BUG: allow DisableMouseInteraction in LaparoscopicCamera

In the LaparoscopicCamera example the mouse interaction
was supposed to be disabled, but by setting the new
interactor style after the viewer initialization, the
observers rules on the vtkViewer interactor were
overridden. Placing the interactorStyle beforehand
resolves the issue.

In the future it would be convenient to have wrapped
functions in IMSTK to make changes to the interactor
without the need to go through VTK.

Examples/LaparoscopicCamera/main.cpp

@@ -410,33 +410,35 @@ int main()
     //-------------------------------------------------------
     // Set up the scene
     //-------------------------------------------------------
-
     std::shared_ptr<Scene> scene = sdk->getScene(0);
     viewer->registerScene(scene, SMRENDERTARGET_SCREEN, "Collision pipeline demo");
 
     // Create camera navigation scene
     createCameraNavigationScene(scene, "./CameraNavAppData/target.png");
 
-    // Initialize viewer with scene objects
-    // NOTE : Needs to be done before VTK Add ons since
-    // init create the needed renderer in the VTKView
-    viewer->init();
-
     //-------------------------------------------------------
-    // Add ons (VTK)
-    //-------------------------------------------------------
-
     // Enable screenshot capture
+    //-------------------------------------------------------
+    // NOTE : Needs to be done before the viewer initialisation
+    // not to erase the changes on the observers made to the
+    // interactor in vtkViewer::addRenderer()
     vtkNew<ScreenCaptureInteractorStyle> style;
     style->initialize(vtkViewer->getRenderWindow());
     vtkViewer->getVtkRenderWindowInteractor()->SetInteractorStyle(style.GetPointer());
     style->SetCurrentRenderer(vtkViewer->getVtkRenderer());
 
+    //-------------------------------------------------------
+    // Initialize viewer with scene objects
+    //-------------------------------------------------------
+    // NOTE : Needs to be done before VTK Add ons since
+    // init create the needed renderer in the VTKViewer
+    viewer->init();
+
+    //-------------------------------------------------------
+    // Add ons (VTK)
+    //-------------------------------------------------------
     // Add a camera controller
-    // NOTE: This has to come after the ScreenCaptureInteractorStyle initialization
-    // since for this to work the mouse events need disabled which are
-    // left as is after ScreenCaptureInteractorStyle initialization
-    std::shared_ptr<LaparoscopicCameraController> camController = addCameraController(sdk);
+    addCameraController(sdk);
 
     // Add a 2D overlay on the 3D scene
     add2DOverlay(vtkViewer,"./CameraNavAppData/viewfinder.png");
@@ -444,7 +446,6 @@ int main()
     //-------------------------------------------------------
     // Start
     //-------------------------------------------------------
-
     // Run the SDK
     sdk->run();