function Keyboard() { this.listen = function(event) { console.log(dotgrid); console.log(event.keyCode); switch (event.key || event.keyCode) { case 65 : dotgrid.draw_arc_a(); break; case 83 : dotgrid.draw_arc_c(); break; case 68 : dotgrid.draw_line(); break; case 70 : dotgrid.reset(); break; } } }