Add explicit

src/collection/collection.h

@@ -43,7 +43,7 @@ class SCollection : public QObject {
   Q_OBJECT
 
  public:
-  SCollection(Application *app, QObject *parent);
+  explicit SCollection(Application *app, QObject *parent);
   ~SCollection();
 
   static const char *kSongsTable;

src/collection/collectionbackend.h

@@ -45,7 +45,7 @@ class CollectionBackendInterface : public QObject {
   Q_OBJECT
 
  public:
-  CollectionBackendInterface(QObject *parent = nullptr) : QObject(parent) {}
+  explicit CollectionBackendInterface(QObject *parent = nullptr) : QObject(parent) {}
   virtual ~CollectionBackendInterface() {}
 
   struct Album {

src/collection/collectiondirectorymodel.h

@@ -42,7 +42,7 @@ class CollectionDirectoryModel : public QStandardItemModel {
   Q_OBJECT
 
  public:
-  CollectionDirectoryModel(CollectionBackend* backend, QObject *parent = nullptr);
+  explicit CollectionDirectoryModel(CollectionBackend* backend, QObject *parent = nullptr);
   ~CollectionDirectoryModel();
 
   // To be called by GUIs

src/collection/collectionfilterwidget.h

@@ -48,7 +48,7 @@ class CollectionFilterWidget : public QWidget {
   Q_OBJECT
 
  public:
-  CollectionFilterWidget(QWidget *parent = nullptr);
+  explicit CollectionFilterWidget(QWidget *parent = nullptr);
   ~CollectionFilterWidget();
 
   static const int kFilterDelay = 500;  // msec

src/collection/collectionitem.h

@@ -37,12 +37,12 @@ class CollectionItem : public SimpleTreeItem<CollectionItem> {
     Type_LoadingIndicator,
   };
 
-  CollectionItem(SimpleTreeModel<CollectionItem> *model)
+  explicit CollectionItem(SimpleTreeModel<CollectionItem> *model)
       : SimpleTreeItem<CollectionItem>(Type_Root, model),
         container_level(-1),
         compilation_artist_node_(nullptr) {}
 
-  CollectionItem(Type type, CollectionItem *parent = nullptr)
+  explicit CollectionItem(Type type, CollectionItem *parent = nullptr)
       : SimpleTreeItem<CollectionItem>(type, parent),
         container_level(-1),
         compilation_artist_node_(nullptr) {}

src/collection/collectionitemdelegate.h

@@ -36,7 +36,7 @@ class CollectionItemDelegate : public QStyledItemDelegate {
   Q_OBJECT
 
  public:
-  CollectionItemDelegate(QObject *parent);
+  explicit CollectionItemDelegate(QObject *parent);
   void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const;
 
  public slots:

src/collection/collectionmodel.h

@@ -62,7 +62,7 @@ class CollectionModel : public SimpleTreeModel<CollectionItem> {
   Q_ENUMS(GroupBy)
 
  public:
-  CollectionModel(CollectionBackend *backend, Application *app, QObject *parent = nullptr);
+  explicit CollectionModel(CollectionBackend *backend, Application *app, QObject *parent = nullptr);
   ~CollectionModel();
 
   static const char *kSavedGroupingsSettingsGroup;

src/collection/collectionplaylistitem.h

@@ -33,8 +33,8 @@ class SqlRow;
 
 class CollectionPlaylistItem : public PlaylistItem {
  public:
-  CollectionPlaylistItem();
+  explicit CollectionPlaylistItem();
-  CollectionPlaylistItem(const Song &song);
+  explicit CollectionPlaylistItem(const Song &song);
 
   bool InitFromQuery(const SqlRow &query);
   void Reload();

src/collection/collectionquery.h

@@ -72,7 +72,7 @@ struct QueryOptions {
 
 class CollectionQuery {
  public:
-  CollectionQuery(const QueryOptions &options = QueryOptions());
+  explicit CollectionQuery(const QueryOptions &options = QueryOptions());
 
   // Sets contents of SELECT clause on the query (list of columns to get).
   void SetColumnSpec(const QString &spec) { column_spec_ = spec; }

src/collection/collectionview.h

@@ -53,7 +53,7 @@ class CollectionView : public AutoExpandingTreeView {
   Q_OBJECT
 
  public:
-  CollectionView(QWidget *parent = nullptr);
+  explicit CollectionView(QWidget *parent = nullptr);
   ~CollectionView();
 
   // Returns Songs currently selected in the collection view.

src/collection/collectionviewcontainer.h

@@ -34,7 +34,7 @@ class CollectionViewContainer : public QWidget {
   Q_OBJECT
 
  public:
-  CollectionViewContainer(QWidget *parent = nullptr);
+  explicit CollectionViewContainer(QWidget *parent = nullptr);
   ~CollectionViewContainer();
 
