Shinji Furukawa gave a presentation on building Android Wear apps. He explained that Android Wear is the OS for wearable devices like smartwatches that connects to smartphones via Bluetooth. He demonstrated how to create a basic watch face app using the CanvasWatchFaceService with features like drawing hands and setting background images. He also discussed additional capabilities like accessing sensors and coordinating with companion smartphone apps using data transfer. The talk provided an overview of getting started with Android Wear app development and showcased some example project ideas.

1. 1
Build your first
Wear App
2019/02/10 GDG Meetup Kyoto @furusin_oriver

2. Who？
Shinji Furukawa 古川 真次（ふるしん）
@furusin_oriver
furusin
Compamy：FURYU.Inc
Work：Android Engineer
Product：for teenager girls app

3. We were sponsor of DroidKaigi

4. Contributors

5. Contributors

6. Contributors

7. My own wear project
Watch Image Setter（ウォッチ写真セッター）
https://play.google.com/store/apps/details?id=net.furusin.www.SelectedPhotoWatchFace
Set image what you want for WatchFace background.

8. My own wear project
Where is Wear？
to Find Wear I lost with vibration

9. 9
Building WatchFace apps
brief tips
@furusin_oriver

10. Anyone has Android Wears？

11. Anyone has build your Wear Apps？

12. Android Wear？
• What For?
• Android OS for Wearable devices. (Smart Watch)
• Name
• Wear OS by Google（since 3/15/2018）
• Sensors
GPS / Accelerometer / Heart Rate etc...
Connect with SmartPhone with Bluetooth(or WIFI).

13. Android Wear 4.4W（based w/ Android4.4）
Android Wear 1.0（based w/ Android5.1）
:
:
Android Wear 2.0
Wear OS by Google 1.0
Wear OS by Google 2.0
6/24/2014
（Google IO）
15/3/2018
8/2018
History

14. Modes
• Interactive Mode
• Active Mode
• Always-on Mode
• Ambient mode（Sleep Mode）
• Save Battery
• The background color
scheme is limited to
black, white and gray.

15. SDKs
• Accessible to Android SDK
• Support Library
• com.google.android.support:wearable:2.4.0：No AndroidX yet
• minSdkVersion 23
• Wearable UI Support Library
• com.android.support:wear:26.0.0

16. Google sample code
https://github.com/googlesamples/android-WatchFace

17. Getting started Creating Project
Just Enable “Wear OS”

18. Select “Watch Face“
Getting started Creating Project

19. Select Style of WatchFace
• Analog
• Digital
Getting started Creating Project

20. Run Hello,World!
Just start created Project

21. Run Hello,World!
Just start created Project
Background Image

22. Run Hello,World!
Just start created Project
Background Image
Hour Hand

23. Run Hello,World!
Just start created Project
Background Image
Hour Hand
Minute Hand

24. Run Hello,World!
Just start created Project
Background Image
Hour Hand
Minute Hand
Second Hand

25. Run Hello,World!
Just start created Project
Background Image

26. Connect handheld and Virtual Wearable
run
$ adb -d forward tcp:5601 tcp:5601
select `Emulator` to connect
※handheld = Mobile devise
（in Wearable, we call mobile devise “handheld”）

27. Let’s see codes!

28. AndroidManifest.xml

29. Key Class
Engine
CanvasWatchFaceService.Engine()
CanvasWatchFaceService
WatchFaceService
WallpaperService
Service
android.support.wearable.watchface
.WatchFaceService.Engine
android.service.wallpaper
.WallpaperService.Engine
CanvasWatchFaceService Engine

30. implementation
• onCreateEngine()
• must be implemented.
（similar as onCreate with handheld app）
• onTimeTick()
• basicary called every mins
• called date, time or timezone changed as well
• onAmbientModeChanged(Boolean)
• called when enter or exits ambient mode
• onDraw
• draw WatchFace

31. How to set Image to Background？

32. for example...
able to switch background image every seconds.

33. How to draw hands？
set rotate degrees

34. How to draw hands？
set rotate degrees
for second

35. How to draw hands？
set rotate degrees
for second
for minute

36. How to draw hands？
set rotate degrees
for second
for minute
for hour

37. How to draw hands？
set rotate degrees
for second
for minute
for hour
set degrees
drawLine

38. Any idea examples
• Visible hanhold / wear batteries during active mode.
• Check heart late every hour.
• set backgroundImage your child’s photo(I do!)

39. In Addition
• You can build Handheld apps coordinate with Wear
Apps.(called Companion app)
• to transfer datas from handheld to wearable, use
`Asset` class.(Data Object)
• Use Google Play Service API
•CAUTION：GoogleApiClient has DEPRECATED！
• from Google Play Service 11.8.0, GoogleApiCLient should
be migrated to the GoogleApi class.

40. Conclusion
• Very easy to create WatchFace.
• able to connect from Handheld device to Virtual
Wearable device.
• able to access Android SDKs.
• able to access any Sensors.

41. Conclusion
• Very easy to create WatchFace.
• able to connect from Handheld device to Virtual
Wearable device.
• able to access Android SDKs.
• able to access any Sensors.
• Enjoy Android Wear！

42. Extra

43. We are Hiring!
• We desire Android Engineer!
• Talk into me, please!

44. Next Event
京都Devかふぇ#5 〜Android Event 2019 リジェクトコン〜
Reject Conference of DroidKaigi（UnOfficial）
2019/03/01(Fri) 19:00〜