QmlDesigner: Fix double creation of DVConnector

DVConnector is created twice once for the toolbar instance and another
time for the statusbar instance in QML. Fix this by making the
DVConnector a static unique_ptr.

Change-Id: Ib8dc18154bbb7915860d182dd5b66626bc3e60d6
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/components/toolbar/toolbarbackend.cpp

@@ -48,6 +48,8 @@
 
 #include <QQmlEngine>
 
+#include <memory>
+
 namespace QmlDesigner {
 
 static Internal::DesignModeWidget *designModeWidget()
@@ -349,6 +351,10 @@ void ActionSubscriber::setupNotifier()
     emit tooltipChanged();
 }
 
+#ifdef DVCONNECTOR_ENABLED
+static std::unique_ptr<DesignViewer::DVConnector> s_designViewerConnector;
+#endif
+
 ToolBarBackend::ToolBarBackend(QObject *parent)
     : QObject(parent)
 {
@@ -929,7 +935,10 @@ QString ToolBarBackend::runManagerError() const
 #ifdef DVCONNECTOR_ENABLED
 DesignViewer::DVConnector *ToolBarBackend::designViewerConnector()
 {
-    return &m_designViewerConnector;
+    if (!s_designViewerConnector)
+        s_designViewerConnector = std::make_unique<DesignViewer::DVConnector>();
+
+    return s_designViewerConnector.get();
 }
 #endif
 

src/plugins/qmldesigner/components/toolbar/toolbarbackend.h

@@ -232,9 +232,6 @@ private:
 
     QStringList m_openDocuments;
     QMetaObject::Connection m_kitConnection;
-#ifdef DVCONNECTOR_ENABLED
-    DesignViewer::DVConnector m_designViewerConnector;
-#endif
 };
 
 } // namespace QmlDesigner