   CollectionFilterWidget *filter() const;

src/collection/collectionwatcher.h

@@ -48,7 +48,7 @@ class CollectionWatcher : public QObject {
   Q_OBJECT
 
  public:
-  CollectionWatcher(Song::Source source, QObject *parent = nullptr);
+  explicit CollectionWatcher(Song::Source source, QObject *parent = nullptr);
 
   void set_backend(CollectionBackend *backend) { backend_ = backend; }
   void set_task_manager(TaskManager *task_manager) { task_manager_ = task_manager; }

src/collection/groupbydialog.h

@@ -40,7 +40,7 @@ class GroupByDialog : public QDialog {
   Q_OBJECT
 
  public:
-  GroupByDialog(QWidget *parent = nullptr);
+  explicit GroupByDialog(QWidget *parent = nullptr);
   ~GroupByDialog();
 
  public slots:

src/collection/savedgroupingmanager.h

@@ -39,7 +39,7 @@ class SavedGroupingManager : public QDialog {
   Q_OBJECT
 
  public:
-  SavedGroupingManager(QWidget *parent = nullptr);
+  explicit SavedGroupingManager(QWidget *parent = nullptr);
   ~SavedGroupingManager();
 
   void UpdateModel();

src/context/contextalbum.h

@@ -44,7 +44,7 @@ class ContextAlbum : public QWidget {
   Q_OBJECT
 
  public:
-  ContextAlbum(QWidget *parent = nullptr);
+  explicit ContextAlbum(QWidget *parent = nullptr);
 
   void Init(AlbumCoverChoiceController *album_cover_choice_controller);
   void SetImage(QImage image = QImage());

src/context/contextalbumsmodel.h

@@ -56,7 +56,7 @@ class ContextAlbumsModel : public SimpleTreeModel<CollectionItem> {
   Q_OBJECT
 
  public:
-  ContextAlbumsModel(CollectionBackend *backend, Application *app, QObject *parent = nullptr);
+  explicit ContextAlbumsModel(CollectionBackend *backend, Application *app, QObject *parent = nullptr);
   ~ContextAlbumsModel();
 
   static const int kPrettyCoverSize;

src/context/contextalbumsview.h

@@ -54,7 +54,7 @@ class ContextItemDelegate : public QStyledItemDelegate {
   Q_OBJECT
 
  public:
-  ContextItemDelegate(QObject *parent);
+  explicit ContextItemDelegate(QObject *parent);
 
  public slots:
   bool helpEvent(QHelpEvent *event, QAbstractItemView *view, const QStyleOptionViewItem &option, const QModelIndex &index);

src/context/contextview.h

@@ -54,7 +54,7 @@ class ContextView : public QWidget {
   Q_OBJECT
 
  public:
-  ContextView(QWidget *parent = nullptr);
+  explicit ContextView(QWidget *parent = nullptr);
 
   void Init(Application *app, CollectionView *collectionview, AlbumCoverChoiceController *album_cover_choice_controller);
 

src/core/database.h

@@ -42,7 +42,7 @@ class Database : public QObject {
   Q_OBJECT
 
  public:
-  Database(Application *app, QObject *parent = nullptr, const QString &database_name = QString());
+  explicit Database(Application *app, QObject *parent = nullptr, const QString &database_name = QString());
   ~Database();
 
   struct AttachedDatabase {

src/core/dbusscreensaver.h

@@ -30,7 +30,7 @@
 
 class DBusScreensaver : public Screensaver {
  public:
-  DBusScreensaver(const QString &service, const QString &path, const QString &interface);
+  explicit DBusScreensaver(const QString &service, const QString &path, const QString &interface);
 
   void Inhibit();
   void Uninhibit();

src/core/deletefiles.h

@@ -38,7 +38,7 @@ class DeleteFiles : public QObject {
   Q_OBJECT
 
  public:
-  DeleteFiles(TaskManager *task_manager, std::shared_ptr<MusicStorage> storage);
+  explicit DeleteFiles(TaskManager *task_manager, std::shared_ptr<MusicStorage> storage);
   ~DeleteFiles();
 
   static const int kBatchSize;

src/core/iconloader.h

@@ -28,7 +28,7 @@ class IconLoader {
   static void Init();
   static QIcon Load(const QString &name, const int size = 0);
  private:
-  IconLoader() {}
+  explicit IconLoader() {}
   static bool system_icons_;
   static bool custom_icons_;
 };

src/core/iconmapper.h

@@ -25,7 +25,7 @@
 namespace IconMapper {
 
 struct IconProperties {
-  IconProperties() : min_size(0), max_size(0) {}
+  explicit IconProperties() : min_size(0), max_size(0) {}
   IconProperties(const QStringList &_names, const int _min_size, const int _max_size) : names(_names), min_size(_min_size), max_size(_max_size) {}
   QStringList names;
   int min_size;

src/core/macscreensaver.h

@@ -29,7 +29,7 @@
 
 class MacScreensaver : public Screensaver {
  public:
-  MacScreensaver();
+  explicit MacScreensaver();
 
   void Inhibit();
   void Uninhibit();

src/core/macsystemtrayicon.h

@@ -38,7 +38,7 @@ class MacSystemTrayIcon : public SystemTrayIcon {
   Q_OBJECT
 
  public:
-  MacSystemTrayIcon(QObject *parent = nullptr);
+  explicit MacSystemTrayIcon(QObject *parent = nullptr);
   ~MacSystemTrayIcon();
 
   void SetupMenu(QAction *previous, QAction *play, QAction *stop, QAction *stop_after, QAction *next, QAction *mute, QAction *love, QAction *quit);

src/core/mainwindow.h

@@ -100,7 +100,7 @@ class MainWindow : public QMainWindow, public PlatformInterface {
   Q_OBJECT
 
  public:
-  MainWindow(Application *app, SystemTrayIcon *tray_icon, OSD *osd, const CommandlineOptions& options, QWidget *parent = nullptr);
+  explicit MainWindow(Application *app, SystemTrayIcon *tray_icon, OSD *osd, const CommandlineOptions& options, QWidget *parent = nullptr);
   ~MainWindow();
 
   static const char *kSettingsGroup;

src/core/mpris2.h

@@ -78,7 +78,7 @@ class Mpris2 : public QObject {
   Q_OBJECT
 
  public:
-  Mpris2(Application *app, QObject *parent = nullptr);
+  explicit Mpris2(Application *app, QObject *parent = nullptr);
 
