public interface widget { 
widget
public String path(); public void eval(String cmd); public void pack(String s); public void bind(handler h,String s); public void bind(String p, handler h,String s); public void configure(String cmd); public void geometry(int x, int y); public void xscroll(widget w); public void yscroll(widget w); public widget self(); // to define compound widgets public void redirect(widget inner); };