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);
};