   // org.mpris.MediaPlayer2 MPRIS 2.0 Root interface
   Q_PROPERTY(bool CanQuit READ CanQuit)

src/core/multisortfilterproxy.h

@@ -32,7 +32,7 @@ class QObject;
 
 class MultiSortFilterProxy : public QSortFilterProxyModel {
  public:
-  MultiSortFilterProxy(QObject *parent = nullptr);
+  explicit MultiSortFilterProxy(QObject *parent = nullptr);
 
   void AddSortSpec(int role, Qt::SortOrder order = Qt::AscendingOrder);
 

src/core/musicstorage.h

@@ -36,7 +36,7 @@
 
 class MusicStorage {
  public:
-  MusicStorage();
+  explicit MusicStorage();
   virtual ~MusicStorage() {}
 
   enum Role {

src/core/networkproxyfactory.h

@@ -44,7 +44,7 @@ class NetworkProxyFactory : public QNetworkProxyFactory {
   QList<QNetworkProxy> queryProxy(const QNetworkProxyQuery &query);
 
  private:
-  NetworkProxyFactory();
+  explicit NetworkProxyFactory();
 
   static NetworkProxyFactory *sInstance;
 

src/core/scopedtransaction.h

@@ -31,7 +31,7 @@ class QSqlDatabase;
 // Rolls back the transaction if the object goes out of scope before Commit() is called.
 class ScopedTransaction : boost::noncopyable {
  public:
-  ScopedTransaction(QSqlDatabase *db);
+  explicit ScopedTransaction(QSqlDatabase *db);
   ~ScopedTransaction();
 
   void Commit();

src/core/settingsprovider.h

@@ -29,7 +29,7 @@
 
 class SettingsProvider {
  public:
-  SettingsProvider();
+  explicit SettingsProvider();
   virtual ~SettingsProvider() {}
 
   virtual void set_group(const char *group) = 0;

src/core/simpletreeitem.h

@@ -32,8 +32,8 @@
 template <typename T>
 class SimpleTreeItem {
  public:
-  SimpleTreeItem(int _type, SimpleTreeModel<T>* _model);  // For the root item
+  explicit SimpleTreeItem(int _type, SimpleTreeModel<T>* _model);  // For the root item
-  SimpleTreeItem(int _type, const QString& _key, T* _parent = nullptr);
+  explicit SimpleTreeItem(int _type, const QString& _key, T* _parent = nullptr);
   explicit SimpleTreeItem(int _type, T* _parent = nullptr);
   virtual ~SimpleTreeItem();
 

src/core/song.cpp

@@ -156,7 +156,7 @@ const QStringList Song::kArticles = QStringList() << "the " << "a " << "an ";
 
 struct Song::Private : public QSharedData {
 
-  Private(Source source = Source_Unknown);
+  explicit Private(Source source = Source_Unknown);
 
   bool valid_;
   int id_;

src/core/song.h

@@ -103,7 +103,7 @@ class Song {
     FileType_Stream = 91,
   };
 
-  Song(Song::Source source = Song::Source_Unknown);
+  explicit Song(Song::Source source = Song::Source_Unknown);
   Song(const Song &other);
   ~Song();
 

src/core/standarditemiconloader.h

@@ -43,7 +43,7 @@ class StandardItemIconLoader : public QObject {
   Q_OBJECT
 
  public:
-  StandardItemIconLoader(AlbumCoverLoader *cover_loader, QObject *parent = nullptr);
+  explicit StandardItemIconLoader(AlbumCoverLoader *cover_loader, QObject *parent = nullptr);
 
   AlbumCoverLoaderOptions *options() { return &cover_options_; }
 

src/core/systemtrayicon.h

@@ -36,7 +36,7 @@ class SystemTrayIcon : public QObject {
   Q_OBJECT
 
  public:
-  SystemTrayIcon(QObject *parent = nullptr);
+  explicit SystemTrayIcon(QObject *parent = nullptr);
 
   // Called once to create the icon's context menu
   virtual void SetupMenu(QAction *previous, QAction *play, QAction *stop, QAction *stop_after, QAction *next, QAction *mute, QAction *love, QAction *quit) = 0;

src/core/thread.h

@@ -29,8 +29,7 @@ class QObject;
 // Improve QThread by adding a SetIoPriority function
 class Thread : public QThread {
  public:
-  Thread(QObject* parent = nullptr)
+  explicit Thread(QObject* parent = nullptr) : QThread(parent), io_priority_(Utilities::IOPRIO_CLASS_NONE) {}
-      : QThread(parent), io_priority_(Utilities::IOPRIO_CLASS_NONE) {}
 
   void SetIoPriority(Utilities::IoPriority priority) {
     io_priority_ = priority;

src/core/translations.h

@@ -27,7 +27,7 @@ class QTranslator;
 
 class Translations : public QObject {
  public:
-  Translations();
+  explicit Translations();
   ~Translations();
   void LoadTranslation(const QString &prefix, const QString &path, const QString &language);
 

src/core/windows7thumbbar.h

@@ -38,7 +38,7 @@ class Windows7ThumbBar : public QObject {
 
 public:
   // Creates a list of buttons in the taskbar icon for this window.  Does nothing and is safe to use on other operating systems too.
-  Windows7ThumbBar(QWidget *widget = 0);
+  explicit Windows7ThumbBar(QWidget *widget = 0);
 
   static const int kIconSize;
   static const int kMaxButtonCount;

src/covermanager/albumcoverchoicecontroller.h

@@ -57,7 +57,7 @@ class AlbumCoverChoiceController : public QWidget {
   static const char *kSaveImageFileFilter;
   static const char *kAllFilesFilter;
 
