- int keypress_event();
- int button_press_event();
- int button_release_event();
- int cursor_motion_event();
+ virtual int keypress_event();
+ virtual int button_press_event() { return 0; }
+ virtual int button_release_event() { return 0; }
+ virtual int cursor_motion_event() { return 0; }
+ virtual void draw_vframe(VFrame *frame);
+ int zoom_scale(int dir);