- void button_press(unsigned);
- void axis_motion(unsigned, float, float);
- void selection_changed();
- void update_objects();
- void update_neighbors();
- void set_slope(TrackOrder &, float, float);
- std::vector<R2C2::Track *> create_straight(const R2C2::Vector &, const R2C2::Angle &, float, float);