T66 Tidying up CBackgroundDataUpdater startup and shutdown

by overriding the CContinuousWorker virtual methods that exist for this purpose.

src/blackcore/db/backgrounddataupdater.cpp

@@ -37,9 +37,20 @@ namespace BlackCore
             CContinuousWorker(owner, "Background data updater")
         {
             connect(&m_updateTimer, &QTimer::timeout, this, &CBackgroundDataUpdater::doWork);
+        }
+
+        void CBackgroundDataUpdater::initialize()
+        {
             m_updateTimer.start(60 * 1000);
         }
 
+        void CBackgroundDataUpdater::cleanup()
+        {
+            m_updateTimer.stop();
+            m_shutdown = true;
+            m_enabled = false;
+        }
+
         CBackgroundDataUpdater::~CBackgroundDataUpdater()
         {
             gracefulShutdown();
@@ -60,18 +71,12 @@ namespace BlackCore
 
         void CBackgroundDataUpdater::gracefulShutdown()
         {
-            if (m_shutdown) { return; }
             m_shutdown = true;
             m_enabled = false;
             if (!CThreadUtils::isCurrentThreadObjectThread(this))
             {
                 this->abandonAndWait();
             }
-            else
-            {
-                // timer needs to be stopped in its own thread
-                m_updateTimer.stop();
-            }
         }
 
         void CBackgroundDataUpdater::startUpdating(int updateTimeSecs)

src/blackcore/db/backgrounddataupdater.h

@@ -38,6 +38,12 @@ namespace BlackCore
             //! Destructor
             virtual ~CBackgroundDataUpdater();
 
+            //! \copydoc BlackMisc::CContinuousWorker::initialize
+            virtual void initialize() override;
+
+            //! \copydoc BlackMisc::CContinuousWorker::cleanup
+            virtual void cleanup() override;
+
             //! Is shutting down?
             //! \threadsafe
             bool isShuttingDown() const;