在被动视图模式中创建子视图

Question

我对使用被动视图模式来提高可测试性非常感兴趣，但我不确定如何调用子对话框。

您是否让父视图创建子视图并向父控制器返回接口，然后让父控制器创建子控制器？

Answer 1

我一直在思考这个问题，我想我有几个可能的解决方案。

1. 在视图类中添加一个方法来生成下级对话框
2. 创建一个生成模型、视图的工厂。和下级对话框的控制器

方法一

class ParentView extends JDialog implements IParentView {
  public IChildView newChildView(...) {
    return new ChildView(...);
  }
  // ...
}

interface IParentView {
  IChildView newChildView(...);
  // ...
}

class ParentController {
  private IParentView view;
  public ParentController(IParentView view) {
    this.view  = view;
  }

  public void showChildView() {
    IChildView childView = view.newChildView();
    ChildController childController = new ChildController(childView);
    childView.setVisible(true);
  }
}

class ChildView extends JDialog implements IChildView {
  // ...
}

interface IChildView {
  void setVisible(boolean visible);
}

class ChildController {
  private IChildView view;
  public ChildController(IChildView view) {
    this.view = view;
  }
}

方法二

// During testing, create a mock ChildFactory and assign it to instance
class ChildFactory implements IChildFactory {
    private static IChildFactory instance;
    public static ChildFactory getInstance() {
      if (instance == null) {
        instance = new ChildFactory();
      }
      return instance;
    }
    public static void setInstance(IChildFactory factory) {
      instance = factory;
    }
    public void createChild(IParentView parent) {
      IChildView view = new ChildView(parent);
      ChildController controller = new ChildController(view);
      view.setVisible(true);
    }
}

interface IChildFactory {
  void createChild(IParentView parent);
}

class ParentController {
  private IParentView view;
  public ParentController(IParentView view) {
    this.view  = view;
  }
  public void showChildView() {
    ChildFactory.getInstance().createChild(view);
  }
}

// ParentView class similar to method 1