Add option to scrobbler setting for showing login error

Fixes #430

src/scrobbler/audioscrobbler.cpp

@@ -46,7 +46,9 @@ AudioScrobbler::AudioScrobbler(Application *app, QObject *parent) :
   offline_(false),
   scrobble_button_(false),
   love_button_(false),
-  submit_delay_(0)
+  submit_delay_(0),
+  prefer_albumartist_(false),
+  show_auth_error_(false)
   {
 
   scrobbler_services_->AddService(new LastFMScrobbler(app_, scrobbler_services_));
@@ -73,6 +75,7 @@ void AudioScrobbler::ReloadSettings() {
   love_button_ = s.value("love_button", false).toBool();
   submit_delay_ = s.value("submit", 0).toInt();
   prefer_albumartist_ = s.value("albumartist", false).toBool();
+  show_auth_error_ = s.value("show_auth_error", true).toBool();
   s.endGroup();
 
   emit ScrobblingEnabledChanged(enabled_);

src/scrobbler/audioscrobbler.h

@@ -46,6 +46,7 @@ class AudioScrobbler : public QObject {
   bool LoveButton() const { return love_button_; }
   int SubmitDelay() const { return submit_delay_; }
   bool PreferAlbumArtist() const { return prefer_albumartist_; }
+  bool ShowAuthError() const { return show_auth_error_; }
 
   void UpdateNowPlaying(const Song &song);
   void ClearPlaying();
@@ -85,6 +86,7 @@ class AudioScrobbler : public QObject {
   bool love_button_;
   int submit_delay_;
   bool prefer_albumartist_;
+  bool show_auth_error_;
 
 };
 

src/scrobbler/scrobblingapi20.cpp

@@ -525,7 +525,7 @@ void ScrobblingAPI20::Scrobble(const Song &song) {
   if (app_->scrobbler()->IsOffline()) return;
 
   if (!IsAuthenticated()) {
-    emit ErrorMessage(tr("Scrobbler %1 is not authenticated!").arg(name_));
+    if (app_->scrobbler()->ShowAuthError()) { emit ErrorMessage(tr("Scrobbler %1 is not authenticated!").arg(name_)); }
     return;
   }
 

src/settings/scrobblersettingspage.cpp

@@ -94,6 +94,7 @@ void ScrobblerSettingsPage::Load() {
   ui_->checkbox_offline->setChecked(scrobbler_->IsOffline());
   ui_->spinbox_submit->setValue(scrobbler_->SubmitDelay());
   ui_->checkbox_albumartist->setChecked(scrobbler_->PreferAlbumArtist());
+  ui_->checkbox_show_auth_error->setChecked(scrobbler_->ShowAuthError());
 
   ui_->checkbox_lastfm_enable->setChecked(lastfmscrobbler_->IsEnabled());
   ui_->checkbox_lastfm_https->setChecked(lastfmscrobbler_->IsUseHTTPS());
@@ -119,6 +120,7 @@ void ScrobblerSettingsPage::Save() {
   s.setValue("offline", ui_->checkbox_offline->isChecked());
   s.setValue("submit", ui_->spinbox_submit->value());
   s.setValue("albumartist", ui_->checkbox_albumartist->isChecked());
+  s.setValue("show_auth_error", ui_->checkbox_show_auth_error->isChecked());
   s.endGroup();
 
   s.beginGroup(LastFMScrobbler::kSettingsGroup);

src/settings/scrobblersettingspage.ui

@@ -109,6 +109,13 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QCheckBox" name="checkbox_show_auth_error">
+     <property name="text">
+      <string>Show error dialog if scrobbler is enabled without being authenticated</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QGroupBox" name="groupbox_lastfm">
      <property name="title">