast<SearchProvider*>(const_provider);
   if (!providers_.contains(provider))
-    return;
+    return true;
 
   if (providers_[provider].enabled_ != enabled) {
-    providers_[provider].enabled_ = enabled;
-    emit ProviderToggled(provider, enabled);
+    // If we try to enable this provider but it is not logged in, don't change
+    // state, and show configuration menu, if any
+    if (enabled && !provider->IsLoggedIn()) {
+      provider->ShowConfig();
+      return false;
+    } else {
+      providers_[provider].enabled_ = enabled;
+      emit ProviderToggled(provider, enabled);
+      return true;
+    }
+    // TODO: save providers
   }
+  return true;
 }
 
 bool GlobalSearch::is_provider_enabled(const SearchProvider* const_provider) const {

src/globalsearch/globalsearch.h

@@ -34,7 +34,9 @@ public:
   static const char* kSettingsGroup;
 
   void AddProvider(SearchProvider* provider);
-  void SetProviderEnabled(const SearchProvider* provider, bool enabled);
+  // Try to change provider state. Returns false if we can't (e.g. we can't
+  // enable a provider because it requires the user to be logged-in)
+  bool SetProviderEnabled(const SearchProvider* provider, bool enabled);
 
   int SearchAsync(const QString& query);
   int LoadArtAsync(const SearchProvider::Result& result);

src/globalsearch/globalsearchwidget.cpp

@@ -771,5 +771,8 @@ void GlobalSearchWidget::ProviderButtonToggled(bool on) {
   if (!provider)
     return;
 
-  engine_->SetProviderEnabled(provider, on);
+  if (!engine_->SetProviderEnabled(provider, on)) {
+    // If we were not able to change provider state, toggle back provider button
+    button->toggle();
+  }
 }

src/globalsearch/groovesharksearchprovider.cpp

@@ -131,6 +131,14 @@ void GroovesharkSearchProvider::LoadTracksAsync(int id, const Result& result) {
 
 }
 
+bool GroovesharkSearchProvider::IsLoggedIn() {
+  return (service_ && service_->IsLoggedIn());
+}
+
+void GroovesharkSearchProvider::ShowConfig() {
+  service_->ShowConfig();
+}
+
 void GroovesharkSearchProvider::FetchAlbum(int id, const Result& result) {
   service_->FetchSongsForAlbum(id, result.metadata_.url());
 }

src/globalsearch/groovesharksearchprovider.h

@@ -35,6 +35,8 @@ class GroovesharkSearchProvider : public SearchProvider {
   void SearchAsync(int id, const QString& query);
   void LoadArtAsync(int id, const Result& result);
   void LoadTracksAsync(int id, const Result& result);
+  bool IsLoggedIn();
+  void ShowConfig();
 
  private slots:
   void SearchDone(int id, const SongList& songs);

src/globalsearch/searchprovider.h

@@ -94,6 +94,11 @@ public:
   // ResultsAvailable.  Must emit TracksLoaded exactly once with this ID.
   virtual void LoadTracksAsync(int id, const Result& result) = 0;
 
+  // If provider needs user login to search and play songs, this method should
+  // be reimplemented
+  virtual bool IsLoggedIn() { return true; }
+  virtual void ShowConfig() { }
+
   static QImage ScaleAndPad(const QImage& image);
 
 signals:

src/globalsearch/spotifysearchprovider.cpp

@@ -192,4 +192,15 @@ void SpotifySearchProvider::AlbumBrowseResponse(const spotify_pb::BrowseAlbumRes
   emit TracksLoaded(orig_id, mime_data);
 }
 
+bool SpotifySearchProvider::IsLoggedIn() {
+  if (server()) {
+    return service_->IsLoggedIn();
+  }
+  return false;
+}
 
+void SpotifySearchProvider::ShowConfig() {
+  if (service_) {
+    return service_->ShowConfig();
+  }
+}

src/globalsearch/spotifysearchprovider.h

@@ -35,6 +35,9 @@ public:
   void LoadArtAsync(int id, const Result& result);
   void LoadTracksAsync(int id, const Result& result);
 
+  bool IsLoggedIn();
+  void ShowConfig();
+
 private slots:
   void ServerDestroyed();
   void SearchFinishedSlot(const spotify_pb::SearchResponse& response);

src/internet/groovesharkservice.h

@@ -61,7 +61,7 @@ class GroovesharkService : public InternetService {
                                  qint64* length_nanosec);
   void Login(const QString& username, const QString& password);
   void Logout();
-  bool IsLoggedIn() { return !session_id_.isEmpty(); }
+  bool IsLoggedIn() const { return !session_id_.isEmpty(); }
   void RetrieveUserPlaylists();
   void MarkStreamKeyOver30Secs(const QString& stream_key, const QString& server_id);
   void MarkSongComplete(const QString& song_id, const QString& stream_key, const QString& server_id);
@@ -92,6 +92,9 @@ class GroovesharkService : public InternetService {
   void AlbumSearchResult(int id, SongList songs);
   void AlbumSongsLoaded(int id, SongList songs);
 
+ public slots:
+  void ShowConfig();
+
  protected:
   QModelIndex GetCurrentIndex();
 
@@ -107,7 +110,6 @@ class GroovesharkService : public InternetService {
  private slots:
   void UpdateTotalSongCount(int count);
 
-  void ShowConfig();
   void SessionCreated();
   void OpenSearchTab();
   void DoSearch();

src/internet/internetservice.h

@@ -56,6 +56,14 @@ public:
 
   virtual QString Icon() { return QString(); }
 
+  // Services which need user login will need to reimplement this method
+  virtual bool IsLoggedIn() const { return true; }
+
+public slots:
+  // Show configuration panel for services which have one
+  virtual void ShowConfig() { }
+  
+
 signals:
   void StreamError(const QString& message);
   void StreamMetadataFound(const QUrl& original_url, const Song& song);

src/internet/spotifyservice.h

@@ -68,6 +68,7 @@ public:
 
   // Persisted in the settings and updated on each Login().
   LoginState login_state() const { return login_state_; }
+  bool IsLoggedIn() const { return login_state_ == LoginState_LoggedIn; }
 
   static void SongFromProtobuf(const spotify_pb::Track& track, Song* song);
 
@@ -76,6 +77,9 @@ signals:
   void LoginFinished(bool success);
   void ImageLoaded(const QUrl& url, const QImage& image);
 
+public slots:
+  void ShowConfig();
+
 protected:
   virtual QModelIndex GetCurrentIndex();
 
@@ -104,7 +108,6 @@ private slots:
   void OpenSearchTab();
   void DoSearch();
 
-  void ShowConfig();
   void SyncPlaylist();
   void BlobDownloadFinished();