The end of confusion of callback between activity and fragment.

1. The end of
confusion of callback between
activity and fragment.
2014-02-12
potatotips #4 Toshihiro Yagi

2. About me
Twitter : @sys1yagi
Blog : http://sys1yagi.com
!
!
Android Engineer at

3. 出てます。
http://www.amazon.co.jp/gp/product/4798040029/

4. Problem
•
How communicate between Activity and Fragment?
?
Activity
Fragment

5. #01 Implement a interface in a Activity
Implements Interface
Declare Interface
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallback = (Listener) activity;
} catch (ClassCastException e) {
throw new
ClassCastException(activity.toString()
+ " must implement Listener");
}
}
Communicating with Other Fragments
http://developer.android.com/training/basics/fragments/communicating.html

6. mCallback = (Listener) activity;
throw new
いいんだけどダサくね？
try{}catch{}
ClassCastExcep
ends Activity implements Listener{

7. #02 No rotation or receive config changes.
Declare Interface
No rotation
Set Interface

8. でも結局Activity破棄再生成で死ぬよね？

9. #03 Using message bus.
Message Bus
Otto
!
@Override
protected void onCreate(Bundle save) {
super.onCreate(savedInstanceState);
bus.register(this);
}
@Subscribe
private void onClick(OnClickEvent event){
//do something
}
bus.post(new OnClickEvent(10));
Otto
http://square.github.io/otto/

10. 濫用するときつい
コンテキスト遠い

11. #04 Using Roboguice or Dagger, etc…
Injector
Module
Depend on
Declare Interface

12. OK
but, exaggerated

13. In the first place…
•
なんでActivity-Fragment間連携の為に色々な罠を
かいくぐらなければならないんだ
•
ついでにDialogFragment-Fragment間もだるい
•
再生成を別々にするのがそもそもおかしくね？
•
基本的にActivity←Fragmentの一方向依存だよね
•
統一的で簡単で罠のない書き方がほしい

14. 無かったら作る

15. indirect injector

16. Simplify
Indirect Injector
Declare Interface
add dependency
inject request

17. Simplify
Indirect Injector
Declare Interface
add dependency
inject request
@Override
protected void onCreate(Bundle save) {
super.onCreate(savedInstanceState);
IndirectInjector.addDependency(this, mListener);
}
@Inject
Listener mListener;
!
@Override
public void onActivityCreated(Bundle savedInstanceState) {
IndirectInjector.inject(getActivity(), this);
}

18. Good bye confusion
•
build.gradleにdependencies書いて
•
Fragmentの必要なフィールドに@Injectつけて
•
Activity側でIndirectInjectorにaddDependency()する
•
FragmentのonActivityCreated()でIndirectInjectorの
inject()を呼ぶ
•
どういう再生成が走っても大丈夫

19. Enjoy!

20. おわりに
https://github.com/sys1yagi/indirect-injector
Welcome your pull request!
GitHub活動を通して個人のキャリアを積みつつ仕事の成果を出したい

21. We are hiring!!!