练习 3-1

public class Window {
    private String text = "";
    public Window(String text) {
        this.text = text;
    }
    public void print() {
        System.out.println("print " + this.text);
    }
}

public class Container extends Window  {
    private List<Window> children = new LinkedList<>();
    public Container(String text) {
        super(text);
    }
    public void addChild(Window child) {
        this.children.add(child);
    }
    public void print() {
        for(Window child:children){
            child.print();
        }
    }
}

public class Button extends Window  {
    public Button(String text) {
        super(text);
    }
}

public class CheckBox extends Window  {
    public CheckBox(String text) {
        super(text);
    }
}

public class Frame extends Container {
    public Frame(String text) {
        super(text);
    }
}

public class Lable extends Window  {
    public Lable(String text) {
        super(text);
    }
}

public static void main(String[] args) {
  WinForm winForm = new WinForm("WinForm(WINDOW窗口)");
  winForm.addChild(new Picture("Picture(LOG图片)"));
  winForm.addChild(new Button("Button(登录)"));
  winForm.addChild(new Button("Button(注册)"));
  Frame frame = new Frame("FRAME(FRAME1)");
  frame.addChild(new Lable("Lable(用户名)"));
  frame.addChild(new TextBox("TextBox(文本框)"));
  frame.addChild(new Lable("Lable(密码)"));
  frame.addChild(new PasswordBox("PasswordBox(密码框)"));
  frame.addChild(new CheckBox("CheckBox(复选框)"));
  frame.addChild(new TextBox("TextBox(记住用户名)"));
  frame.addChild(new LinkLable("LinkLable(忘记密码)"));
  winForm.addChild(frame);
  winForm.print();
}