使用投影上下文访问音频眼镜和显示眼镜上的硬件

@RequiresApi(Build.VERSION_CODES.BAKLAVA)
@OptIn(ExperimentalProjectedApi::class, ExperimentalCoroutinesApi::class)
private fun monitorProjectedConnectivity(activity: ComponentActivity) {
    activity.lifecycleScope.launch {
        // Before creating a projected context, check to see if the projected device is connected.
        // While this method returns true, the projected context remains valid.
        ProjectedContext.isProjectedDeviceConnected(activity, coroutineContext)
            .collectLatest { isConnected ->
                if (isConnected) {
                    // From a phone Activity or Service, get a context for the audio and display glasses.
                    // Re-initialize on reconnect: Obtain another context instance.
                    val projectedContext = try {
                        ProjectedContext.createProjectedDeviceContext(activity)
                    } catch (e: IllegalStateException) {
                        Log.e(TAG, "Failed to create projected context", e)
                        return@collectLatest
                    }

                    // Use the projectedContext to initialize system services (e.g., CameraManager).
                    Log.i(TAG, "Projected device connected. Initializing hardware...")
                } else {
                    // The projected context is destroyed when the device disconnects.
                    // Clean up on disconnect: Listen for 'false' and release resources.
                    Log.i(TAG, "Projected device disconnected. Cleaning up hardware resources...")
                }
            }
    }
}
ProjectedHardware.kt

// Initialize AudioRecord with projected device context
val audioRecord = AudioRecord.Builder()
    .setAudioSource(MediaRecorder.AudioSource.CAMCORDER)
    .setAudioFormat(audioFormat)
    .setBufferSizeInBytes(bufferSize)
    // pass in the projected device context
    .setContext(projectedDeviceContext)
    .build()

audioRecord.startRecording()
ProjectedHardware.kt

val audioManager = context.getSystemService(AudioManager::class.java) ?: return
val devices = audioManager.getDevices(AudioManager.GET_DEVICES_INPUTS)
val hfpDevice = devices.find { it.type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO }

hfpDevice?.let { device ->
    val audioRecord = AudioRecord.Builder()
        .setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION)
        .setAudioFormat(audioFormat)
        .setBufferSizeInBytes(bufferSize)
        .build()

    // Route recording to the Bluetooth device
    audioRecord.setPreferredDevice(device)
    audioManager.setCommunicationDevice(device)

    audioRecord.startRecording()
ProjectedHardware.kt

private fun startCameraOnGlasses(activity: ComponentActivity) {
    activity.lifecycleScope.launch {
        // Before creating a projected context, check to see if the projected device is connected.
        ProjectedContext.isProjectedDeviceConnected(activity, coroutineContext)
            .collectLatest { isConnected ->
                if (isConnected) {
                    // 1. Get the CameraProvider using the projected context.
                    // When using the projected context, DEFAULT_BACK_CAMERA maps to the audio and display glasses' camera.
                    val projectedContext = try {
                        ProjectedContext.createProjectedDeviceContext(activity)
                    } catch (e: IllegalStateException) {
                        Log.e(TAG, "Projected context could not be created", e)
                        return@collectLatest
                    }

                    val cameraProviderFuture = ProcessCameraProvider.getInstance(projectedContext)

                    cameraProviderFuture.addListener({
                        val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()
                        val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

                        // 2. Check for the presence of a camera.
                        if (!cameraProvider.hasCamera(cameraSelector)) {
                            Log.w(TAG, "The selected camera is not available.")
                            return@addListener
                        }

                        // 3. Query supported streaming resolutions using Camera2 Interop.
                        val cameraInfo = cameraProvider.getCameraInfo(cameraSelector)
                        val camera2CameraInfo = Camera2CameraInfo.from(cameraInfo)
                        val cameraCharacteristics = camera2CameraInfo.getCameraCharacteristic(
                            CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP
                        )

                        // 4. Define the resolution strategy.
                        val targetResolution = Size(1920, 1080)
                        val resolutionStrategy = ResolutionStrategy(
                            targetResolution,
                            ResolutionStrategy.FALLBACK_RULE_CLOSEST_LOWER
                        )
                        val resolutionSelector = ResolutionSelector.Builder()
                            .setResolutionStrategy(resolutionStrategy)
                            .build()

                        // 5. If you have other continuous use cases bound, such as Preview or ImageAnalysis,
                        // you can use  Camera2 Interop's CaptureRequestOptions to set the FPS
                        val fpsRange = Range(30, 60)
                        val captureRequestOptions = CaptureRequestOptions.Builder()
                            .setCaptureRequestOption(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, fpsRange)
                            .build()

                        // 6. Initialize the ImageCapture use case with options.
                        val imageCapture = ImageCapture.Builder()
                            // Optional: Configure resolution, format, etc.
                            .setResolutionSelector(resolutionSelector)
                            .build()

                        try {
                            // Unbind use cases before rebinding.
                            cameraProvider.unbindAll()

                            // Bind use cases to camera using the Activity as the LifecycleOwner.
                            cameraProvider.bindToLifecycle(
                                activity,
                                cameraSelector,
                                imageCapture
                            )
                        } catch (exc: Exception) {
                            Log.e(TAG, "Use case binding failed", exc)
                        }
                    }, ContextCompat.getMainExecutor(activity))
                }
            }
    }
}
ProjectedHardware.kt

@OptIn(ExperimentalProjectedApi::class)
private fun getPhoneContext(activity: ComponentActivity): Context? {
    return try {
        // From a projected Activity, get a context for the phone.
        ProjectedContext.createHostDeviceContext(activity)
    } catch (e: IllegalStateException) {
        Log.e(TAG, "Failed to create host device context", e)
        null
    }
}
ProjectedHardware.kt