module type SigCb =sig..end
type t_env
val button_one_press_on_graph : t_env -> unitval button_two_press_on_graph : t_env -> unitval button_three_press_on_graph : t_env -> unitval button_one_press_on_node : t_env -> ViewGraph_core.t_node -> unitval button_two_press_on_node : t_env -> ViewGraph_core.t_node -> unitval button_three_press_on_node : t_env -> ViewGraph_core.t_node -> unitval enter_node : t_env -> ViewGraph_core.t_node -> unitval leave_node : t_env -> ViewGraph_core.t_node -> unit