StateCallback.kt

private val stateCallbackFront = object : CameraDevice.StateCallback() {
  override fun onOpened(cameraDevice: CameraDevice) {
    this@CameraFragment.cameraDeviceFront = cameraDevie
    createCameraPreviewSessionFront()
  }
override fun onDisconnected(cameraDevice: CameraDevice) {
  cameraDevice.close()
  this@CameraFragment.cameraDeviceFront = null
  }
override fun onError(cameraDevice: CameraDevice, error: Int) {
  onDisconnected(cameraDevice)
  this@CameraFragment.activity?.finish()
  }
}