Use new getter for clarity (avoid negation) (#242)

Author: alxvth

src/ScatterplotPlugin.cpp

@@ -569,7 +569,7 @@ void ScatterplotPlugin::selectPoints()
 
     auto& navigationAction = navigator.getNavigationAction();
 
-    navigationAction.getZoomSelectionAction().setEnabled(!targetSelectionIndices.empty() && !navigationAction.getFreezeNavigation().isChecked());
+    navigationAction.getZoomSelectionAction().setEnabled(!targetSelectionIndices.empty() && navigationAction.isNavigationActive());
 
     _positionDataset->setSelectionIndices(targetSelectionIndices);