ClassView: Use new setup pattern for navigationwidget factory

Change-Id: I4e519d068c1ce85b6aee6e8743104703f6ddda8a
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/classview/classviewnavigationwidgetfactory.cpp

@@ -6,16 +6,15 @@
 #include "classviewnavigationwidget.h"
 #include "classviewtr.h"
 
+#include <coreplugin/inavigationwidgetfactory.h>
+
 #include <utils/qtcassert.h>
 #include <utils/qtcsettings.h>
 #include <utils/store.h>
 
 using namespace Utils;
 
-namespace ClassView {
-namespace Internal {
-
-///////////////////////////////// NavigationWidgetFactory //////////////////////////////////
+namespace ClassView::Internal {
 
 /*!
     \class NavigationWidgetFactory
@@ -26,6 +25,16 @@ namespace Internal {
     removing it from \c ExtensionSystem::PluginManager.
 */
 
+class NavigationWidgetFactory final : public Core::INavigationWidgetFactory
+{
+public:
+    NavigationWidgetFactory();
+
+    Core::NavigationView createWidget() final;
+    void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget) final;
+    void restoreSettings(Utils::QtcSettings *settings, int position, QWidget *widget) final;
+};
+
 NavigationWidgetFactory::NavigationWidgetFactory()
 {
     setDisplayName(Tr::tr("Class View"));
@@ -70,5 +79,9 @@ void NavigationWidgetFactory::restoreSettings(QtcSettings *settings, int positio
     pw->setFlatMode(settings->value(settingsGroup, false).toBool());
 }
 
-} // namespace Internal
-} // namespace ClassView
+void setupClassViewNavigationWidgetFactory()
+{
+    static NavigationWidgetFactory theNavigationWidgetFactory;
+}
+
+} // ClassView::Internal

src/plugins/classview/classviewnavigationwidgetfactory.h

@@ -3,18 +3,8 @@
 
 #pragma once
 
-#include <coreplugin/inavigationwidgetfactory.h>
-
 namespace ClassView::Internal {
 
-class NavigationWidgetFactory : public Core::INavigationWidgetFactory
-{
-public:
-    NavigationWidgetFactory();
-
-    Core::NavigationView createWidget() override;
-    void saveSettings(Utils::QtcSettings *settings, int position, QWidget *widget) override;
-    void restoreSettings(Utils::QtcSettings *settings, int position, QWidget *widget) override;
-};
+void setupClassViewNavigationWidgetFactory();
 
 } // ClassView::Internal

src/plugins/classview/classviewplugin.cpp

@@ -22,7 +22,6 @@ namespace Internal {
 class ClassViewPluginPrivate
 {
 public:
-    NavigationWidgetFactory navigationWidgetFactory;
     Manager manager;
 };
 
@@ -36,6 +35,7 @@ ClassViewPlugin::~ClassViewPlugin()
 
 void ClassViewPlugin::initialize()
 {
+    setupClassViewNavigationWidgetFactory();
     dd = new ClassViewPluginPrivate;
 }