sample-app-guide

作者: facebook

Building a complete DAT app with session creation, camera streaming, and photo capture

npx skills add https://github.com/facebook/meta-wearables-dat-android --skill sample-app-guide

Sample App Guide (Android)

Build an Android DAT app with registration, sessions, camera streaming, and photo capture.

Pair this with the CameraAccess sample.

Project setup

  1. Create an Android Studio app project.
  2. Add the DAT Maven repository and dependencies.
  3. Configure AndroidManifest.xml for registration callbacks plus APPLICATION_ID and CLIENT_TOKEN.
  4. Initialize Wearables in your Application.

Suggested app structure

app/src/main/java/com/example/myapp/
├── MyApplication.kt
├── MainActivity.kt
├── session/
│   └── SessionViewModel.kt
└── ui/
    ├── RegistrationScreen.kt
    └── CameraScreen.kt

Registration and session creation

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        lifecycleScope.launch {
            Wearables.registrationState.collect { state ->
                // Update registration UI
            }
        }
    }

    fun register() {
        Wearables.startRegistration(this)
    }
}
class SessionViewModel : ViewModel() {
    private var session: Session? = null
    private var camera: Camera? = null

    fun startCameraSession() {
        val createdSession = Wearables.createSession(AutoDeviceSelector()).getOrElse { error ->
            throw IllegalStateException(error.description)
        }
        createdSession.start()
        session = createdSession

        camera = createdSession.addCamera(
            StreamConfiguration(videoQuality = VideoQuality.MEDIUM, frameRate = 24),
        ).getOrElse { error ->
            throw IllegalStateException(error.description)
        }.also { addedCamera ->
            addedCamera.stream.start().getOrElse { error ->
                throw IllegalStateException(error.description)
            }
        }
    }
}

Observe frames and capture photos

viewModelScope.launch {
    camera?.stream?.videoStream?.collect { frame ->
        // Render preview
    }
}

fun capturePhoto() {
    viewModelScope.launch {
        camera?.stream?.capturePhoto()
            ?.onSuccess { photoData ->
                savePhoto(photoData.data)
            }
            ?.onFailure { error, _ ->
                showCaptureError(error.description)
            }
    }
}

Shutdown

fun stopCameraSession() {
    camera?.stop()
    session?.stop()
    camera = null
    session = null
}

Testing with MockDeviceKit

Use MockDeviceKit to simulate linking glasses, permission state, and camera media without physical hardware. See MockDevice Testing for setup details.

Links