slider: start listening to mouse input only after positioning

app/widget/slider/sliderbase.cpp

@@ -396,6 +396,8 @@ void SliderBase::RepositionLadder()
 
       drag_ladder_->move(ladder_x, ladder_y);
     }
+
+    drag_ladder_->StartListeningToMouseInput();
   }
 }
 

app/widget/slider/sliderladder.cpp

@@ -113,6 +113,11 @@ void SliderLadder::SetValue(const QString &s)
   }
 }
 
+void SliderLadder::StartListeningToMouseInput()
+{
+  drag_timer_.start();
+}
+
 void SliderLadder::mouseReleaseEvent(QMouseEvent *event)
 {
   Q_UNUSED(event)
@@ -120,13 +125,6 @@ void SliderLadder::mouseReleaseEvent(QMouseEvent *event)
   this->close();
 }
 
-void SliderLadder::showEvent(QShowEvent *event)
-{
-  QWidget::showEvent(event);
-
-  drag_timer_.start();
-}
-
 void SliderLadder::closeEvent(QCloseEvent *event)
 {
   Q_UNUSED(event)
@@ -134,6 +132,8 @@ void SliderLadder::closeEvent(QCloseEvent *event)
   drag_timer_.stop();
 
   emit Released();
+
+  QFrame::closeEvent(event);
 }
 
 void SliderLadder::TimerUpdate()

app/widget/slider/sliderladder.h

@@ -70,11 +70,11 @@ public:
 
   void SetValue(const QString& s);
 
+  void StartListeningToMouseInput();
+
 protected:
   virtual void mouseReleaseEvent(QMouseEvent *event) override;
 
-  virtual void showEvent(QShowEvent *event) override;
-
   virtual void closeEvent(QCloseEvent* event) override;
 
 signals: