Android CameraX doesn't show anything

Question

I've implemented a new sample, here is a link which describes new CameraX api from Google codelabs, but TextureView doesn't show anything and throw next exception:

OpenGLRenderer: [SurfaceTexture-0-7609-1] dequeueImage: SurfaceTexture is not attached to a View

Another camera samples as a Camera2 and native camera app work fine I used emulator with api level Q beta 3

class CameraXFragment : Fragment(), TextureView.SurfaceTextureListener {

    companion object {
        fun newInstance(): Fragment = CameraXFragment()
    }

    private val REQUEST_CODE_PERMISSIONS = 10
    private val REQUIRED_PERMISSIONS = arrayOf(Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE)

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? = inflater.inflate(R.layout.fragment_camera, container, false)

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        viewFinder.surfaceTextureListener = this
    }

    private fun startCamera() {
        CameraX.unbindAll()

        val previewConfig = PreviewConfig.Builder().apply {
            setTargetAspectRatio(Rational(1, 1))
            setTargetResolution(Size(320, 320))
        }.build()

        val preview = Preview(previewConfig)
        preview.setOnPreviewOutputUpdateListener {
            viewFinder.surfaceTexture = it.surfaceTexture
            updateTransform()
        }

        val imageCaptureConfig = ImageCaptureConfig.Builder()
                .apply {
                    setTargetAspectRatio(Rational(1, 1))
                    setCaptureMode(ImageCapture.CaptureMode.MIN_LATENCY)
                }.build()

        val imageCapture = ImageCapture(imageCaptureConfig)
        captureButton.setOnClickListener {
            val file = File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), "${System.currentTimeMillis()}.jpg")
            imageCapture.takePicture(file,
                    object : ImageCapture.OnImageSavedListener {
                        override fun onError(error: ImageCapture.UseCaseError, message: String, t: Throwable?) {
                            t?.printStackTrace()
                        }

                        override fun onImageSaved(file: File) {
                            val msg = "Photo capture succeeded: ${file.absolutePath}"
                            Toast.makeText(requireContext(), msg, Toast.LENGTH_SHORT).show()
                        }
                    })
        }

        CameraX.bindToLifecycle(this, preview, imageCapture)
    }

    private fun updateTransform() {
        val matrix = Matrix()
        val centerX = viewFinder.width / 2f
        val centerY = viewFinder.height / 2f
        val rotationDegrees = when (viewFinder.display.rotation) {
            Surface.ROTATION_0 -> 0
            Surface.ROTATION_90 -> 90
            Surface.ROTATION_180 -> 180
            Surface.ROTATION_270 -> 270
            else -> return
        }
        matrix.postRotate(-rotationDegrees.toFloat(), centerX, centerY)
        viewFinder.setTransform(matrix)
    }

    override fun onSurfaceTextureSizeChanged(surface: SurfaceTexture, width: Int, height: Int) {
    }

    override fun onSurfaceTextureUpdated(surface: SurfaceTexture) {
    }

    override fun onSurfaceTextureDestroyed(surface: SurfaceTexture): Boolean {
        return true
    }

    override fun onSurfaceTextureAvailable(surface: SurfaceTexture?, width: Int, height: Int) {
        if (allPermissionsGranted()) {
            viewFinder.post { startCamera() }
        } else {
            requestPermissions(REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS)
        }
        viewFinder.addOnLayoutChangeListener { _, _, _, _, _, _, _, _, _ ->
            updateTransform()
        }
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array, grantResults: IntArray) {
        if (requestCode == REQUEST_CODE_PERMISSIONS) {
            if (allPermissionsGranted()) {
                viewFinder.post { startCamera() }
            } else {
                Toast.makeText(requireContext(), "Permissions are not granted", Toast.LENGTH_SHORT).show()
            }
        }
    }

    private fun allPermissionsGranted(): Boolean {
        for (permission in REQUIRED_PERMISSIONS) {
            if (ContextCompat.checkSelfPermission(requireContext(), permission) != PackageManager.PERMISSION_GRANTED) {
                return false
            }
        }
        return true
    }
}

hey I am getting images rotated to the right did u have that problem?? — Pemba Tamang
That is the bug in the library due to invalid meta data!, only for front lense though! Hope this will fixed with beta! — Himanshu Walia
Is this problem fixed? I'm facing the same issue. when I bind lifecycle to preview it works fine but it's a black screen when binding to imageCapture — Maryam Mirzaie

Oscar Wahltinez Oscar Wahltinez · Accepted Answer · 2019-05-14T00:11:11

The TextureView needs to be removed and re-added from the parent view for the SurfaceTexture to be attached. This is because TextureView internally creates its own SurfaceTexture once it is attached to the view hierarchy, and that internal SurfaceTexture only gets correctly detached once the parent TextureView is removed from the view hierarchy. You should change preview.setOnPreviewOutputUpdateListener to:

preview.setOnPreviewOutputUpdateListener {
    val parent = viewFinder.parent as ViewGroup
    parent.removeView(viewFinder)
    viewFinder.surfaceTexture = it.surfaceTexture
    parent.addView(viewFinder, 0)
    updateTransform()
}

It looks like you may have copied the code from the codelab, which has now been updated to include the view re-attachment. The official sample also implements this view re-attachment.

Android CameraX doesn't show anything

4 Answers