android - Mortar + Flow 与连接到 Activity 生命周期的第三方库

Question

一些第三方库在 Activity 生命周期中使用 Hook 来正常工作 - 例如，Facebook SDK (https://developers.facebook.com/docs/android/login-with-facebook/)。

我在弄清楚如何将此模型与单 Activity 流程 + 砂浆设置完全协调时遇到了一些麻烦。

例如，如果我想使用 Facebook 登录作为登录流(w/FlowView/FlowOwner)的一部分，但不是在 Activity 中，如果您需要该特定流的 Hook ，那么最聪明的方法是什么？在 onCreate、onResume、onPause、onDestroy、onSaveInstanceState、onActivityResult 等？

最干净的路径是什么并不是很明显 - 为每个生命周期 Activity 阶段创建一个 observable 并订阅它的流？如果您不小心，似乎这条路径很快就会转移到相同的 Android 生命周期。有没有更好的办法？

我喜欢单一 Activity 模型，如果可能的话，我真的希望一切都由流/迫击炮而不是 Activity 来管理。还是我在考虑这件事的方式从根本上使它变得比应有的更困难？

Answer 1

到目前为止，我们还不需要开始和停止，但确实有一些地方需要暂停和恢复。我们按照您的建议使用 ActivityPresenter，但避免使用任何类型的通用父类(super class)。相反，它公开了感兴趣的演示者可以选择加入的服务。这种连接需求是添加 onEnterScope(Scope) 方法的原因。这是代码。

首先，让 Activity 实现这个接口(interface):

/**
 * Implemented by {@link android.app.Activity} instances whose pause / resume state
 * is to be shared. The activity must call {@link PauseAndResumePresenter#activityPaused()}
 * and {@link PauseAndResumePresenter#activityResumed()} at the obvious times.
 */
public interface PauseAndResumeActivity {
  boolean isRunning();

  MortarScope getMortarScope();
}

并让它注入(inject)演示者并进行适当的调用:

private boolean resumed;
@Inject PauseAndResumePresenter pauseNarcPresenter;

@Override protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  pauseNarcPresenter.takeView(this);
}

@Override public boolean isRunning() {
  return resumed;
}

@Override protected void onResume() {
  super.onResume();
  resumed = true;
  pauseNarcPresenter.activityResumed();
}

@Override protected void onPause() {
  resumed = false;
  super.onPause();
  pauseNarcPresenter.activityPaused();
}

@Override protected void onDestroy() {
  pauseNarcPresenter.dropView(this);
  super.onDestroy();
}

现在感兴趣的各方可以注入(inject)一个注册商接口(interface)来选择暂停和恢复通话，而无需继承任何内容。

/**
 * Provides means to listen for {@link android.app.Activity#onPause()} and {@link
 * android.app.Activity#onResume()}.
 */
public interface PauseAndResumeRegistrar {
  /**
   * <p>Registers a {@link PausesAndResumes} client for the duration of the given {@link
   * MortarScope}. This method is debounced, redundant calls are safe.
   *
   * <p>Calls {@link PausesAndResumes#onResume()} immediately if the host {@link
   * android.app.Activity} is currently running.
   */
  void register(MortarScope scope, PausesAndResumes listener);

  /** Returns {@code true} if called between resume and pause. {@code false} otherwise. */
  boolean isRunning();
}

让客户端演示者实现这个接口(interface):

/**
 * <p>Implemented by objects that need to know when the {@link android.app.Activity} pauses
 * and resumes. Sign up for service via {@link PauseAndResumeRegistrar#register(PausesAndResumes)}.
 *
 * <p>Registered objects will also be subscribed to the {@link com.squareup.otto.OttoBus}
 * only while the activity is running.
 */
public interface PausesAndResumes {
  void onResume();

  void onPause();
}

然后像这样连接起来。 (注意不需要注销。)

private final PauseAndResumeRegistrar pauseAndResumeRegistrar;

@Inject
public Presenter(PauseAndResumeRegistrar pauseAndResumeRegistrar) {
  this.pauseAndResumeRegistrar = pauseAndResumeRegistrar;
}

@Override protected void onEnterScope(MortarScope scope) {
  pauseAndResumeRegistrar.register(scope, this);
}

@Override public void onResume() {
}

@Override public void onPause() {
}

这是 Activity 注入(inject)的演示者，以使其全部工作。

/**
 * Presenter to be registered by the {@link PauseAndResumeActivity}.
 */
public class PauseAndResumePresenter extends Presenter<PauseAndResumeActivity>
    implements PauseAndResumeRegistrar {

  private final Set<Registration> registrations = new HashSet<>();

  PauseAndResumePresenter() {
  }

  @Override protected MortarScope extractScope(PauseAndResumeActivity view) {
    return view.getMortarScope();
  }

  @Override public void onExitScope() {
    registrations.clear();
  }

  @Override public void register(MortarScope scope, PausesAndResumes listener) {
    Registration registration = new Registration(listener);
    scope.register(registration);

    boolean added = registrations.add(registration);
    if (added && isRunning()) {
      listener.onResume();
    }
  }

  @Override public boolean isRunning() {
    return getView() != null && getView().isRunning();
  }

  public void activityPaused() {
    for (Registration registration : registrations) {
      registration.registrant.onPause();
    }
  }

  public void activityResumed() {
    for (Registration registration : registrations) {
      registration.registrant.onResume();
    }
  }

  private class Registration implements Scoped {
    final PausesAndResumes registrant;

    private Registration(PausesAndResumes registrant) {
      this.registrant = registrant;
    }

    @Override public void onEnterScope(MortarScope scope) {
    }

    @Override public void onExitScope() {
      registrations.remove(this);
    }

    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;

      Registration that = (Registration) o;

      return registrant.equals(that.registrant);
    }

    @Override
    public int hashCode() {
      return registrant.hashCode();
    }
  }
}