Remove most usages of QFutureWatcher

ext/libclementine-common/core/closure.h

@@ -200,6 +200,15 @@ _detail::ClosureBase* NewClosure(QFuture<T> future, QObject* receiver,
   return NewClosure(watcher, SIGNAL(finished()), receiver, slot, args...);
 }
 
+template <typename T, typename F, typename... Args>
+_detail::ClosureBase* NewClosure(QFuture<T> future, const F& callback,
+                                 const Args&... args) {
+  QFutureWatcher<T>* watcher = new QFutureWatcher<T>;
+  watcher->setFuture(future);
+  QObject::connect(watcher, SIGNAL(finished()), watcher, SLOT(deleteLater()));
+  return NewClosure(watcher, SIGNAL(finished()), callback, args...);
+}
+
 void DoAfter(QObject* receiver, const char* slot, int msec);
 void DoAfter(std::function<void()> callback, std::chrono::milliseconds msec);
 void DoInAMinuteOrSo(QObject* receiver, const char* slot);

src/core/song.h

@@ -29,7 +29,6 @@
 #ifndef CORE_SONG_H_
 #define CORE_SONG_H_
 
-#include <QFuture>
 #include <QImage>
 #include <QMetaType>
 #include <QSharedDataPointer>

src/devices/deviceproperties.cpp

@@ -20,7 +20,6 @@
 #include <functional>
 #include <memory>
 
-#include <QFutureWatcher>
 #include <QScrollBar>
 #include <QtConcurrentRun>
 
@@ -86,9 +85,8 @@ void DeviceProperties::ShowDevice(int row) {
                              << "phone-palm-pre";
 
     for (const QString& icon_name : icon_names) {
-      QListWidgetItem* item = new QListWidgetItem(IconLoader::Load(icon_name, 
+      QListWidgetItem* item = new QListWidgetItem(
-                                                  IconLoader::Base),
+          IconLoader::Load(icon_name, IconLoader::Base), QString(), ui_->icon);
-                                                  QString(), ui_->icon);
       item->setData(Qt::UserRole, icon_name);
     }
 
@@ -226,10 +224,8 @@ void DeviceProperties::UpdateFormats() {
 
     QFuture<bool> future = QtConcurrent::run(std::bind(
         &ConnectedDevice::GetSupportedFiletypes, device, &supported_formats_));
-    QFutureWatcher<bool>* watcher = new QFutureWatcher<bool>(this);
+    NewClosure(future, this, SLOT(UpdateFormatsFinished(QFuture<bool>)),
-    watcher->setFuture(future);
+               future);
-
-    connect(watcher, SIGNAL(finished()), SLOT(UpdateFormatsFinished()));
 
     ui_->formats_stack->setCurrentWidget(ui_->formats_page_loading);
     updating_formats_ = true;
@@ -265,12 +261,10 @@ void DeviceProperties::accept() {
 
 void DeviceProperties::OpenDevice() { manager_->Connect(index_.row()); }
 
-void DeviceProperties::UpdateFormatsFinished() {
+void DeviceProperties::UpdateFormatsFinished(QFuture<bool> future) {
-  QFutureWatcher<bool>* watcher = static_cast<QFutureWatcher<bool>*>(sender());
-  watcher->deleteLater();
   updating_formats_ = false;
 
-  if (!watcher->future().result()) {
+  if (!future.result()) {
     supported_formats_.clear();
   }
 

src/devices/deviceproperties.h

@@ -19,6 +19,7 @@
 #define DEVICEPROPERTIES_H
 
 #include <QDialog>
+#include <QFuture>
 #include <QPersistentModelIndex>
 
 #include "core/song.h"
@@ -47,7 +48,7 @@ class DeviceProperties : public QDialog {
  private slots:
   void ModelChanged();
   void OpenDevice();
-  void UpdateFormatsFinished();
+  void UpdateFormatsFinished(QFuture<bool> future);
 
  private:
   Ui_DeviceProperties* ui_;

src/globalsearch/searchprovider.h

@@ -18,6 +18,7 @@
 #ifndef SEARCHPROVIDER_H
 #define SEARCHPROVIDER_H
 
+#include <QFuture>
 #include <QIcon>
 #include <QMetaType>
 #include <QObject>

src/internet/icecast/icecastservice.cpp

@@ -24,7 +24,6 @@
 #include <algorithm>
 
 #include <QDesktopServices>
-#include <QFutureWatcher>
 #include <QMenu>
 #include <QMultiHash>
 #include <QNetworkReply>
@@ -75,8 +74,8 @@ IcecastService::IcecastService(Application* app, InternetModel* parent)
 IcecastService::~IcecastService() {}
 
 QStandardItem* IcecastService::CreateRootItem() {
-  root_ = new QStandardItem(IconLoader::Load("icon_radio", 
+  root_ = new QStandardItem(IconLoader::Load("icon_radio", IconLoader::Lastfm),
-                            IconLoader::Lastfm), kServiceName);
+                            kServiceName);
   root_->setData(true, InternetModel::Role_CanLazyLoad);
   return root_;
 }
@@ -128,13 +127,9 @@ void IcecastService::DownloadDirectoryFinished(QNetworkReply* reply,
 
