CreateCaptureSession.kt

private fun createCameraPreviewSessionFront() {
  try {
    val texture = textureViewFront.surfaceTexture

    texture.setDefaultBufferSize(previewSizeFront.width, previewSizeFront.height)
    val surface = Surface(texture)
    previewRequestBuilderFront = cameraDeviceFront!!.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW)
    previewRequestBuilderFront.addTarget(surface)

    // Here, we create a CameraCaptureSession for camera preview.
    cameraDeviceFront?.createCaptureSession(Arrays.asList(surface, imageReaderFront?.surface), object : CameraCaptureSession.StateCallback() {
      override fun onConfigured(cameraCaptureSession: CameraCaptureSession) {
                        // The camera is already closed
        if (cameraDeviceFront == null) return
        // When the session is ready, we start displaying the preview.
        captureSessionFront = cameraCaptureSession
        try {
          // Auto focus should be continuous for camera preview.
          previewRequestBuilderFront.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE)
          // Finally, we start displaying the camera preview.
          previewRequestFront = previewRequestBuilderFront.build()
          captureSessionFront?.setRepeatingRequest(previewRequestFront, captureCallback, backgroundHandler)
        } catch (e: CameraAccessException) {
          Log.e(TAG, e.toString())
        }
      }
      override fun onConfigureFailed(session: CameraCaptureSession) {
      }
    }, null)
  } catch (e: CameraAccessException) {
    Log.e(TAG, e.toString())
  }
}