Add an Unsubscribe button to the Add Podcast dialog

src/podcasts/addpodcastdialog.cpp

@@ -43,12 +43,17 @@ AddPodcastDialog::AddPodcastDialog(Application* app, QWidget* parent)
   connect(ui_->provider_list, SIGNAL(currentRowChanged(int)), SLOT(ChangePage(int)));
   connect(ui_->details, SIGNAL(LoadingFinished()), fader_, SLOT(StartFade()));
 
-  // Create an Add Podcast button
+  // Create Add and Remove Podcast buttons
   add_button_ = new QPushButton(IconLoader::Load("list-add"), tr("Add Podcast"), this);
   add_button_->setEnabled(false);
   connect(add_button_, SIGNAL(clicked()), SLOT(AddPodcast()));
   ui_->button_box->addButton(add_button_, QDialogButtonBox::ActionRole);
 
+  remove_button_ = new QPushButton(IconLoader::Load("list-remove"), tr("Unsubscribe"), this);
+  remove_button_->setEnabled(false);
+  connect(remove_button_, SIGNAL(clicked()), SLOT(RemovePodcast()));
+  ui_->button_box->addButton(remove_button_, QDialogButtonBox::ActionRole);
+
   // Add providers
   AddPage(new AddPodcastByUrl(app, this));
   AddPage(new GPodderTopTagsPage(app, this));
@@ -91,23 +96,48 @@ void AddPodcastDialog::ChangePage(int index) {
 }
 
 void AddPodcastDialog::ChangePodcast(const QModelIndex& current) {
+  // If the selected item is invalid or not a podcast, hide the details pane.
   if (!current.isValid() ||
       current.data(PodcastDiscoveryModel::Role_Type).toInt() !=
           PodcastDiscoveryModel::Type_Podcast) {
     ui_->details_scroll_area->hide();
+    add_button_->setEnabled(false);
+    remove_button_->setEnabled(false);
     return;
   }
 
+  current_podcast_ = current.data(PodcastDiscoveryModel::Role_Podcast).value<Podcast>();
+
+  // Also hide the details pane if this podcast isn't valid.
+  if (!current_podcast_.url().isValid()) {
+    ui_->details_scroll_area->hide();
+    add_button_->setEnabled(false);
+    remove_button_->setEnabled(false);
+    return;
+  }
+
+  // Start the blur+fade if there's already a podcast in the details pane.
   if (ui_->details_scroll_area->isVisible()) {
     fader_->StartBlur();
   } else {
     ui_->details_scroll_area->show();
   }
 
-  current_podcast_ = current.data(PodcastDiscoveryModel::Role_Podcast).value<Podcast>();
+  // Update the details pane
   ui_->details->SetPodcast(current_podcast_);
 
-  add_button_->setEnabled(current_podcast_.url().isValid());
+  // Is the user already subscribed to this podcast?
+  Podcast subscribed_podcast =
+      app_->podcast_backend()->GetSubscriptionByUrl(current_podcast_.url());
+  const bool is_subscribed = subscribed_podcast.url().isValid();
+
+  if (is_subscribed) {
+    // Use the one from the database which will contain the ID.
+    current_podcast_ = subscribed_podcast;
+  }
+
+  add_button_->setEnabled(!is_subscribed);
+  remove_button_->setEnabled(is_subscribed);
 }
 
 void AddPodcastDialog::PageBusyChanged(bool busy) {
@@ -129,4 +159,12 @@ void AddPodcastDialog::CurrentPageBusyChanged(bool busy) {
 
 void AddPodcastDialog::AddPodcast() {
   app_->podcast_backend()->Subscribe(&current_podcast_);
+  add_button_->setEnabled(false);
+  remove_button_->setEnabled(true);
+}
+
+void AddPodcastDialog::RemovePodcast() {
+  app_->podcast_backend()->Unsubscribe(current_podcast_);
+  add_button_->setEnabled(true);
+  remove_button_->setEnabled(false);
 }

src/podcasts/addpodcastdialog.h

@@ -38,6 +38,7 @@ public:
 
 private slots:
   void AddPodcast();
+  void RemovePodcast();
   void ChangePage(int index);
   void ChangePodcast(const QModelIndex& current);
 
@@ -52,6 +53,7 @@ private:
 
   Ui_AddPodcastDialog* ui_;
   QPushButton* add_button_;
+  QPushButton* remove_button_;
 
   QList<AddPodcastPage*> pages_;
   QList<bool> page_is_busy_;

src/podcasts/podcastbackend.cpp

@@ -73,6 +73,35 @@ void PodcastBackend::Subscribe(Podcast* podcast) {
   emit SubscriptionAdded(*podcast);
 }
 
+void PodcastBackend::Unsubscribe(const Podcast& podcast) {
+  // If this podcast is not already in the database, do nothing
+  if (!podcast.is_valid()) {
+    return;
+  }
+
+  QMutexLocker l(db_->Mutex());
+  QSqlDatabase db(db_->Connect());
+  ScopedTransaction t(&db);
+
+  // Remove the podcast.
+  QSqlQuery q("DELETE FROM podcasts WHERE ROWID = :id", db);
+  q.bindValue(":id", podcast.database_id());
+  q.exec();
+  if (db_->CheckErrors(q))
+    return;
+
+  // Remove all episodes in the podcast
+  q = QSqlQuery("DELETE FROM podcast_episodes WHERE podcast_id = :id", db);
+  q.bindValue(":id", podcast.database_id());
+  q.exec();
+  if (db_->CheckErrors(q))
+    return;
+
+  t.Commit();
+
+  emit SubscriptionRemoved(podcast);
+}
+
 void PodcastBackend::AddEpisodes(PodcastEpisodeList* episodes, QSqlDatabase* db) {
   QSqlQuery q("INSERT INTO podcast_episodes (" + PodcastEpisode::kColumnSpec + ")"
               " VALUES (" + PodcastEpisode::kBindSpec + ")", *db);

src/podcasts/podcastservice.cpp

@@ -97,6 +97,7 @@ QStandardItem* PodcastService::CreatePodcastItem(const Podcast& podcast) {
 
   item->setText(podcast.title());
   item->setIcon(default_icon_);
+  item->setData(QVariant::fromValue(podcast), Role_Podcast);
 
   // Load the podcast's image if it has one
   if (podcast.image_url().isValid()) {
@@ -147,4 +148,12 @@ void PodcastService::SubscriptionAdded(const Podcast& podcast) {
 }
 
 void PodcastService::SubscriptionRemoved(const Podcast& podcast) {
+  // Find the item in the model that matches this podcast.
+  for (int i=0 ; i<model_->rowCount() ; ++i) {
+    Podcast item_podcast(model_->item(i)->data(Role_Podcast).value<Podcast>());
+    if (podcast.database_id() == item_podcast.database_id()) {
+      model_->removeRow(i);
+      return;
+    }
+  }
 }

src/podcasts/podcastservice.h

@@ -46,6 +46,10 @@ public:
     Type_Episode
   };
 
+  enum Role {
+    Role_Podcast = InternetModel::RoleCount
+  };
+
   QStandardItem* CreateRootItem();
   void LazyPopulate(QStandardItem* parent);