   QFuture<IcecastBackend::StationList> future =
       QtConcurrent::run(this, &IcecastService::ParseDirectory, reply);
-  QFutureWatcher<void>* watcher = new QFutureWatcher<void>(this);
+  NewClosure(future, this, SLOT(ParseDirectoryFinished(
-  watcher->setFuture(future);
+                               QFuture<IcecastBackend::StationList>, int)),
-  NewClosure(
-      watcher, SIGNAL(finished()), this,
-      SLOT(ParseDirectoryFinished(QFuture<IcecastBackend::StationList>, int)),
              future, task_id);
-  connect(watcher, SIGNAL(finished()), watcher, SLOT(deleteLater()));
 }
 
 namespace {

src/internet/jamendo/jamendoservice.cpp

@@ -24,7 +24,6 @@
 #include "jamendoservice.h"
 
 #include <QDesktopServices>
-#include <QFutureWatcher>
 #include <QMenu>
 #include <QMessageBox>
 #include <QNetworkReply>
@@ -146,9 +145,8 @@ JamendoService::JamendoService(Application* app, InternetModel* parent)
 JamendoService::~JamendoService() {}
 
 QStandardItem* JamendoService::CreateRootItem() {
-  QStandardItem* item =
+  QStandardItem* item = new QStandardItem(
-      new QStandardItem(IconLoader::Load("jamendo", IconLoader::Provider), 
+      IconLoader::Load("jamendo", IconLoader::Provider), kServiceName);
-                                         kServiceName);
   item->setData(true, InternetModel::Role_CanLazyLoad);
   return item;
 }
@@ -205,8 +203,7 @@ void JamendoService::DownloadDirectory() {
 void JamendoService::DownloadDirectoryProgress(qint64 received, qint64 total) {
   float progress = static_cast<float>(received) / total;
   app_->task_manager()->SetTaskProgress(load_database_task_id_,
-                                        static_cast<int>(progress * 100),
+                                        static_cast<int>(progress * 100), 100);
-                                        100);
 }
 
 void JamendoService::DownloadDirectoryFinished() {
@@ -230,9 +227,7 @@ void JamendoService::DownloadDirectoryFinished() {
 
   QFuture<void> future =
       QtConcurrent::run(this, &JamendoService::ParseDirectory, gzip);
-  QFutureWatcher<void>* watcher = new QFutureWatcher<void>();
+  NewClosure(future, this, SLOT(ParseDirectoryFinished()));
-  watcher->setFuture(future);
-  connect(watcher, SIGNAL(finished()), SLOT(ParseDirectoryFinished()));
 }
 
 void JamendoService::ParseDirectory(QIODevice* device) const {
@@ -408,9 +403,6 @@ Song JamendoService::ReadTrack(const QString& artist, const QString& album,
 }
 
 void JamendoService::ParseDirectoryFinished() {
-  QFutureWatcher<void>* watcher = static_cast<QFutureWatcher<void>*>(sender());
-  delete watcher;
-
   // show smart playlists
   library_model_->set_show_smart_playlists(true);
   library_model_->Reset();
@@ -424,14 +416,12 @@ void JamendoService::EnsureMenuCreated() {
 
   context_menu_ = new QMenu;
   context_menu_->addActions(GetPlaylistActions());
-  album_info_ = context_menu_->addAction(IconLoader::Load("view-media-lyrics", 
+  album_info_ = context_menu_->addAction(
-                                         IconLoader::Base),
+      IconLoader::Load("view-media-lyrics", IconLoader::Base),
-                                         tr("Album info on jamendo.com..."),
+      tr("Album info on jamendo.com..."), this, SLOT(AlbumInfo()));
-                                         this, SLOT(AlbumInfo()));
+  download_album_ = context_menu_->addAction(
-  download_album_ = context_menu_->addAction(IconLoader::Load("download", 
+      IconLoader::Load("download", IconLoader::Base),
-                                             IconLoader::Base),
+      tr("Download this album..."), this, SLOT(DownloadAlbum()));
-                                             tr("Download this album..."), this,
-                                             SLOT(DownloadAlbum()));
   context_menu_->addSeparator();
   context_menu_->addAction(IconLoader::Load("download", IconLoader::Base),
                            tr("Open %1 in browser").arg("jamendo.com"), this,

src/library/librarymodel.cpp

@@ -20,7 +20,6 @@
 #include <functional>
 
 #include <QFuture>
-#include <QFutureWatcher>
 #include <QIODevice>
 #include <QMetaEnum>
 #include <QNetworkCacheMetaData>
@@ -63,8 +62,6 @@ const char* LibraryModel::kSmartPlaylistsSettingsGroup =
 const int LibraryModel::kSmartPlaylistsVersion = 4;
 const int LibraryModel::kPrettyCoverSize = 32;
 const qint64 LibraryModel::kIconCacheSize = 100000000;  //~100MB
-typedef QFuture<LibraryModel::QueryResult> RootQueryFuture;
-typedef QFutureWatcher<LibraryModel::QueryResult> RootQueryWatcher;
 
 static bool IsArtistGroupBy(const LibraryModel::GroupBy by) {
   return by == LibraryModel::GroupBy_Artist ||
@@ -228,7 +225,8 @@ void LibraryModel::SongsDiscovered(const SongList& songs) {
             key = PrettyYearAlbum(qMax(0, song.year()), song.album());
             break;
           case GroupBy_OriginalYearAlbum:
-            key = PrettyYearAlbum(qMax(0, song.effective_originalyear()), song.album());
+            key = PrettyYearAlbum(qMax(0, song.effective_originalyear()),
+                                  song.album());
             break;
           case GroupBy_FileType:
             key = song.filetype();
@@ -732,18 +730,16 @@ void LibraryModel::LazyPopulate(LibraryItem* parent, bool signal) {
 }
 
 void LibraryModel::ResetAsync() {
-  RootQueryFuture future =
+  QFuture<LibraryModel::QueryResult> future =
       QtConcurrent::run(this, &LibraryModel::RunQuery, root_);
-  RootQueryWatcher* watcher = new RootQueryWatcher(this);
+  NewClosure(future, this,
-  watcher->setFuture(future);
+             SLOT(ResetAsyncQueryFinished(QFuture<LibraryModel::QueryResult>)),
-
+             future);
-  connect(watcher, SIGNAL(finished()), SLOT(ResetAsyncQueryFinished()));
 }
 
