XMLActivity.kt

fun Context.openSystemViewerForSAFUri(uri: Uri?) {
    uri?:return
    val mimeType1 = FileInfo.fromSAFUri(this,uri)?.mimeType
    val extension = MimeTypeMap.getFileExtensionFromUrl(uri.toString())
    val mimeType2 =  MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.lowercase())
    val mimeType3 = "*/*"
    val intent = Intent(Intent.ACTION_VIEW).apply {
        setDataAndType(uri, mimeType1?:mimeType2?:mimeType3)
        addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
    }
    try {
        startActivity(intent)
    } catch (e: ActivityNotFoundException) {
        Toast.makeText(this, "No app found to open this file type", Toast.LENGTH_SHORT).show()
    }
}