ENH: Remove obsolete "GestureEnabledButtons" ivar from interactor class

Removes "GestureEnabledButtons" ivar that became obsolete following
these commits:
* c5c6d6f ("BUG: Restore complex gesture support", 2023-01-29),
* 22eba9f ("BUG: Fix integration with updated Slicer event delegation and VTK OpenVR API (KitwareMedical#131)", 2023-12-21)
* 0fa6102 ("BUG: Ensure handling of gesture triggers the "End" event", 2023-12-20)
* 512efe6 ("BUG: Do not report "Unrecognized device" if handling complex gesture", 2023-12-20)

For reference, it was originally introduced in 43bef4b ("ENH: Make trigger
button configurable", 2019-01-11).

VirtualReality/MRMLDM/vtkVirtualRealityViewInteractor.cxx

@@ -33,7 +33,6 @@ vtkStandardNewMacro(vtkVirtualRealityViewInteractor);
 //----------------------------------------------------------------------------
 vtkVirtualRealityViewInteractor::vtkVirtualRealityViewInteractor()
 {
-  this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Grip));
 }
 
 //----------------------------------------------------------------------------
@@ -214,17 +213,10 @@ void vtkVirtualRealityViewInteractor::SetTriggerButtonFunction(std::string funct
   if (functionId.empty())
   {
     vrInteractorStyle->MapInputToAction(vtkCommand::Select3DEvent, VTKIS_NONE);
-
-    this->GestureEnabledButtons.clear();
-    this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Grip));
   }
   else if (!functionId.compare(vtkVirtualRealityViewInteractor::GetButtonFunctionIdForGrabObjectsAndWorld()))
   {
     vrInteractorStyle->MapInputToAction(vtkCommand::Select3DEvent, VTKIS_POSITION_PROP);
-
-    this->GestureEnabledButtons.clear();
-    this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Grip));
-    this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Trigger));
   }
   else
   {
@@ -249,9 +241,6 @@ void vtkVirtualRealityViewInteractor::SetGestureButtonToTrigger()
   this->AddAction("/actions/vtk/in/TriggerAction", /*isAnalog=*/false,
                   [this](vtkEventData* ed) { this->HandleComplexGestureEvents(ed); });
   this->AddAction("/actions/vtk/in/ComplexGestureAction", vtkCommand::Select3DEvent, /*isAnalog=*/false);
-
-  this->GestureEnabledButtons.clear();
-  this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Trigger));
 }
 
 //----------------------------------------------------------------------------
@@ -271,9 +260,6 @@ void vtkVirtualRealityViewInteractor::SetGestureButtonToGrip()
   this->AddAction("/actions/vtk/in/TriggerAction", vtkCommand::Select3DEvent, /*isAnalog=*/false);
   this->AddAction("/actions/vtk/in/ComplexGestureAction", /*isAnalog=*/false,
                   [this](vtkEventData* ed) { this->HandleComplexGestureEvents(ed); });
-
-  this->GestureEnabledButtons.clear();
-  this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Grip));
 }
 
 //----------------------------------------------------------------------------
@@ -294,10 +280,6 @@ void vtkVirtualRealityViewInteractor::SetGestureButtonToTriggerAndGrip()
                   [this](vtkEventData* ed) { this->HandleComplexGestureEvents(ed); });
   this->AddAction("/actions/vtk/in/ComplexGestureAction", /*isAnalog=*/false,
                   [this](vtkEventData* ed) { this->HandleComplexGestureEvents(ed); });
-
-  this->GestureEnabledButtons.clear();
-  this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Grip));
-  this->GestureEnabledButtons.push_back(static_cast<int>(vtkEventDataDeviceInput::Trigger));
 }
 
 //----------------------------------------------------------------------------
@@ -318,6 +300,4 @@ void vtkVirtualRealityViewInteractor::SetGestureButtonToNone()
                   [](vtkEventData* vtkNotUsed(ed)) { });
   this->AddAction("/actions/vtk/in/ComplexGestureAction", /*isAnalog=*/false,
                   [](vtkEventData* vtkNotUsed(ed)) { });
-
-  this->GestureEnabledButtons.clear();
 }

VirtualReality/MRMLDM/vtkVirtualRealityViewInteractor.h

@@ -79,11 +79,6 @@ class VTK_SLICER_VIRTUALREALITY_MODULE_MRMLDISPLAYABLEMANAGER_EXPORT vtkVirtualR
   void SetGestureButtonToNone();
   ///@}
 
-protected:
-
-  /// List of buttons for which gesture recognition is enabled
-  std::vector<int> GestureEnabledButtons;
-
 private:
   vtkVirtualRealityViewInteractor();
   ~vtkVirtualRealityViewInteractor() override;