-void LibraryModel::ResetAsyncQueryFinished() {
+void LibraryModel::ResetAsyncQueryFinished(
-  RootQueryWatcher* watcher = static_cast<RootQueryWatcher*>(sender());
+    QFuture<LibraryModel::QueryResult> future) {
-  const struct QueryResult result = watcher->result();
+  const struct QueryResult result = future.result();
-  watcher->deleteLater();
 
   BeginReset();
   root_->lazy_loaded = true;
@@ -960,9 +956,10 @@ LibraryItem* LibraryModel::ItemFromQuery(GroupBy type, bool signal,
       item->metadata.set_album(row.value(2).toString());
       item->metadata.set_grouping(row.value(3).toString());
       effective_originalyear = qMax(0, item->metadata.effective_originalyear());
-      item->key = PrettyYearAlbum(effective_originalyear, item->metadata.album());
+      item->key =
-      item->sort_text = SortTextForNumber(effective_originalyear) + item->metadata.grouping()
+          PrettyYearAlbum(effective_originalyear, item->metadata.album());
-                        + item->metadata.album();
+      item->sort_text = SortTextForNumber(effective_originalyear) +
+                        item->metadata.grouping() + item->metadata.album();
       break;
 
     case GroupBy_Year:
@@ -1050,7 +1047,8 @@ LibraryItem* LibraryModel::ItemFromSong(GroupBy type, bool signal,
       item->metadata.set_originalyear(originalyear);
       item->metadata.set_album(s.album());
       item->key = PrettyYearAlbum(effective_originalyear, s.album());
-      item->sort_text = SortTextForNumber(effective_originalyear) + s.grouping() + s.album();
+      item->sort_text =
+          SortTextForNumber(effective_originalyear) + s.grouping() + s.album();
       break;
 
     case GroupBy_Year:

src/library/librarymodel.h

@@ -195,7 +195,7 @@ signals:
   void TotalSongCountUpdatedSlot(int count);
 
   // Called after ResetAsync
-  void ResetAsyncQueryFinished();
+  void ResetAsyncQueryFinished(QFuture<LibraryModel::QueryResult> future);
 
   void AlbumArtLoaded(quint64 id, const QImage& image);
 

src/moodbar/moodbaritemdelegate.cpp

@@ -182,20 +182,14 @@ void MoodbarItemDelegate::StartLoadingColors(const QUrl& url,
                                              Data* data) {
   data->state_ = Data::State_LoadingColors;
 
-  QFutureWatcher<ColorVector>* watcher = new QFutureWatcher<ColorVector>();
-  NewClosure(watcher, SIGNAL(finished()), this,
-             SLOT(ColorsLoaded(QUrl, QFutureWatcher<ColorVector>*)), url,
-             watcher);
-
   QFuture<ColorVector> future = QtConcurrent::run(
       MoodbarRenderer::Colors, bytes, style_, qApp->palette());
-  watcher->setFuture(future);
+  NewClosure(future, this, SLOT(ColorsLoaded(QUrl, QFuture<ColorVector>)), url,
+             future);
 }
 
 void MoodbarItemDelegate::ColorsLoaded(const QUrl& url,
-                                       QFutureWatcher<ColorVector>* watcher) {
+                                       QFuture<ColorVector> future) {
-  watcher->deleteLater();
-
   Data* data = data_[url];
   if (!data) {
     return;
@@ -205,7 +199,7 @@ void MoodbarItemDelegate::ColorsLoaded(const QUrl& url,
     return;
   }
 
-  data->colors_ = watcher->result();
+  data->colors_ = future.result();
 
   // Load the image next.
   StartLoadingImage(url, data);
@@ -214,19 +208,13 @@ void MoodbarItemDelegate::ColorsLoaded(const QUrl& url,
 void MoodbarItemDelegate::StartLoadingImage(const QUrl& url, Data* data) {
   data->state_ = Data::State_LoadingImage;
 
-  QFutureWatcher<QImage>* watcher = new QFutureWatcher<QImage>();
-  NewClosure(watcher, SIGNAL(finished()), this,
-             SLOT(ImageLoaded(QUrl, QFutureWatcher<QImage>*)), url, watcher);
-
   QFuture<QImage> future = QtConcurrent::run(
       MoodbarRenderer::RenderToImage, data->colors_, data->desired_size_);
-  watcher->setFuture(future);
+  NewClosure(future, this, SLOT(ImageLoaded(QUrl, QFuture<QImage>)), url,
+             future);
 }
 
