Core: minor cleanup in Instrument context

GUI/Models/TransformFromDomain.cpp

@@ -505,13 +505,13 @@ void GUI::Transform::FromDomain::setSpecularBeamItem(SpecularBeamItem* beam_item
 void GUI::Transform::FromDomain::setDetector(Instrument2DItem* instrument_item,
                                              const ISimulation2D& simulation)
 {
-    const IDetector* p_detector = simulation.instrument().getDetector();
-    setDetectorGeometry(instrument_item, *p_detector);
+    const IDetector& detector = simulation.detector();
+    setDetectorGeometry(instrument_item, detector);
 
     auto detector_item = instrument_item->detectorItem();
 
-    setDetectorResolution(detector_item, *p_detector);
-    setDetectorProperties(detector_item, *p_detector);
+    setDetectorResolution(detector_item, detector);
+    setDetectorProperties(detector_item, detector);
     setDetectorMasks(detector_item, simulation);
 }
 
@@ -651,16 +651,16 @@ void GUI::Transform::FromDomain::setRectangularDetector(RectangularDetectorItem*
 void GUI::Transform::FromDomain::setDetectorMasks(DetectorItem* detector_item,
                                                   const ISimulation& simulation)
 {
-    const IDetector* detector = simulation.instrument().getDetector();
-    if ((detector->detectorMask() && detector->detectorMask()->hasMasks())
-        || detector->hasExplicitRegionOfInterest()) {
+    const IDetector& detector = simulation.detector();
+    if ((detector.detectorMask() && detector.detectorMask()->hasMasks())
+        || detector.hasExplicitRegionOfInterest()) {
 
         detector_item->createMaskContainer();
         double scale(1.0);
         if (detector_item->modelType() == SphericalDetectorItem::M_TYPE)
             scale = 1. / Units::deg;
 
-        setMaskContainer(detector_item->maskContainerItem(), *detector, scale);
+        setMaskContainer(detector_item->maskContainerItem(), detector, scale);
     }
 }