BUG: Ensure passing of vtkEventData to displayable managers

This commit follows up to "BUG: Fix integration with updated Slicer event
delegation and VTK OpenVR API". It ensures that existing event data objects
are consistently passed down to the `Delegate` functions and associated
displayable managers.

VirtualReality/MRML/vtkVirtualRealityViewInteractorObserver.cxx

@@ -129,7 +129,7 @@ void vtkVirtualRealityViewInteractorObserver::CustomProcessEvents(vtkObject* obj
   vtkVirtualRealityViewInteractorObserver* self
     = reinterpret_cast<vtkVirtualRealityViewInteractorObserver *>(clientdata);
 
-  if (!self->DelegateInteractionEventToDisplayableManagers(event) || self->GetInteractorStyle()->GetState() != VTKIS_NONE)
+  if (!self->DelegateInteractionEventToDisplayableManagers(event, calldata))
     {
     // Displayable managers did not process it
     vtkVirtualRealityViewInteractorObserver::ProcessEvents(object, event, clientdata, calldata);
@@ -196,6 +196,28 @@ void vtkVirtualRealityViewInteractorObserver::ProcessEvents(
 // Generic events binding
 //----------------------------------------------------------------------------
 
+//----------------------------------------------------------------------------
+bool vtkVirtualRealityViewInteractorObserver::DelegateInteractionEventToDisplayableManagers(unsigned long event, void* calldata)
+{
+  vtkSmartPointer<vtkEventData> ed;
+  if (vtkCommand::EventHasData(event))
+    {
+    ed = vtkSmartPointer(static_cast<vtkEventData*>(calldata));
+    }
+  else
+    {
+    ed = vtkSmartPointer<vtkMRMLInteractionEventData>::New();
+    ed->SetType(event);
+    }
+
+  bool delegated = this->DelegateInteractionEventToDisplayableManagers(ed);
+  if (delegated)
+    {
+    this->EventCallbackCommand->SetAbortFlag(1);
+    }
+  return delegated;
+}
+
 //----------------------------------------------------------------------------
 bool vtkVirtualRealityViewInteractorObserver::DelegateInteractionEventToDisplayableManagers(vtkEventData* inputEventData)
 {

VirtualReality/MRML/vtkVirtualRealityViewInteractorObserver.h

@@ -32,11 +32,20 @@ class VTK_SLICER_VIRTUALREALITY_MODULE_MRML_EXPORT vtkVirtualRealityViewInteract
   vtkTypeMacro(vtkVirtualRealityViewInteractorObserver,vtkMRMLViewInteractorStyle);
   void PrintSelf(ostream& os, vtkIndent indent) override;
 
+  using vtkMRMLViewInteractorStyle::DelegateInteractionEventToDisplayableManagers;
+
+  /// Give a chance to displayable managers to process the event.
+  /// Based on the return of vtkCommand::EventHasData(event), it either casts the
+  /// calldata to a vtkEventData or just creates a one of type vtkMRMLInteractionEventData.
+  /// In both case, it calls DelegateInteractionEventDataToDisplayableManagers
+  /// passing a vtkEventData object.
+  /// Return true if the event is processed.
+  virtual bool DelegateInteractionEventToDisplayableManagers(unsigned long event, void* calldata);
+
   /// Give a chance to displayable managers to process the event.
-  /// It just creates vtkMRMLInteractionEventData and calls
+  /// It creates vtkMRMLInteractionEventData and calls
   /// DelegateInteractionEventDataToDisplayableManagers.
   /// Return true if the event is processed.
-  using vtkMRMLViewInteractorStyle::DelegateInteractionEventToDisplayableManagers;
   bool DelegateInteractionEventToDisplayableManagers(vtkEventData* inputEventData) override;
 
   /// Give a chance to displayable managers to process the event.