def load_extra_vi_page_navigation_bindings():
 registry = ConditionalRegistry(Registry(), ViMode())
 handle = registry.add_binding
 handle(Keys.ControlF)(scroll_forward)
 handle(Keys.ControlB)(scroll_backward)
 handle(Keys.ControlD)(scroll_half_page_down)
 handle(Keys.ControlU)(scroll_half_page_up)
 handle(Keys.ControlE)(scroll_one_line_down)
 handle(Keys.ControlY)(scroll_one_line_up)
 handle(Keys.PageDown)(scroll_page_down)
 handle(Keys.PageUp)(scroll_page_up)
 return registry

def load_extra_vi_page_navigation_bindings ( ) : registry = ConditionalRegistry ( Registry ( ) , ViMode ( ) ) handle = registry . add_binding handle ( Keys . ControlF ) ( scroll_forward ) handle ( Keys . ControlB ) ( scroll_backward ) handle ( Keys . ControlD ) ( scroll_half_page_down ) handle ( Keys . ControlU ) ( scroll_half_page_up ) handle ( Keys . ControlE ) ( scroll_one_line_down ) handle ( Keys . ControlY ) ( scroll_one_line_up ) handle ( Keys . PageDown ) ( scroll_page_down ) handle ( Keys . PageUp ) ( scroll_page_up ) return registry
key bindings .