Learn hints, tips and tricks from the Twitter Fabric development team, and the principles that guided their creation of this modular and powerful SDK. Presentation delivered at DroidconNL, Amsterdam, Nov 2014 Thanks to Andrea Falcone and the Fabric team for content and materials. You can see a lightning version of this talk delivered at Twitter Flight here -> https://www.youtube.com/watch?v=3h7jQU1AOvw&index=2&list=PLFKjcMIU2WsjUiy7UcPiWNxktpin0WDgu

1. Building Twitter’s SDKs
for Android
#droidconnl

2. Andy Piper
Developer Advocate
@andypiper

6. Identity
Stability
Distribution
Revenue

8. .io

9. Powerful
Lightweight

10. Powerful

11. Ease of
Integration

13. Ease of Integration
Fabric.with(this, new Crashlytics());

14. Extensible

15. Extensible
Crashlytics.start(this);

16. Extensible
Crashlytics.start(this, 5);
Crashlytics.setListener(createCrashlyticsListener());
Crashlytics.setPinningInfo(createPinningInfoProvider())
Crashlytics.getInstance().setDebugMode(true);

17. Extensible
Crashlytics.setListener(createCrashlyticsListener());
Crashlytics.setPinningInfo(createPinningInfoProvider());
Crashlytics.getInstance().setDebugMode(true);
Crashlytics.start(this, 5);

18. Extensible
Crashlytics.start(this, delay, listener, pinningInfo,
debugMode);

19. Extensible
Crashlytics.start(this, 0, null, null, null, true);

20. Fluent Pattern
Crashlytics crashlytics = new Crashlytics.Builder()
.delay(1)
.listener(createCrashlyticsListener())
.pinningInfo(createPinningInfoProvider())
.build();
Fabric.with(this, crashlytics);

21. Fluent Pattern
Fabric.with(this, new Fabric.Builder(this)
.kits(new Crashlytics())
.debuggable(true)
.logger(new DefaultLogger(Log.VERBOSE))
.looper(getCustomLooper())
.executor(getCustomExecutorService())
.build());

22. Gracefully
Degrade

23. Gracefully Degrade
if (TextUtils.isEmpty(apiKey)
if (debuggable){
throw new IllegalArgumentException(
“apiKey is null!");
} else {
return null;
}
}

24. Minimizing
Permissions

25. Minimizing Permissions

26. Minimizing Permissions
<uses-permission android:name="android.permission.INTERNET"/>

27. Minimizing Permissions
Crashlytics.setUserEmail(“appuser@domain.com”);

28. Permissions:
Runtime Detection
protected boolean canCheckNetworkState() {
String permission =
“android.permission.ACCESS_NETWORK_STATE”;
int result =
context.checkCallingOrSelfPermission(permission);
return (result == PackageManager.PERMISSION_GRANTED);
}

29. Multiple
Application
Types

30. Multiple Application Types
package com.example;
import android.app.Service;
public class MyService
extends Service {
}

31. UI from Application Context
private WeakReference<Activity> currentActivity = new
WeakReference<Activity>();
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
private void registerLifecycleCallbacks() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO) {
final Application app = ((Application)context);
app.registerActivityLifecycleCallbacks(
new ActivityLifecycleCallbacks() {
@Override
public void onActivityResumed(Activity activity) {
currentActivity.set(activity);
}
});
}
}

32. Powerful SDKs
Ease of Integration
Extensibility
Support all app types
Permission detection

33. Lightweight

34. Binary Size

35. Binary Size

36. 3rd Party
Library
Mindfulness

37. 3rd Party
Library Mindfulness
30
20
10
0

38. 3rd Party Library Mindfulness
PROTOBUF
KB
OURS
KB

39. Dalvik
Method
Count

40. Dalvik Method Count
>./gradlew assemble
…
Unable to execute dex: method ID not in [0,
0xffff]: 65536
Conversion to Dalvik format failed: Unable to
execute dex: method ID not in [0, 0xffff]: 65536

41. Dalvik Method Count
> git clone git@github.com:mihaip/dex-method-counts.git
> cd dex-method-counts
> ant jar
> ./dex-method-counts path/to/App.apk
Read in 65490 method IDs.
<root>: 65490
: 3
accessibilityservice: 6
bluetooth: 2
content: 248
pm: 22
res: 45
...
com: 53881
adjust: 283
sdk: 283

42. Minimize
Network
Usage

43. Network Usage
10X SMALLER
XML PROTOBUF
100X FASTER

44. Reduce
Startup
Time

45. Startup Time
Thread.start();
Executors.newSingleThreadExecutor();

46. Startup Time
class MyThreadFactory implements ThreadFactory {
@Override
public Thread newThread(Runnable runnable) {
final Thread thread = new Thread(runnable);
thread.setPriority(Process.THREAD_PRIORITY_BACKGROUND);
return thread;
}
}

47. Lightweight SDKs
Binary size
3rd party library mindfulness
Dalvik Method Count
Network usage
Startup time

48. Lightweight
Powerful

50. Cannonball
github.com/twitterdev

51. Thank You
@andypiper
@TwitterDev

52. Thanks to Andrea Falcone
@asfalcone and the
@Fabric team for content
and original materials