Partial revert commit af67de8

src/playlist/playlist.cpp

@@ -1314,15 +1314,17 @@ void Playlist::Restore() {
   collection_items_by_id_.clear();
 
   cancel_restore_ = false;
-
-  (void)QtConcurrent::run([=]() { ItemsLoaded(backend_->GetPlaylistItems(id_)); });
+  QFuture<QList<PlaylistItemPtr>> future = QtConcurrent::run(backend_, &PlaylistBackend::GetPlaylistItems, id_);
+  NewClosure(future, this, SLOT(ItemsLoaded(QFuture<PlaylistItemList>)), future);
 
 }
 
-void Playlist::ItemsLoaded(PlaylistItemList items) {
+void Playlist::ItemsLoaded(QFuture<PlaylistItemList> future) {
 
   if (cancel_restore_) return;
 
+  PlaylistItemList items = future.result();
+
   // Backend returns empty elements for collection items which it couldn't match (because they got deleted); we don't need those
   QMutableListIterator<PlaylistItemPtr> it(items);
   while (it.hasNext()) {
@@ -1351,7 +1353,7 @@ void Playlist::ItemsLoaded(PlaylistItemList items) {
 
   // Should we gray out deleted songs asynchronously on startup?
   if (greyout) {
-    (void)QtConcurrent::run([=]() { InvalidateDeletedSongs(); });
+    QtConcurrent::run(this, &Playlist::InvalidateDeletedSongs);
   }
 
   emit PlaylistLoaded();

src/playlist/playlist.h

@@ -29,6 +29,7 @@
 #include <QAbstractItemModel>
 #include <QAbstractListModel>
 #include <QPersistentModelIndex>
+#include <QFuture>
 #include <QList>
 #include <QMap>
 #include <QMultiMap>
@@ -348,7 +349,7 @@ class Playlist : public QAbstractListModel {
   void QueueLayoutChanged();
   void SongSaveComplete(TagReaderReply *reply, const QPersistentModelIndex &index);
   void ItemReloadComplete(const QPersistentModelIndex &index);
-  void ItemsLoaded(PlaylistItemList items);
+  void ItemsLoaded(QFuture<PlaylistItemList> future);
   void SongInsertVetoListenerDestroyed();
   void AlbumCoverLoaded(const Song &song, const AlbumCoverLoaderResult &result);
 

src/playlist/playlistmanager.cpp

@@ -42,6 +42,7 @@
 #include <QtDebug>
 
 #include "core/application.h"
+#include "core/closure.h"
 #include "core/logging.h"
 #include "core/player.h"
 #include "core/utilities.h"
@@ -210,11 +211,18 @@ void PlaylistManager::Save(int id, const QString &filename, Playlist::Path path_
   }
   else {
     // Playlist is not in the playlist manager: probably save action was triggered from the left side bar and the playlist isn't loaded.
-    (void)QtConcurrent::run([=]() { parser_->Save(playlist_backend_->GetPlaylistSongs(id), filename, path_type); });
+    QFuture<QList<Song>> future = QtConcurrent::run(playlist_backend_, &PlaylistBackend::GetPlaylistSongs, id);
+    NewClosure(future, this, SLOT(ItemsLoadedForSavePlaylist(QFuture<SongList>, QString, Playlist::Path)), future, filename, path_type);
   }
 
 }
 
+void PlaylistManager::ItemsLoadedForSavePlaylist(QFuture<SongList> future, const QString &filename, Playlist::Path path_type) {
+
+  parser_->Save(future.result(), filename, path_type);
+
+}
+
 void PlaylistManager::SaveWithUI(int id, const QString &playlist_name) {
 
   QSettings settings;

src/playlist/playlistmanager.h

@@ -215,6 +215,7 @@ class PlaylistManager : public PlaylistManagerInterface {
   void OneOfPlaylistsChanged();
   void UpdateSummaryText();
   void SongsDiscovered(const SongList& songs);
+  void ItemsLoadedForSavePlaylist(QFuture<SongList> future, const QString& filename, Playlist::Path path_type);
   void PlaylistLoaded();
 
  private:

src/playlist/songloaderinserter.cpp

@@ -83,7 +83,7 @@ void SongLoaderInserter::Load(Playlist *destination, int row, bool play_now, boo
     deleteLater();
   }
   else {
-    (void)QtConcurrent::run([=]{ AsyncLoad(); });
+    QtConcurrent::run(this, &SongLoaderInserter::AsyncLoad);
   }
 }