SimplePreviewActivity.kt

private val textureView: TextureView by lazy {
    findViewById<TextureView>(R.id.texture_view)
}

override fun onResume() {
    super.onResume()

    if (textureView.isAvailable) {
        openCamera()
    } else {
        textureView.surfaceTextureListener = object : TextureView.SurfaceTextureListener {
            override fun onSurfaceTextureAvailable(texture: SurfaceTexture?, p1: Int, p2: Int) {
                openCamera()
            }

            override fun onSurfaceTextureSizeChanged(texture: SurfaceTexture?, p1: Int, p2: Int) {}
            override fun onSurfaceTextureUpdated(texture: SurfaceTexture?) {}
            override fun onSurfaceTextureDestroyed(texture: SurfaceTexture?): Boolean = true
        }
    }
}