ballcollectioninterface.java

来自「书籍"Java_面向事件编程"的附带光盘代码」· Java 代码 · 共 12 行

public interface BallCollectionInterface {
    // Return a random ball from the collection
    public BBall pickRandomly();
    
    // hide all the balls
    public void hide();
    
    // show all the balls
    public void show();
}