-void MoodbarItemDelegate::ImageLoaded(const QUrl& url,
+void MoodbarItemDelegate::ImageLoaded(const QUrl& url, QFuture<QImage> future) {
-                                      QFutureWatcher<QImage>* watcher) {
-  watcher->deleteLater();
-
   Data* data = data_[url];
   if (!data) {
     return;
@@ -236,7 +224,7 @@ void MoodbarItemDelegate::ImageLoaded(const QUrl& url,
     return;
   }
 
-  QImage image(watcher->result());
+  QImage image(future.result());
 
   // If the desired size changed then don't even bother converting the image
   // to a pixmap, just reload it at the new size.

src/moodbar/moodbaritemdelegate.h

@@ -21,8 +21,8 @@
 #include "moodbarrenderer.h"
 
 #include <QCache>
+#include <QFuture>
 #include <QItemDelegate>
-#include <QFutureWatcher>
 #include <QUrl>
 
 class Application;
@@ -45,8 +45,8 @@ class MoodbarItemDelegate : public QItemDelegate {
   void ReloadSettings();
 
   void DataLoaded(const QUrl& url, MoodbarPipeline* pipeline);
-  void ColorsLoaded(const QUrl& url, QFutureWatcher<ColorVector>* watcher);
+  void ColorsLoaded(const QUrl& url, QFuture<ColorVector> future);
-  void ImageLoaded(const QUrl& url, QFutureWatcher<QImage>* watcher);
+  void ImageLoaded(const QUrl& url, QFuture<QImage> future);
 
  private:
   struct Data {

src/playlist/playlist.cpp

@@ -1457,10 +1457,6 @@ void Playlist::Save() const {
                               dynamic_playlist_);
 }
 
-namespace {
-typedef QFutureWatcher<QList<PlaylistItemPtr>> PlaylistItemFutureWatcher;
-}
-
 void Playlist::Restore() {
   if (!backend_) return;
 
@@ -1470,17 +1466,12 @@ void Playlist::Restore() {
 
   QFuture<QList<PlaylistItemPtr>> future =
       QtConcurrent::run(backend_, &PlaylistBackend::GetPlaylistItems, id_);
-  PlaylistItemFutureWatcher* watcher = new PlaylistItemFutureWatcher(this);
+  NewClosure(future, this, SLOT(ItemsLoaded(QFuture<PlaylistItemList>)),
-  watcher->setFuture(future);
+             future);
-  connect(watcher, SIGNAL(finished()), SLOT(ItemsLoaded()));
 }
 
-void Playlist::ItemsLoaded() {
+void Playlist::ItemsLoaded(QFuture<PlaylistItemList> future) {
-  PlaylistItemFutureWatcher* watcher =
+  PlaylistItemList items = future.result();
-      static_cast<PlaylistItemFutureWatcher*>(sender());
-  watcher->deleteLater();
-
-  PlaylistItemList items = watcher->future().result();
 
   // backend returns empty elements for library items which it couldn't
   // match (because they got deleted); we don't need those

src/playlist/playlist.h

@@ -394,7 +394,7 @@ signals:
   void SongSaveComplete(TagReaderReply* reply,
                         const QPersistentModelIndex& index);
   void ItemReloadComplete(const QPersistentModelIndex& index);
-  void ItemsLoaded();
+  void ItemsLoaded(QFuture<PlaylistItemList> future);
   void SongInsertVetoListenerDestroyed();
 
  private:

src/playlist/playlistdelegates.cpp

@@ -20,7 +20,6 @@
 #include <QDateTime>
 #include <QDir>
 #include <QFuture>
-#include <QFutureWatcher>
 #include <QHeaderView>
 #include <QHelpEvent>
 #include <QLinearGradient>
@@ -400,19 +399,12 @@ TagCompleter::TagCompleter(LibraryBackend* backend, Playlist::Column column,
     : QCompleter(editor), editor_(editor) {
   QFuture<TagCompletionModel*> future =
       QtConcurrent::run(&InitCompletionModel, backend, column);
-  QFutureWatcher<TagCompletionModel*>* watcher =
+  NewClosure(future, this, SLOT(ModelReady(QFuture<TagCompletionModel*>)),
-      new QFutureWatcher<TagCompletionModel*>(this);
+             future);
-  watcher->setFuture(future);
-
-  connect(watcher, SIGNAL(finished()), SLOT(ModelReady()));
 }
 
-void TagCompleter::ModelReady() {
+void TagCompleter::ModelReady(QFuture<TagCompletionModel*> future) {
-  QFutureWatcher<TagCompletionModel*>* watcher =
+  TagCompletionModel* model = future.result();
-      dynamic_cast<QFutureWatcher<TagCompletionModel*>*>(sender());
-  if (!watcher) return;
-
-  TagCompletionModel* model = watcher->result();
   setModel(model);
   setCaseSensitivity(Qt::CaseInsensitive);
   editor_->setCompleter(this);
@@ -421,7 +413,6 @@ void TagCompleter::ModelReady() {
 QWidget* TagCompletionItemDelegate::createEditor(QWidget* parent,
                                                  const QStyleOptionViewItem&,
                                                  const QModelIndex&) const {
-
   QLineEdit* editor = new QLineEdit(parent);
   new TagCompleter(backend_, column_, editor);
 

src/playlist/playlistdelegates.h

@@ -159,7 +159,7 @@ class TagCompleter : public QCompleter {
                QLineEdit* editor);
 
  private slots:
-  void ModelReady();
+  void ModelReady(QFuture<TagCompletionModel*> future);
 
  private:
   QLineEdit* editor_;

src/playlist/playlistitem.h

@@ -20,6 +20,7 @@
 
 #include <memory>
 
+#include <QFuture>
 #include <QMap>
 #include <QMetaType>
 #include <QStandardItem>
@@ -97,7 +98,10 @@ class PlaylistItem : public std::enable_shared_from_this<PlaylistItem> {
  protected:
   bool should_skip_;
 