-  AlbumCoverChoiceController(QWidget *parent = nullptr);
+  explicit AlbumCoverChoiceController(QWidget *parent = nullptr);
   ~AlbumCoverChoiceController();
 
   void Init(Application *app);

src/covermanager/albumcoverexport.h

@@ -35,7 +35,7 @@ class AlbumCoverExport : public QDialog {
   Q_OBJECT
 
  public:
-  AlbumCoverExport(QWidget *parent = nullptr);
+  explicit AlbumCoverExport(QWidget *parent = nullptr);
   ~AlbumCoverExport();
 
   enum OverwriteMode {

src/covermanager/albumcoverfetcher.h

@@ -42,7 +42,7 @@ struct CoverSearchStatistics;
 
 // This class represents a single search-for-cover request. It identifies and describes the request.
 struct CoverSearchRequest {
-  CoverSearchRequest() : id(-1), search(false), fetchall(false) {}
+  explicit CoverSearchRequest() : id(-1), search(false), fetchall(false) {}
 
   // An unique (for one AlbumCoverFetcher) request identifier
   quint64 id;
@@ -60,7 +60,7 @@ struct CoverSearchRequest {
 
 // This structure represents a single result of some album's cover search request.
 struct CoverSearchResult {
-  CoverSearchResult() : score(0.0) {}
+  explicit CoverSearchResult() : score(0.0) {}
 
   // Used for grouping in the user interface.
   QString provider;
@@ -87,7 +87,7 @@ class AlbumCoverFetcher : public QObject {
   Q_OBJECT
 
  public:
-  AlbumCoverFetcher(CoverProviders *cover_providers, QObject *parent = nullptr, QNetworkAccessManager *network = 0);
+  explicit AlbumCoverFetcher(CoverProviders *cover_providers, QObject *parent = nullptr, QNetworkAccessManager *network = 0);
   virtual ~AlbumCoverFetcher() {}
 
   static const int kMaxConcurrentRequests;

src/covermanager/albumcoverfetchersearch.h

@@ -47,7 +47,7 @@ class AlbumCoverFetcherSearch : public QObject {
   Q_OBJECT
 
  public:
-  AlbumCoverFetcherSearch(const CoverSearchRequest &request, QNetworkAccessManager *network, QObject *parent);
+  explicit AlbumCoverFetcherSearch(const CoverSearchRequest &request, QNetworkAccessManager *network, QObject *parent);
 
   void Start(CoverProviders *cover_providers);
 

src/covermanager/albumcoverloader.h

@@ -84,7 +84,7 @@ class AlbumCoverLoader : public QObject {
   };
 
   struct Task {
-    Task() : redirects(0) {}
+    explicit Task() : redirects(0) {}
 
     AlbumCoverLoaderOptions options;
 
@@ -98,7 +98,7 @@ class AlbumCoverLoader : public QObject {
   };
 
   struct TryLoadResult {
-    TryLoadResult(bool async, bool success, const QUrl &_cover_url, const QImage &_image) : started_async(async), loaded_success(success), cover_url(_cover_url), image(_image) {}
+    explicit TryLoadResult(bool async, bool success, const QUrl &_cover_url, const QImage &_image) : started_async(async), loaded_success(success), cover_url(_cover_url), image(_image) {}
 
     bool started_async;
     bool loaded_success;

src/covermanager/albumcoverloaderoptions.h

@@ -26,7 +26,7 @@
 #include <QImage>
 
 struct AlbumCoverLoaderOptions {
-  AlbumCoverLoaderOptions()
+  explicit AlbumCoverLoaderOptions()
       : desired_height_(120),
         scale_output_image_(true),
         pad_output_image_(true) {}

src/covermanager/albumcovermanagerlist.h

@@ -36,8 +36,9 @@ class AlbumCoverManager;
 
 class AlbumCoverManagerList : public QListWidget {
   Q_OBJECT
+
  public:
-  AlbumCoverManagerList(QWidget *parent = nullptr);
+  explicit AlbumCoverManagerList(QWidget *parent = nullptr);
 
   void set_cover_manager(AlbumCoverManager *manager) { manager_ = manager; }
 

src/covermanager/albumcoversearcher.h

@@ -57,7 +57,7 @@ public:
   static const int kBorderAlpha;
   static const int kBackgroundAlpha;
 
-  SizeOverlayDelegate(QObject *parent = nullptr);
+  explicit SizeOverlayDelegate(QObject *parent = nullptr);
 
   void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const;
 };
@@ -67,7 +67,7 @@ class AlbumCoverSearcher : public QDialog {
   Q_OBJECT
 
  public:
-  AlbumCoverSearcher(const QIcon &no_cover_icon, Application *app, QWidget *parent);
+  explicit AlbumCoverSearcher(const QIcon &no_cover_icon, Application *app, QWidget *parent);
   ~AlbumCoverSearcher();
 
   enum Role {

src/covermanager/coverexportrunnable.h

@@ -34,7 +34,7 @@ class CoverExportRunnable : public QObject, public QRunnable {
   Q_OBJECT
 
  public:
-  CoverExportRunnable(const AlbumCoverExport::DialogResult &dialog_result, const Song &song);
+  explicit CoverExportRunnable(const AlbumCoverExport::DialogResult &dialog_result, const Song &song);
   virtual ~CoverExportRunnable() {}
 
   void run();

src/covermanager/coverfromurldialog.h

@@ -38,7 +38,7 @@ class CoverFromURLDialog : public QDialog {
   Q_OBJECT
 
  public:
-  CoverFromURLDialog(QWidget *parent = nullptr);
+  explicit CoverFromURLDialog(QWidget *parent = nullptr);
   ~CoverFromURLDialog();
 
