Add new method for updating songs based on song ID

Show status updating database.

Fixes #750

src/core/metatypes.cpp

@@ -99,8 +99,10 @@ void RegisterMetaTypes() {
   qRegisterMetaType<Subdirectory>("Subdirectory");
   qRegisterMetaType<SubdirectoryList>("SubdirectoryList");
   qRegisterMetaType<Song>("Song");
-  qRegisterMetaType<QList<Song>>("QList<Song>");
   qRegisterMetaType<SongList>("SongList");
+  qRegisterMetaType<SongMap>("SongMap");
+  qRegisterMetaType<QList<Song>>("QList<Song>");
+  qRegisterMetaType<QMap<QString, Song>>("QMap<QString, Song>");
   qRegisterMetaType<Engine::EngineType>("EngineType");
   qRegisterMetaType<Engine::SimpleMetaBundle>("Engine::SimpleMetaBundle");
   qRegisterMetaType<Engine::State>("Engine::State");

src/core/scopedtransaction.cpp

@@ -25,19 +25,23 @@
 #include "core/logging.h"
 #include "scopedtransaction.h"
 
-ScopedTransaction::ScopedTransaction(QSqlDatabase *db)
-    : db_(db), pending_(true) {
+ScopedTransaction::ScopedTransaction(QSqlDatabase *db) : db_(db), pending_(true) {
+
   db->transaction();
+
 }
 
 ScopedTransaction::~ScopedTransaction() {
+
   if (pending_) {
     qLog(Warning) << "Rolling back transaction";
     db_->rollback();
   }
+
 }
 
 void ScopedTransaction::Commit() {
+
   if (!pending_) {
     qLog(Warning) << "Tried to commit a ScopedTransaction twice";
     return;
@@ -45,4 +49,5 @@ void ScopedTransaction::Commit() {
 
   db_->commit();
   pending_ = false;
+
 }

src/core/song.h

@@ -30,6 +30,7 @@
 #include <QMetaType>
 #include <QList>
 #include <QSet>
+#include <QMap>
 #include <QVariant>
 #include <QString>
 #include <QStringList>
@@ -396,10 +397,13 @@ class Song {
 
   QSharedDataPointer<Private> d;
 };
-Q_DECLARE_METATYPE(Song)
 
 typedef QList<Song> SongList;
-Q_DECLARE_METATYPE(QList<Song>)
+typedef QMap<QString, Song> SongMap;
+
+Q_DECLARE_METATYPE(Song)
+Q_DECLARE_METATYPE(SongList)
+Q_DECLARE_METATYPE(SongMap)
 
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 size_t qHash(const Song &song);