-  enum DatabaseColumn { Column_LibraryId, Column_InternetService, };
+  enum DatabaseColumn {
+    Column_LibraryId,
+    Column_InternetService,
+  };
 
   virtual QVariant DatabaseValue(DatabaseColumn) const {
     return QVariant(QVariant::String);

src/playlist/playlistmanager.cpp

@@ -33,7 +33,6 @@
 #include <QFileDialog>
 #include <QFileInfo>
 #include <QFuture>
-#include <QFutureWatcher>
 #include <QMessageBox>
 #include <QtConcurrentRun>
 #include <QtDebug>
@@ -185,21 +184,16 @@ void PlaylistManager::Save(int id, const QString& filename,
     // from the left side bar and the playlist isn't loaded.
     QFuture<QList<Song>> future = QtConcurrent::run(
         playlist_backend_, &PlaylistBackend::GetPlaylistSongs, id);
-    QFutureWatcher<SongList>* watcher = new QFutureWatcher<SongList>(this);
+    NewClosure(future, this, SLOT(ItemsLoadedForSavePlaylist(
-    watcher->setFuture(future);
+                                 QFuture<SongList>, QString, Playlist::Path)),
-
+               future, filename, path_type);
-    NewClosure(watcher, SIGNAL(finished()), this,
-               SLOT(ItemsLoadedForSavePlaylist(QFutureWatcher<SongList>*,
-                                               QString, Playlist::Path)),
-               watcher, filename);
   }
 }
 
-void PlaylistManager::ItemsLoadedForSavePlaylist(
+void PlaylistManager::ItemsLoadedForSavePlaylist(QFuture<SongList> future,
-    QFutureWatcher<SongList>* watcher, const QString& filename,
+                                                 const QString& filename,
                                                  Playlist::Path path_type) {
-  SongList song_list = watcher->future().result();
+  parser_->Save(future.result(), filename, path_type);
-  parser_->Save(song_list, filename, path_type);
 }
 
 void PlaylistManager::SaveWithUI(int id, const QString& suggested_filename) {

src/playlist/playlistmanager.h

@@ -234,7 +234,7 @@ class PlaylistManager : public PlaylistManagerInterface {
   void OneOfPlaylistsChanged();
   void UpdateSummaryText();
   void SongsDiscovered(const SongList& songs);
-  void ItemsLoadedForSavePlaylist(QFutureWatcher<SongList>* watcher,
+  void ItemsLoadedForSavePlaylist(QFuture<SongList> future,
                                   const QString& filename,
                                   Playlist::Path path_type);
 

src/smartplaylists/generatorinserter.cpp

@@ -15,18 +15,16 @@
    along with Clementine.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "generator.h"
+#include "smartplaylists/generatorinserter.h"
-#include "generatorinserter.h"
-#include "core/taskmanager.h"
-#include "playlist/playlist.h"
 
-#include <QFutureWatcher>
 #include <QtConcurrentRun>
 
-namespace smart_playlists {
+#include "core/closure.h"
+#include "core/taskmanager.h"
+#include "playlist/playlist.h"
+#include "smartplaylists/generator.h"
 
-typedef QFuture<PlaylistItemList> Future;
+namespace smart_playlists {
-typedef QFutureWatcher<PlaylistItemList> FutureWatcher;
 
 GeneratorInserter::GeneratorInserter(TaskManager* task_manager,
                                      LibraryBackend* library, QObject* parent)
@@ -57,18 +55,13 @@ void GeneratorInserter::Load(Playlist* destination, int row, bool play_now,
 
   connect(generator.get(), SIGNAL(Error(QString)), SIGNAL(Error(QString)));
 
-  Future future = QtConcurrent::run(Generate, generator, dynamic_count);
+  QFuture<PlaylistItemList> future =
-  FutureWatcher* watcher = new FutureWatcher(this);
+      QtConcurrent::run(Generate, generator, dynamic_count);
-  watcher->setFuture(future);
+  NewClosure(future, this, SLOT(Finished(QFuture<PlaylistItemList>)), future);
-
-  connect(watcher, SIGNAL(finished()), SLOT(Finished()));
 }
 
-void GeneratorInserter::Finished() {
+void GeneratorInserter::Finished(QFuture<PlaylistItemList> future) {
-  FutureWatcher* watcher = static_cast<FutureWatcher*>(sender());
+  PlaylistItemList items = future.result();
-  watcher->deleteLater();
-
-  PlaylistItemList items = watcher->result();
 
   if (items.isEmpty()) {
     if (is_dynamic_) {

src/smartplaylists/generatorinserter.h

@@ -20,8 +20,11 @@
 
 #include "generator_fwd.h"
 
