MiddleButton      638 modules/viz/src/vtk/vtkVizInteractorStyle.cpp     MouseEvent event(type, MouseEvent::MiddleButton, p, getModifiers());
MiddleButton      654 modules/viz/src/vtk/vtkVizInteractorStyle.cpp     MouseEvent event(MouseEvent::MouseButtonRelease, MouseEvent::MiddleButton, p, getModifiers());