GKAC 2015 Apr. - Android Looper
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Speaker: 차영호 GDG Korea Android Conference 2015 Apr. Google Campus Seoul 2015. 4. 18
GKAC 2015 Apr. - Android Looper
- 2. 발표자 소개
- 3. Agenda ● Java VS Android ● Where is main? ● Event Loop ● Create and Handle Event with Message ● Advanced Topic
- 4. Android Looper ● Event Loop for Android ● 공기 같은 존재 ○ 어디에나 있지만, 여간해선 사용할 일은 없다. ○ 사용할 일은 없지만, 모르면 가끔씩 해결이 곤란할 때 가 생긴다.
- 6. Start Entry public class Hello { public static void main(String[] s) { System.out.println("Hello, World"); } } public class HelloActivity extends Activity { @Override public void onCreate(Bundle bundle) { super.onCreate(bundle); setContentView(R.layout.activity_hello); } }
- 7. Start Entry C: > java Hello Hello, World ????
- 8. 간단한 호출경로 확인 방법(Log)
- 9. 간단한 호출경로 확인 방법(Log)
- 10. main() package android.app; public final class ActivityThread { public static void main(String[] args) { // blahblah Looper.loop(); throw new RuntimeException("Main thread loop unexpectedly exited"); } }
- 11. Event Loop while (true) { // do someting }
- 12. Event Loop while (true) { msg = waitAndGetMessage(); handler = msg.getTarget(); handler.handleMessage(msg); }
- 13. 간단한 호출경로 확인 방법(Log)
- 14. Message Queue Image Source: MSDN
- 15. Message Queue Image Source: MSDN
- 16. ANR이 반겨줍니다.
- 17. Events ● Component Lifecycle Event ○ Activity ○ Service ● Intent Handler ○ BroadcastReceiver.onReceive ● View layout & draw ● Input Event
- 18. Event Loop ● android.os.Message ● android.os.Handler ● android.os.Looper ○ android.os.HandlerThread
- 19. Message @Override public void onClick(View v) { setText("Text 1"); } private static final int MSG_HANDLE_CHANGE_TEXT = 1; public void setText(String text) { // Message msg = new Message(); // bad usage Message msg = mHandler.obtainMessage(MSG_HANDLE_CHANGE_TEXT, text); mHandler.sendMessage(msg); }
- 20. Handler private mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case MSG_HANDLE_TEXT_CHANGED: mTextView.setText((String)(msg.obj)); break; default: break; } } }
- 22. 직구를 배웠습니다
- 23. 변화구도 배워봅시다 Image Source: https://mirror.enha.kr/wiki/야구의 구종
- 24. Message Queue Image Source: MSDN sendMessageAtFrontOfQueue()
- 25. Message Queue Image Source: MSDN removeMessages()
- 26. Message Queue Image Source: MSDN sendMessageDelayed() sendMessageAtTime()
- 27. Requirement ● 안드로이드앱이 시작하고나서 1분 후에 팝업을 띄워주세요.
- 28. Solution
- 29. Advanced Topic ● Wakelock ● AlarmManager
- 30. Wakelock ● View.setKeepScreenOn() ● WakeLock ○ FULL_WAKE_LOCK ○ SCREEN_BRIGHT_WAKE_LOCK ○ SCREEN_DIM_WAKE_LOCK ○ PARTIAL_WAKE_LOCK
- 31. AlarmManager ● ELAPSED_REALTIME ● ELAPSED_REALTIME_WAKEUP ● RTC ● RTC_WAKEUP
- 32. Q&A