Method OnMiddleButtonDown

Interaction/Style/vtkInteractorStyleUser.cxx:220–240

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
void vtkInteractorStyleUser::OnMiddleButtonDown()
{
  this->Button = 2;

  if (this->HasObserver(vtkCommand::MiddleButtonPressEvent))
  {
    int x = this->Interactor->GetEventPosition()[0];
    int y = this->Interactor->GetEventPosition()[1];
    this->CtrlKey = this->Interactor->GetControlKey();
    this->ShiftKey = this->Interactor->GetShiftKey();
    this->LastPos[0] = x;
    this->LastPos[1] = y;
    this->InvokeEvent(vtkCommand::MiddleButtonPressEvent, nullptr);
    this->OldPos[0] = x;
    this->OldPos[1] = y;
  }
  else
  {
    this->vtkInteractorStyle::OnMiddleButtonDown();
  }
}
//------------------------------------------------------------------------------
void vtkInteractorStyleUser::OnMiddleButtonUp()
{