+#include <QFuture>
 #include <QObject>
 
+#include "playlist/playlist.h"
+
 class LibraryBackend;
 class Playlist;
 class TaskManager;
@@ -45,7 +48,7 @@ signals:
   void PlayRequested(const QModelIndex& index);
 
  private slots:
-  void Finished();
+  void Finished(QFuture<PlaylistItemList> future);
 
  private:
   TaskManager* task_manager_;

src/smartplaylists/searchpreview.cpp

@@ -20,7 +20,6 @@
 
 #include <memory>
 
-#include <QFutureWatcher>
 #include <QtConcurrentRun>
 
 #include "querygenerator.h"
@@ -28,9 +27,6 @@
 
 namespace smart_playlists {
 
-typedef QFuture<PlaylistItemList> Future;
-typedef QFutureWatcher<PlaylistItemList> FutureWatcher;
-
 SearchPreview::SearchPreview(QWidget* parent)
     : QWidget(parent), ui_(new Ui_SmartPlaylistSearchPreview), model_(nullptr) {
   ui_->setupUi(this);
@@ -95,17 +91,12 @@ void SearchPreview::RunSearch(const Search& search) {
 
   ui_->busy_container->show();
   ui_->count_label->hide();
-  Future future = QtConcurrent::run(DoRunSearch, generator_);
+  QFuture<PlaylistItemList> future = QtConcurrent::run(DoRunSearch, generator_);
-
+  NewClosure(future, this, SLOT(SearchFinished(QFuture<PlaylistItemList>)),
-  FutureWatcher* watcher = new FutureWatcher(this);
+             future);
-  watcher->setFuture(future);
-  connect(watcher, SIGNAL(finished()), SLOT(SearchFinished()));
 }
 
-void SearchPreview::SearchFinished() {
+void SearchPreview::SearchFinished(QFuture<PlaylistItemList> future) {
-  FutureWatcher* watcher = static_cast<FutureWatcher*>(sender());
-  watcher->deleteLater();
-
   last_search_ =
       std::dynamic_pointer_cast<QueryGenerator>(generator_)->search();
   generator_.reset();
@@ -118,7 +109,7 @@ void SearchPreview::SearchFinished() {
     return;
   }
 
-  PlaylistItemList all_items = watcher->result();
+  PlaylistItemList all_items = future.result();
   PlaylistItemList displayed_items = all_items.mid(0, Generator::kDefaultLimit);
 
   model_->Clear();

src/smartplaylists/searchpreview.h

@@ -21,6 +21,7 @@
 #include "search.h"
 #include "smartplaylists/generator_fwd.h"
 
+#include <QFuture>
 #include <QWidget>
 
 class Application;
@@ -49,7 +50,7 @@ class SearchPreview : public QWidget {
   void RunSearch(const Search& search);
 
  private slots:
-  void SearchFinished();
+  void SearchFinished(QFuture<PlaylistItemList> future);
 
  private:
   Ui_SmartPlaylistSearchPreview* ui_;

src/songinfo/songinfoview.cpp

@@ -15,25 +15,24 @@
    along with Clementine.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "config.h"
+#include "songinfo/songinfoview.h"
-#include "songinfoprovider.h"
-#include "songinfoview.h"
-#include "taglyricsinfoprovider.h"
-#include "ultimatelyricsprovider.h"
-#include "ultimatelyricsreader.h"
-
-#ifdef HAVE_LIBLASTFM
-#include "lastfmtrackinfoprovider.h"
-#endif
 
 #include <QFuture>
-#include <QFutureWatcher>
 #include <QSettings>
 #include <QtConcurrentRun>
 
-const char* SongInfoView::kSettingsGroup = "SongInfo";
+#include "config.h"
+#include "core/closure.h"
+#include "songinfo/songinfoprovider.h"
+#include "songinfo/taglyricsinfoprovider.h"
+#include "songinfo/ultimatelyricsprovider.h"
+#include "songinfo/ultimatelyricsreader.h"
 
-typedef QList<SongInfoProvider*> ProviderList;
+#ifdef HAVE_LIBLASTFM
+#include "songinfo/lastfmtrackinfoprovider.h"
+#endif
+
+const char* SongInfoView::kSettingsGroup = "SongInfo";
 
 SongInfoView::SongInfoView(QWidget* parent)
     : SongInfoBase(parent), ultimate_reader_(new UltimateLyricsReader(this)) {
@@ -41,10 +40,8 @@ SongInfoView::SongInfoView(QWidget* parent)
   QFuture<ProviderList> future =
       QtConcurrent::run(ultimate_reader_.get(), &UltimateLyricsReader::Parse,
                         QString(":lyrics/ultimate_providers.xml"));
-  QFutureWatcher<ProviderList>* watcher =
+  NewClosure(future, this, SLOT(UltimateLyricsParsed(QFuture<ProviderList>)),
-      new QFutureWatcher<ProviderList>(this);
+             future);
-  watcher->setFuture(future);
-  connect(watcher, SIGNAL(finished()), SLOT(UltimateLyricsParsed()));
 
 #ifdef HAVE_LIBLASTFM
   fetcher_->AddProvider(new LastfmTrackInfoProvider);
@@ -54,15 +51,11 @@ SongInfoView::SongInfoView(QWidget* parent)
 
 SongInfoView::~SongInfoView() {}
 
-void SongInfoView::UltimateLyricsParsed() {
+void SongInfoView::UltimateLyricsParsed(QFuture<ProviderList> future) {
-  QFutureWatcher<ProviderList>* watcher =
+  for (SongInfoProvider* provider : future.result()) {
-      static_cast<QFutureWatcher<ProviderList>*>(sender());
-
-  for (SongInfoProvider* provider : watcher->result()) {
     fetcher_->AddProvider(provider);
   }
 
-  watcher->deleteLater();
   ultimate_reader_.reset();
 
