fixed #571

ui/panel.cpp

@@ -37,6 +37,13 @@ Panel::~Panel()
   olive::panels.removeAll(this);
 }
 
+void Panel::LoadLayoutState(const QByteArray &) {}
+
+QByteArray Panel::SaveLayoutState()
+{
+  return QByteArray();
+}
+
 void Panel::changeEvent(QEvent *e)
 {
   if (e->type() == QEvent::LanguageChange) {

ui/panel.h

@@ -28,7 +28,11 @@ class Panel : public QDockWidget {
 public:
   Panel(QWidget* parent = nullptr);
   virtual ~Panel() override;
+
   virtual void Retranslate() = 0;
+
+  virtual void LoadLayoutState(const QByteArray& data);
+  virtual QByteArray SaveLayoutState();
 protected:
   virtual void changeEvent(QEvent* e) override;
 };