   // Opens the dialog. This returns an image found at the URL chosen by user or null image if the dialog got rejected.

src/covermanager/coversearchstatistics.h

@@ -30,7 +30,7 @@
 
 struct CoverSearchStatistics {
 
-  CoverSearchStatistics();
+  explicit CoverSearchStatistics();
 
   CoverSearchStatistics& operator +=(const CoverSearchStatistics &other);
 

src/covermanager/discogscoverprovider.h

@@ -42,7 +42,7 @@ class Application;
 
 // This struct represents a single search-for-cover request. It identifies and describes the request.
 struct DiscogsCoverSearchContext {
-  DiscogsCoverSearchContext() : id(-1), r_count(0) {}
+  explicit DiscogsCoverSearchContext() : id(-1), r_count(0) {}
 
   // The unique request identifier
   int id;
@@ -58,7 +58,7 @@ Q_DECLARE_METATYPE(DiscogsCoverSearchContext)
 
 // This struct represents a single release request. It identifies and describes the request.
 struct DiscogsCoverReleaseContext {
-  DiscogsCoverReleaseContext() : id(-1) {}
+  explicit DiscogsCoverReleaseContext() : id(-1) {}
 
   int id;			// The unique request identifier
   int s_id;			// The search request identifier

src/device/afcfile.h

@@ -17,7 +17,7 @@ class AfcFile : public QIODevice {
   Q_OBJECT
 
  public:
-  AfcFile(iMobileDeviceConnection* connection, const QString &path, QObject *parent = 0);
+  explicit AfcFile(iMobileDeviceConnection* connection, const QString &path, QObject *parent = 0);
   ~AfcFile();
 
   // QIODevice

src/device/afctransfer.h

@@ -39,7 +39,7 @@ class AfcTransfer : public QObject {
   Q_OBJECT
 
  public:
-  AfcTransfer(const QString &uuid, const QString &local_destination, TaskManager *task_manager, std::shared_ptr<ConnectedDevice> device);
+  explicit AfcTransfer(const QString &uuid, const QString &local_destination, TaskManager *task_manager, std::shared_ptr<ConnectedDevice> device);
   ~AfcTransfer();
 
   bool CopyToDevice(iMobileDeviceConnection *connection);

src/device/cddalister.cpp

@@ -107,7 +107,7 @@ bool CddaLister::Init() {
   cdio_init();
 #ifdef Q_OS_MACOS
   if (!cdio_have_driver(DRIVER_OSX)) {
-    qLog(Error) << "libcdio was compiled without support for OS X!";
+    qLog(Error) << "libcdio was compiled without support for macOS!";
   }
 #endif
   char** devices = cdio_get_devices(DRIVER_DEVICE);

src/device/cddalister.h

@@ -37,7 +37,7 @@ class CddaLister : public DeviceLister {
   Q_OBJECT
 
  public:
-  CddaLister() {}
+  explicit CddaLister() {}
 
   QStringList DeviceUniqueIDs();
   QVariantList DeviceIcons(const QString &id);

src/device/connecteddevice.h

@@ -43,7 +43,7 @@ class ConnectedDevice : public QObject, public virtual MusicStorage, public std:
   Q_OBJECT
 
  public:
-  ConnectedDevice(const QUrl &url, DeviceLister *lister, const QString &unique_id, DeviceManager *manager, Application *app, int database_id, bool first_time);
+  explicit ConnectedDevice(const QUrl &url, DeviceLister *lister, const QString &unique_id, DeviceManager *manager, Application *app, int database_id, bool first_time);
   ~ConnectedDevice();
 
   virtual bool Init() = 0;

src/device/deviceinfo.h

@@ -60,7 +60,7 @@ class DeviceInfo : public SimpleTreeItem<DeviceInfo> {
     Type_Device,
   };
 
-  DeviceInfo(SimpleTreeModel<DeviceInfo> *model)
+  explicit DeviceInfo(SimpleTreeModel<DeviceInfo> *model)
       : SimpleTreeItem<DeviceInfo>(Type_Root, model),
         database_id_(-1),
         size_(0),
@@ -70,7 +70,7 @@ class DeviceInfo : public SimpleTreeItem<DeviceInfo> {
         unmount_(false),
         forget_(false) {}
 