   ReloadSettings();

src/songinfo/songinfoview.h

@@ -49,8 +49,9 @@ class SongInfoView : public SongInfoBase {
  private:
   SongInfoProvider* ProviderByName(const QString& name) const;
 
+  typedef QList<SongInfoProvider*> ProviderList;
  private slots:
-  void UltimateLyricsParsed();
+  void UltimateLyricsParsed(QFuture<ProviderList> future);
 
  private:
   std::unique_ptr<UltimateLyricsReader> ultimate_reader_;

src/ui/edittagdialog.cpp

@@ -15,26 +15,14 @@
    along with Clementine.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "albumcovermanager.h"
+#include "ui/edittagdialog.h"
-#include "edittagdialog.h"
-#include "trackselectiondialog.h"
 #include "ui_edittagdialog.h"
-#include "core/application.h"
+
-#include "core/logging.h"
+#include <limits>
-#include "core/tagreaderclient.h"
-#include "core/utilities.h"
-#include "covers/albumcoverloader.h"
-#include "covers/coverproviders.h"
-#include "library/library.h"
-#include "library/librarybackend.h"
-#include "playlist/playlistdelegates.h"
-#include "ui/albumcoverchoicecontroller.h"
-#include "ui/coverfromurldialog.h"
 
 #include <QDateTime>
 #include <QDir>
 #include <QFuture>
-#include <QFutureWatcher>
 #include <QLabel>
 #include <QMenu>
 #include <QMessageBox>
@@ -43,7 +31,19 @@
 #include <QtConcurrentRun>
 #include <QtDebug>
 
-#include <limits>
+#include "core/application.h"
+#include "core/logging.h"
+#include "core/tagreaderclient.h"
+#include "core/utilities.h"
+#include "covers/albumcoverloader.h"
+#include "covers/coverproviders.h"
+#include "library/librarybackend.h"
+#include "library/library.h"
+#include "playlist/playlistdelegates.h"
+#include "ui/albumcoverchoicecontroller.h"
+#include "ui/albumcovermanager.h"
+#include "ui/coverfromurldialog.h"
+#include "ui/trackselectiondialog.h"
 
 const char* EditTagDialog::kHintText =
     QT_TR_NOOP("(different across multiple songs)");
@@ -158,11 +158,9 @@ EditTagDialog::EditTagDialog(Application* app, QWidget* parent)
   ui_->art->setAcceptDrops(true);
 
   // Add the next/previous buttons
-  previous_button_ =
+  previous_button_ = new QPushButton(
-      new QPushButton(IconLoader::Load("go-previous", IconLoader::Base), 
+      IconLoader::Load("go-previous", IconLoader::Base), tr("Previous"), this);
-                      tr("Previous"), this);
+  next_button_ = new QPushButton(IconLoader::Load("go-next", IconLoader::Base),
-  next_button_ = 
-      new QPushButton(IconLoader::Load("go-next", IconLoader::Base), 
                                  tr("Next"), this);
   ui_->button_box->addButton(previous_button_, QDialogButtonBox::ResetRole);
   ui_->button_box->addButton(next_button_, QDialogButtonBox::ResetRole);
@@ -251,20 +249,15 @@ void EditTagDialog::SetSongs(const SongList& s, const PlaylistItemList& items) {
   // Reload tags in the background
   QFuture<QList<Data>> future =
       QtConcurrent::run(this, &EditTagDialog::LoadData, s);
-  QFutureWatcher<QList<Data>>* watcher = new QFutureWatcher<QList<Data>>(this);
+  NewClosure(future, this,
-  watcher->setFuture(future);
+             SLOT(SetSongsFinished(QFuture<QList<EditTagDialog::Data>>)),
-  connect(watcher, SIGNAL(finished()), SLOT(SetSongsFinished()));
+             future);
 }
 
-void EditTagDialog::SetSongsFinished() {
+void EditTagDialog::SetSongsFinished(QFuture<QList<Data>> future) {
-  QFutureWatcher<QList<Data>>* watcher =
-      dynamic_cast<QFutureWatcher<QList<Data>>*>(sender());
-  if (!watcher) return;
-  watcher->deleteLater();
-
   if (!SetLoading(QString())) return;
 
-  data_ = watcher->result();
+  data_ = future.result();
   if (data_.count() == 0) {
     // If there were no valid songs, disable everything
     ui_->song_list->setEnabled(false);
@@ -708,16 +701,10 @@ void EditTagDialog::accept() {
   // Save tags in the background
   QFuture<void> future =
       QtConcurrent::run(this, &EditTagDialog::SaveData, data_);
-  QFutureWatcher<void>* watcher = new QFutureWatcher<void>(this);
+  NewClosure(future, this, SLOT(AcceptFinished()));
-  watcher->setFuture(future);
-  connect(watcher, SIGNAL(finished()), SLOT(AcceptFinished()));
 }
 
 void EditTagDialog::AcceptFinished() {
-  QFutureWatcher<void>* watcher = dynamic_cast<QFutureWatcher<void>*>(sender());
-  if (!watcher) return;
-  watcher->deleteLater();
-
   if (!SetLoading(QString())) return;
 
   QDialog::accept();

src/ui/edittagdialog.h

@@ -64,8 +64,26 @@ signals:
   void showEvent(QShowEvent*);
   void hideEvent(QHideEvent*);
 
