tablet::tablet(widget* w, char* options)  
\fbox{tablet}
: canvas(w,"tablet",0) {
(a)

widget* top = new frame(path()); init(options); redirect(c);
(b)

handler(this);
(c)

handlers[drawmode::move] = new move_handler(this); handlers[drawmode::box] = new box_handler(this); handlers[drawmode::circle] = new circle_handler(this); handlers[drawmode::arrow]=new arrow_handler(this); _mode = drawmode::move; }

slide: Installing the handlers