-  DeviceInfo(Type type, DeviceInfo *parent = nullptr)
+  explicit DeviceInfo(Type type, DeviceInfo *parent = nullptr)
       : SimpleTreeItem<DeviceInfo>(type, parent),
         database_id_(-1),
         size_(0),
@@ -83,7 +83,7 @@ class DeviceInfo : public SimpleTreeItem<DeviceInfo> {
   // A device can be discovered in different ways (udisks2, gio, etc.)
   // Sometimes the same device is discovered more than once.  In this case the device will have multiple "backends".
   struct Backend {
-    Backend(DeviceLister *lister = nullptr, const QString &id = QString())
+    explicit Backend(DeviceLister *lister = nullptr, const QString &id = QString())
         :
         lister_(lister),
         unique_id_(id)

src/device/devicemanager.h

@@ -58,7 +58,7 @@ class DeviceManager : public SimpleTreeModel<DeviceInfo> {
   Q_OBJECT
 
  public:
-  DeviceManager(Application *app, QObject *parent = nullptr);
+  explicit DeviceManager(Application *app, QObject *parent = nullptr);
   ~DeviceManager();
 
   enum Role {

src/device/deviceproperties.h

@@ -42,7 +42,7 @@ class DeviceProperties : public QDialog {
   Q_OBJECT
 
  public:
-  DeviceProperties(QWidget *parent = nullptr);
+  explicit DeviceProperties(QWidget *parent = nullptr);
   ~DeviceProperties();
 
   void SetDeviceManager(DeviceManager *manager);

src/device/devicestatefiltermodel.h

@@ -36,7 +36,7 @@ class DeviceStateFilterModel : public QSortFilterProxyModel {
   Q_OBJECT
 
  public:
-  DeviceStateFilterModel(QObject *parent, DeviceManager::State state = DeviceManager::State_Remembered);
+  explicit DeviceStateFilterModel(QObject *parent, DeviceManager::State state = DeviceManager::State_Remembered);
 
   void setSourceModel(QAbstractItemModel *sourceModel);
 

src/device/deviceview.h

@@ -53,7 +53,7 @@ class DeviceItemDelegate : public CollectionItemDelegate {
   Q_OBJECT
 
  public:
-  DeviceItemDelegate(QObject *parent);
+  explicit DeviceItemDelegate(QObject *parent);
 
   static const int kIconPadding;
 
@@ -65,7 +65,7 @@ class DeviceView : public AutoExpandingTreeView {
   Q_OBJECT
 
  public:
-  DeviceView(QWidget *parent = nullptr);
+  explicit DeviceView(QWidget *parent = nullptr);
   ~DeviceView();
 
   void SetApplication(Application *app);

src/device/giolister.h

@@ -49,7 +49,7 @@ class GioLister : public DeviceLister {
   Q_OBJECT
 
  public:
-  GioLister() {}
+  explicit GioLister() {}
   ~GioLister();
 
   int priority() const { return 50; }

src/device/gpodloader.h

@@ -40,7 +40,7 @@ class GPodLoader : public QObject {
   Q_OBJECT
 
  public:
-  GPodLoader(const QString &mount_point, TaskManager *task_manager, CollectionBackend *backend, std::shared_ptr<ConnectedDevice> device);
+  explicit GPodLoader(const QString &mount_point, TaskManager *task_manager, CollectionBackend *backend, std::shared_ptr<ConnectedDevice> device);
   ~GPodLoader();
 
   void set_music_path_prefix(const QString &prefix) { path_prefix_ = prefix; }

src/device/ilister.h

@@ -38,7 +38,7 @@
 class iLister : public DeviceLister {
   Q_OBJECT
  public:
-  iLister();
+  explicit iLister();
   ~iLister();
 
   int priority() const { return 120; }

src/device/imobiledeviceconnection.h

@@ -38,7 +38,7 @@
 
 class iMobileDeviceConnection {
 public:
-  iMobileDeviceConnection(const QString &uuid);
+  explicit iMobileDeviceConnection(const QString &uuid);
   ~iMobileDeviceConnection();
 
   afc_client_t afc() { return afc_; }

src/device/macosdevicelister.h

@@ -42,7 +42,7 @@ class MacOsDeviceLister : public DeviceLister {
   Q_OBJECT
 
  public:
-  MacOsDeviceLister();
+  explicit MacOsDeviceLister();
   ~MacOsDeviceLister();
 
   QStringList DeviceUniqueIDs();

src/device/mtpconnection.h

@@ -36,7 +36,7 @@
 
 class MtpConnection : public QObject, public std::enable_shared_from_this<MtpConnection> {
  public:
-  MtpConnection(const QUrl &url);
+  explicit MtpConnection(const QUrl &url);
   ~MtpConnection();
 
   bool is_valid() const { return device_; }

src/device/mtploader.h

@@ -39,7 +39,7 @@ class MtpLoader : public QObject {
   Q_OBJECT
 
  public:
-  MtpLoader(const QUrl &url, TaskManager *task_manager, CollectionBackend *backend);
+  explicit MtpLoader(const QUrl &url, TaskManager *task_manager, CollectionBackend *backend);
   ~MtpLoader();
 
   bool Init();

src/device/udisks2lister.h

@@ -49,7 +49,7 @@ class Udisks2Lister : public DeviceLister {
   Q_OBJECT
 
  public:
-  Udisks2Lister();
+  explicit Udisks2Lister();
   ~Udisks2Lister();
 
   QStringList DeviceUniqueIDs() override;

src/dialogs/about.h

@@ -37,7 +37,7 @@ class About : public QDialog {
   Q_OBJECT
 
  public:
-  About(QWidget *parent = nullptr);
+  explicit About(QWidget *parent = nullptr);
 
   struct Person {
     Person(const QString &n, const QString &e = QString()) : name(n), email(e) {}

src/dialogs/console.h

@@ -34,8 +34,9 @@ class Application;
 
 class Console : public QDialog {
   Q_OBJECT
+
  public:
-  Console(Application *app, QWidget *parent = nullptr);
+  explicit Console(Application *app, QWidget *parent = nullptr);
 
  private slots:
   void RunQuery();

