Android main activity implementing a Flutter method channel for file sharing

MainActivity.kt

class MainActivity : FlutterActivity() {
    private val SHARE_CHANNEL = "jademind.com/share"

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        GeneratedPluginRegistrant.registerWith(this)

        MethodChannel(flutterView, SHARE_CHANNEL).setMethodCallHandler { call, result ->
            if (call.method.equals("share-file")) {
                val argsMap = call.arguments as HashMap<String, String>

                val subject = argsMap.get("subject")
                val filename = argsMap.get("filename")
                val filepath = argsMap.get("filepath")
                val mimeType = argsMap.get("mimeType")
                val contentUri = Uri.parse(filepath)

                val shareIntent = Intent(Intent.ACTION_SEND)
                shareIntent.setType(mimeType)
                shareIntent.putExtra(Intent.EXTRA_STREAM, contentUri)

                this.startActivity(Intent.createChooser(shareIntent, subject))
            }
        }
    }
}