/iosMain/Camera.ios.kt

Camera.ios.kt

@OptIn(ExperimentalForeignApi::class)
@Composable
actual fun CameraView(callback: CameraCallback) {
    val session = AVCaptureSession()
    session.sessionPreset = AVCaptureSessionPresetPhoto
    val output = AVCaptureStillImageOutput().apply {
        outputSettings = mapOf(AVVideoCodecKey to platform.AVFoundation.AVVideoCodecJPEG)
    }
    session.addOutput(output)
    val cameraPreviewLayer = AVCaptureVideoPreviewLayer(session = session)
    LaunchedEffect(Unit) {
        val backCamera =
            AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo).firstOrNull { device ->
                (device as AVCaptureDevice).position == AVCaptureDevicePositionBack
            } as? AVCaptureDevice ?: return@LaunchedEffect

        val frontCamera =
            AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo).firstOrNull { device ->
                (device as AVCaptureDevice).position == AVCaptureDevicePositionFront
            } as? AVCaptureDevice ?: return@LaunchedEffect

        var currentCamera = backCamera
        var currentInput =
            AVCaptureDeviceInput.deviceInputWithDevice(currentCamera, null) as AVCaptureDeviceInput
        session.addInput(currentInput)
        session.addOutput(output)
        session.startRunning()

        callback.eventFlow.collect {
            when (it) {
                CameraEvent.CaptureImage -> {
                    val connection = output.connectionWithMediaType(AVMediaTypeVideo)
                    if (connection != null) {
                        output.captureStillImageAsynchronouslyFromConnection(connection) { sampleBuffer, error ->
                            if (sampleBuffer != null && error == null) {
                                val imageData =
                                    AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(
                                        sampleBuffer
                                    )
                                if (imageData != null) {
                                    val filePath =
                                        platform.Foundation.NSTemporaryDirectory() + UIDevice.currentDevice.identifierForVendor?.UUIDString + ".jpg"
                                    imageData.writeToFile(filePath, true)
                                    callback.onCaptureImage(Path(filePath))
                                }
                            }
                        }
                    }
                }

                CameraEvent.SwitchCamera -> {
                    session.stopRunning()
                    session.removeInput(currentInput)
                    currentCamera = if (currentCamera == backCamera) frontCamera else backCamera
                    currentInput = AVCaptureDeviceInput.deviceInputWithDevice(
                        currentCamera,
                        null
                    ) as AVCaptureDeviceInput
                    session.addInput(currentInput)
                    session.startRunning()
                }
            }
        }
    }

    UIKitView(
        modifier = Modifier.fillMaxSize(),
        background = Color.Black,
        factory = {
            val container = UIView()
            container.layer.addSublayer(cameraPreviewLayer)
            cameraPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
            container
        },
        onResize = { container: UIView, rect: CValue<CGRect> ->
            CATransaction.begin()
            CATransaction.setValue(true, kCATransactionDisableActions)
            container.layer.setFrame(rect)
            cameraPreviewLayer.setFrame(rect)
            CATransaction.commit()
        })
}