balllistinterface.java~

来自「书籍"Java_面向事件编程"的附带光盘代码」· JAVA~ 代码 · 共 22 行

import objectdraw.*;

/*
 * A list of FilledOvals.  This interface
 * captures what is common about all lists.
 */
public interface BallListInterface {
    
    // Returns true if the list is empty
    public boolean isEmpty();
    
    // Returns the first ball in the list
    // pre: the list is not an empty list.
    public FilledOval getFirst();
        
    // Returns the rest of the list, after
    // the first ball.
    // pre: the list is not an empty list.
    public BallListInterface getRest();
    
}