WallpaperFragment.kt

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)
    contentView = pv_wallpaper

    if (model.state != PROGRESS && imageFile.exists()) {
        loadFileToImageView()
    } else {
        checkData()
    }
}

private fun checkData() {
    if (view == null) return

    when (model.state) {
        CREATED -> {
            showProgress()
            model.setListener { checkData() }
            model.load(relativeUrl, imageFile)
        }

        PROGRESS -> {
            showProgress()
            model.setListener { checkData() }
        }

        LOADED -> loadFileToImageView()

        ERROR -> {
            showError(R.string.unable_to_load) {
                showProgress()
                model.setListener { checkData() }
                model.load(relativeUrl, imageFile)
            }
        }
    }
}

private fun loadFileToImageView() {
    showContent()
    GlideApp.with(context!!)
            .load(Uri.fromFile(imageFile))
            .transition(DrawableTransitionOptions.withCrossFade())
            .into(pv_wallpaper)
    loaded = true
}