WallpaperFragment.kt

private fun setWallpaper() {
    val setIntent = Intent(Intent.ACTION_SET_WALLPAPER)

    if (activity!!.packageManager.resolveActivity(setIntent, PackageManager.MATCH_DEFAULT_ONLY) == null) {
        val dialog = ProgressDialog()
        dialog.isCancelable = false
        dialog.title = getString(R.string.setting_up_wallpaper)
        dialog.show(fragmentManager, "")
        runInBackground {
            WallpaperManager.getInstance(activity).setStream(FileInputStream(imageFile))
            runInMainThread {
                dialog.dismiss()
                toast(R.string.wallpaper_set)
            }
        }
    } else {
        setIntent.action = Intent.ACTION_ATTACH_DATA
        setIntent.addCategory(Intent.CATEGORY_DEFAULT)
        setIntent.data = imageFileUri

        val activities = activity!!.packageManager.queryIntentActivities(setIntent, PackageManager.MATCH_DEFAULT_ONLY)
        for (activity in activities) {
            getActivity()!!.grantUriPermission(activity.activityInfo.packageName, imageFileUri, Intent.FLAG_GRANT_READ_URI_PERMISSION)
        }
        startActivityForResult(Intent.createChooser(setIntent, getString(R.string.set_as)), SETTING_REQUEST_CODE)
    }
}