+ private:
+  struct Data {
+    Data(const Song& song = Song()) : original_(song), current_(song) {}
+
+    static QVariant value(const Song& song, const QString& id);
+    QVariant original_value(const QString& id) const {
+      return value(original_, id);
+    }
+    QVariant current_value(const QString& id) const {
+      return value(current_, id);
+    }
+
+    void set_value(const QString& id, const QVariant& value);
+
+    Song original_;
+    Song current_;
+  };
+
  private slots:
-  void SetSongsFinished();
+  void SetSongsFinished(QFuture<QList<EditTagDialog::Data>> future);
   void AcceptFinished();
 
   void SelectionChanged();
@@ -90,23 +108,6 @@ signals:
   void NextSong();
 
  private:
-  struct Data {
-    Data(const Song& song = Song()) : original_(song), current_(song) {}
-
-    static QVariant value(const Song& song, const QString& id);
-    QVariant original_value(const QString& id) const {
-      return value(original_, id);
-    }
-    QVariant current_value(const QString& id) const {
-      return value(current_, id);
-    }
-
-    void set_value(const QString& id, const QVariant& value);
-
-    Song original_;
-    Song current_;
-  };
-
   struct FieldData {
     FieldData(QLabel* label = nullptr, QWidget* editor = nullptr,
               const QString& id = QString())

src/ui/organisedialog.cpp

@@ -22,7 +22,6 @@
 
 #include <QDir>
 #include <QFileInfo>
-#include <QFutureWatcher>
 #include <QHash>
 #include <QMenu>
 #include <QPushButton>
@@ -53,7 +52,8 @@ OrganiseDialog::OrganiseDialog(TaskManager* task_manager, QWidget* parent)
   connect(ui_->button_box->button(QDialogButtonBox::Reset), SIGNAL(clicked()),
           SLOT(Reset()));
 
-  ui_->aftercopying->setItemIcon(1, IconLoader::Load("edit-delete", IconLoader::Base));
+  ui_->aftercopying->setItemIcon(
+      1, IconLoader::Load("edit-delete", IconLoader::Base));
 
   // Valid tags
   QMap<QString, QString> tags;
@@ -155,12 +155,7 @@ bool OrganiseDialog::SetUrls(const QList<QUrl>& urls) {
 bool OrganiseDialog::SetFilenames(const QStringList& filenames) {
   songs_future_ =
       QtConcurrent::run(this, &OrganiseDialog::LoadSongsBlocking, filenames);
-  QFutureWatcher<SongList>* watcher = new QFutureWatcher<SongList>(this);
+  NewClosure(songs_future_, [=]() { SetSongs(songs_future_.result()); });
-  watcher->setFuture(songs_future_);
-  NewClosure(watcher, SIGNAL(finished()), [=]() {
-    SetSongs(songs_future_.result());
-    watcher->deleteLater();
-  });
 
   SetLoadingSongs(true);
   return true;

src/ui/organisedialog.h

@@ -21,6 +21,7 @@
 #include <memory>
 
 #include <QDialog>
+#include <QFuture>
 #include <QMap>
 #include <QUrl>
 

src/ui/trackselectiondialog.cpp

@@ -15,13 +15,10 @@
    along with Clementine.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "iconloader.h"
+#include "ui/trackselectiondialog.h"
-#include "trackselectiondialog.h"
 #include "ui_trackselectiondialog.h"
-#include "core/tagreaderclient.h"
 
 #include <QFileInfo>
-#include <QFutureWatcher>
 #include <QPushButton>
 #include <QShortcut>
 #include <QTreeWidget>
@@ -29,6 +26,9 @@
 #include <QtConcurrentRun>
 #include <QtDebug>
 
+#include "core/tagreaderclient.h"
+#include "ui/iconloader.h"
+
 TrackSelectionDialog::TrackSelectionDialog(QWidget* parent)
     : QDialog(parent), ui_(new Ui_TrackSelectionDialog), save_on_close_(false) {
   // Setup dialog window
@@ -43,9 +43,8 @@ TrackSelectionDialog::TrackSelectionDialog(QWidget* parent)
   SetLoading(QString());
 
   // Add the next/previous buttons
-  previous_button_ =
+  previous_button_ = new QPushButton(
-      new QPushButton(IconLoader::Load("go-previous", IconLoader::Base), 
+      IconLoader::Load("go-previous", IconLoader::Base), tr("Previous"), this);
-                      tr("Previous"), this);
   next_button_ = new QPushButton(IconLoader::Load("go-next", IconLoader::Base),
                                  tr("Next"), this);
   ui_->button_box->addButton(previous_button_, QDialogButtonBox::ResetRole);
@@ -258,10 +257,7 @@ void TrackSelectionDialog::accept() {
     // Save tags in the background
     QFuture<void> future =
         QtConcurrent::run(&TrackSelectionDialog::SaveData, data_);
-    QFutureWatcher<void>* watcher = new QFutureWatcher<void>(this);
+    NewClosure(future, this, SLOT(AcceptFinished()));
-    watcher->setFuture(future);
-    connect(watcher, SIGNAL(finished()), SLOT(AcceptFinished()));
-
     return;
   }
 
@@ -278,10 +274,6 @@ void TrackSelectionDialog::accept() {
 }
 
 void TrackSelectionDialog::AcceptFinished() {
-  QFutureWatcher<void>* watcher = dynamic_cast<QFutureWatcher<void>*>(sender());
-  if (!watcher) return;
-  watcher->deleteLater();
-
   SetLoading(QString());
   QDialog::accept();
 }