Gui: refactor gizmo attachment code

src/Gui/ViewProviderDragger.cpp

@@ -39,6 +39,7 @@
 #include "Control.h"
 #include "Document.h"
 #include "Inventor/Draggers/SoTransformDragger.h"
+#include "Inventor/Draggers/Gizmo.h"
 #include "Inventor/SoFCPlacementIndicatorKit.h"
 #include "SoFCUnifiedSelection.h"
 #include "TaskTransform.h"
@@ -94,6 +95,12 @@ void ViewProviderDragger::resetTransformOrigin()
     setTransformOrigin({});
 }
 
+
+void ViewProviderDragger::setGizmoContainer(Gui::GizmoContainer* gizmoContainer)
+{
+    this->gizmoContainer = gizmoContainer;
+}
+
 void ViewProviderDragger::onChanged(const App::Property* property)
 {
     if (property == &TransformOrigin) {
@@ -221,7 +228,11 @@ void ViewProviderDragger::setEditViewer(Gui::View3DInventorViewer* viewer, int M
 {
     Q_UNUSED(ModNum);
 
-    if (transformDragger && viewer) {
+    if (!viewer) {
+        return;
+    }
+
+    if (transformDragger) {
         transformDragger->setUpAutoScale(viewer->getSoRenderManager()->getCamera());
 
         auto originPlacement = App::GeoFeature::getGlobalPlacement(getObject()) * getObjectPlacement().inverse();
@@ -230,6 +241,12 @@ void ViewProviderDragger::setEditViewer(Gui::View3DInventorViewer* viewer, int M
         viewer->getDocument()->setEditingTransform(mat);
         viewer->setupEditingRoot(transformDragger, &mat);
     }
+
+    if (gizmoContainer) {
+        auto originPlacement = App::GeoFeature::getGlobalPlacement(getObject())
+            * getObjectPlacement().inverse();
+        gizmoContainer->attachViewer(viewer, originPlacement);
+    }
 }
 
 void ViewProviderDragger::unsetEditViewer([[maybe_unused]] Gui::View3DInventorViewer* viewer)