bool is_valid()const { return (bool)stroke_data; }
sigc::signal<void,float> &signal_user_click(int i=0) { assert(i>=0); assert(i<5); return signal_user_click_[i]; }
bool is_valid()const { return (bool)stroke_data; }
sigc::signal<void,float> &signal_user_click(int i=0) { assert(i>=0); assert(i<5); return signal_user_click_[i]; }