src/dialogs/edittagdialog.h

@@ -60,7 +60,7 @@ class EditTagDialog : public QDialog {
   Q_OBJECT
 
  public:
-  EditTagDialog(Application *app, QWidget *parent = nullptr);
+  explicit EditTagDialog(Application *app, QWidget *parent = nullptr);
   ~EditTagDialog();
 
   static const char *kHintText;

src/dialogs/errordialog.h

@@ -36,7 +36,7 @@ class ErrorDialog : public QDialog {
   Q_OBJECT
 
  public:
-  ErrorDialog(QWidget *parent = nullptr);
+  explicit ErrorDialog(QWidget *parent = nullptr);
   ~ErrorDialog();
 
 public slots:

src/dialogs/trackselectiondialog.h

@@ -38,7 +38,7 @@ class TrackSelectionDialog : public QDialog {
   Q_OBJECT
 
  public:
-  TrackSelectionDialog(QWidget *parent = nullptr);
+  explicit TrackSelectionDialog(QWidget *parent = nullptr);
   ~TrackSelectionDialog();
 
   void set_save_on_close(bool save_on_close) { save_on_close_ = save_on_close; }

src/engine/alsadevicefinder.h

@@ -28,7 +28,7 @@
 
 class AlsaDeviceFinder : public DeviceFinder {
  public:
-  AlsaDeviceFinder();
+  explicit AlsaDeviceFinder();
 
   virtual bool Initialise() { return true; }
   virtual QList<Device> ListDevices();

src/engine/directsounddevicefinder.h

@@ -29,7 +29,7 @@
 
 class DirectSoundDeviceFinder : public DeviceFinder {
  public:
-  DirectSoundDeviceFinder();
+  explicit DirectSoundDeviceFinder();
 
   virtual bool Initialise() { return true; }
   virtual QList<Device> ListDevices();

src/engine/gstelementdeleter.h

@@ -32,7 +32,7 @@ class GstElementDeleter : public QObject {
   Q_OBJECT
 
  public:
-  GstElementDeleter(QObject *parent = nullptr);
+  explicit GstElementDeleter(QObject *parent = nullptr);
 
   // If you call this function with any gstreamer element, the element will get deleted in the main thread.
   // This is useful if you need to delete an element from its own callback.

src/engine/gstengine.h

@@ -57,7 +57,7 @@ class GstEngine : public Engine::Base, public GstBufferConsumer {
   Q_OBJECT
 
  public:
-  GstEngine(TaskManager *task_manager);
+  explicit GstEngine(TaskManager *task_manager);
   ~GstEngine();
 
   bool Init();

src/engine/gstenginepipeline.h

@@ -60,7 +60,7 @@ class GstEnginePipeline : public QObject {
   Q_OBJECT
 
  public:
-  GstEnginePipeline(GstEngine *engine);
+  explicit GstEnginePipeline(GstEngine *engine);
   ~GstEnginePipeline();
 
   // Globally unique across all pipelines.

src/engine/macosdevicefinder.h

@@ -29,7 +29,7 @@
 
 class MacOsDeviceFinder : public DeviceFinder {
  public:
-  MacOsDeviceFinder();
+  explicit MacOsDeviceFinder();
 
   virtual bool Initialise() { return true; }
   virtual QList<Device> ListDevices();

src/engine/mmdevicefinder.h

@@ -26,7 +26,8 @@
 
 class MMDeviceFinder : public DeviceFinder {
  public:
-  MMDeviceFinder();
+  explicit MMDeviceFinder();
+
   virtual bool Initialise() { return true; }
   virtual QList<Device> ListDevices();
 };

src/engine/phononengine.h

@@ -40,7 +40,7 @@ class PhononEngine : public Engine::Base {
   Q_OBJECT
 
  public:
-  PhononEngine(TaskManager *task_manager);
+  explicit PhononEngine(TaskManager *task_manager);
   ~PhononEngine();
 
   bool Init();

src/engine/pulsedevicefinder.h

@@ -33,7 +33,7 @@
 
 class PulseDeviceFinder : public DeviceFinder {
  public:
-  PulseDeviceFinder();
+  explicit PulseDeviceFinder();
   ~PulseDeviceFinder();
 
   virtual bool Initialise();

src/engine/vlcengine.h

@@ -42,7 +42,7 @@ class VLCEngine : public Engine::Base {
   Q_OBJECT
 
  public:
-  VLCEngine(TaskManager *task_manager);
+  explicit VLCEngine(TaskManager *task_manager);
   ~VLCEngine();
 
   bool Init();

src/engine/vlcscopedref.h

@@ -28,7 +28,7 @@
 template <typename T>
 class VlcScopedRef {
  public:
-  VlcScopedRef(T* ptr);
+  explicit VlcScopedRef(T* ptr);
   ~VlcScopedRef();
 
   operator T* () const { return ptr_; }
@@ -36,7 +36,7 @@ class VlcScopedRef {
   T* operator ->() const { return ptr_; }
 
  private:
-  VlcScopedRef(VlcScopedRef&) {}
+  explicit VlcScopedRef(VlcScopedRef&) {}
   VlcScopedRef& operator =(const VlcScopedRef&) { return *this; }
 
   T* ptr_;

src/engine/xineengine.h

@@ -48,7 +48,7 @@ class XineEngine : public Engine::Base {
     Q_OBJECT
 
  public:
-  XineEngine(TaskManager *task_manager);
+  explicit XineEngine(TaskManager *task_manager);
   ~XineEngine();
 
   bool Init();

src/equalizer/equalizer.h

@@ -41,7 +41,7 @@ class Equalizer : public QDialog {
   Q_OBJECT
 
  public:
-  Equalizer(QWidget *parent = nullptr);
+  explicit Equalizer(QWidget *parent = nullptr);
   ~Equalizer();
 
   static const int kBands = 10;

src/equalizer/equalizerslider.h

@@ -35,7 +35,7 @@ class EqualizerSlider : public QWidget {
   Q_OBJECT
 
  public:
-  EqualizerSlider(const QString &label, QWidget *parent = nullptr);
+  explicit EqualizerSlider(const QString &label, QWidget *parent = nullptr);
   ~EqualizerSlider();
 
   int value() const;

src/globalshortcuts/globalshortcutgrabber.h

@@ -47,7 +47,7 @@ class GlobalShortcutGrabber : public QDialog {
   Q_OBJECT
 
  public:
-  GlobalShortcutGrabber(QWidget *parent = nullptr);
+  explicit GlobalShortcutGrabber(QWidget *parent = nullptr);
   ~GlobalShortcutGrabber();
 
   QKeySequence GetKey(const QString &name);

src/internet/internetcollectionview.h

@@ -50,7 +50,7 @@ class InternetCollectionView : public AutoExpandingTreeView {
   Q_OBJECT
 
  public:
-  InternetCollectionView(QWidget *parent = nullptr);
+  explicit InternetCollectionView(QWidget *parent = nullptr);
   ~InternetCollectionView();
 
   void Init(Application *app, CollectionBackend *backend, CollectionModel *model, const bool favorite = false);

src/internet/internetcollectionviewcontainer.h

@@ -42,7 +42,7 @@ class InternetCollectionViewContainer : public QWidget {
   Q_OBJECT
 
  public:
-  InternetCollectionViewContainer(QWidget *parent = nullptr);
+  explicit InternetCollectionViewContainer(QWidget *parent = nullptr);
   ~InternetCollectionViewContainer();
 
   QStackedWidget *stacked() const { return ui_->stacked; }

src/internet/internetsearch.h

@@ -50,7 +50,7 @@ class InternetSearch : public QObject {
   Q_OBJECT
 
  public:
-  InternetSearch(Application *app, Song::Source source, QObject *parent = nullptr);
+  explicit InternetSearch(Application *app, Song::Source source, QObject *parent = nullptr);
   ~InternetSearch();
 
   enum SearchType {

src/internet/internetsearchitemdelegate.h

@@ -32,7 +32,7 @@ class InternetSearchView;
 
 class InternetSearchItemDelegate : public CollectionItemDelegate {
  public:
-  InternetSearchItemDelegate(InternetSearchView *view);
+  explicit InternetSearchItemDelegate(InternetSearchView *view);
 
   void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const;
 

src/internet/internetsearchmodel.h

@@ -46,7 +46,7 @@ class InternetSearchModel : public QStandardItemModel {
   Q_OBJECT
 
  public:
-  InternetSearchModel(InternetSearch *engine, QObject *parent = nullptr);
+  explicit InternetSearchModel(InternetSearch *engine, QObject *parent = nullptr);
 
   enum Role {
     Role_Result = CollectionModel::LastRole,

src/internet/internetsearchsortmodel.h

@@ -28,7 +28,7 @@ class QModelIndex;
 
 class InternetSearchSortModel : public QSortFilterProxyModel {
  public:
-  InternetSearchSortModel(QObject *parent = nullptr);
+  explicit InternetSearchSortModel(QObject *parent = nullptr);
 
  protected:
   bool lessThan(const QModelIndex &left, const QModelIndex &right) const;

src/internet/internetsearchview.h

@@ -60,7 +60,7 @@ class InternetSearchView : public QWidget {
   Q_OBJECT
 
  public:
-  InternetSearchView(QWidget *parent = nullptr);
+  explicit InternetSearchView(QWidget *parent = nullptr);
   ~InternetSearchView();
 
   void Init(Application *app, InternetSearch *engine, const QString &settings_group, const SettingsDialog::Page settings_page, const bool artists = false, const bool albums = false, const bool songs = false);

src/internet/internetservice.h

@@ -39,7 +39,7 @@ class InternetService : public QObject {
   Q_OBJECT
 
  public:
-  InternetService(Song::Source source, const QString &name, const QString &url_scheme, Application *app, QObject *parent = nullptr);
+  explicit InternetService(Song::Source source, const QString &name, const QString &url_scheme, Application *app, QObject *parent = nullptr);
 
   virtual ~InternetService() {}
   virtual void Exit() {}

src/internet/internetsongsview.h

@@ -40,7 +40,7 @@ class InternetSongsView : public QWidget {
   Q_OBJECT
 
  public:
-  InternetSongsView(Application *app, InternetService *service, const QString &settings_group, const SettingsDialog::Page settings_page, QWidget *parent = nullptr);
+  explicit InternetSongsView(Application *app, InternetService *service, const QString &settings_group, const SettingsDialog::Page settings_page, QWidget *parent = nullptr);
   ~InternetSongsView();
 
   void ReloadSettings();

src/internet/internettabsview.h

@@ -43,7 +43,7 @@ class InternetTabsView : public QWidget {
   Q_OBJECT
 
  public:
-  InternetTabsView(Application *app, InternetService *service, InternetSearch *engine, const QString &settings_group, const SettingsDialog::Page settings_page, QWidget *parent = nullptr);
+  explicit InternetTabsView(Application *app, InternetService *service, InternetSearch *engine, const QString &settings_group, const SettingsDialog::Page settings_page, QWidget *parent = nullptr);
   ~InternetTabsView();
 
   void ReloadSettings();