DashboardFragment.kt

class DashboardFragment : Fragment() {
  
  companion object {
    const val CLIENT_ID = "xxxxx"
    const val REDIRECT_URI = "asoview://www.example.com/oauth2redirect/"
  }
 
  private var _authService: AuthorizationService? = null
  private var _authState: AuthState? = null

  // 省略
  
  override fun onCreateView(
      inflater: LayoutInflater,
      container: ViewGroup?,
      savedInstanceState: Bundle?
  ): View {

    // 省略

    // AppAuth設定
    val serviceConfig = AuthorizationServiceConfiguration(
      Uri.parse("https://www.example.com/app/v1/authorization"),  // authorization endpoint
      Uri.parse("https://www.example.com/app/v1/token") // token endpoint
      )
    _authState = AuthState(serviceConfig)
    _authService = AuthorizationService(requireContext())

      // 省略
      
    return ComposeView(requireContext()).apply {
      setViewCompositionStrategy(ViewCompositionStrategy.DisposeOnViewTreeLifecycleDestroyed)
      setContent {
          DashboardCompose()
      }
    }
  }
  
  private fun login() {
    // アプリ内ブラウザでOAuth2の認証を開始する
    // なお、ネイティブアプリ埋め込みのWebViewで認証エンドポイントとやりとりする方法は推奨されていない。（rfc8252の8.12.を参照）
    val authRequest = AuthorizationRequest.Builder(
        _authState!!.authorizationServiceConfiguration!!,
        CLIENT_ID,
        ResponseTypeValues.CODE,
        Uri.parse(REDIRECT_URI)
    ).setScope("openid profile phone email").build()
    val authIntent = _authService!!.getAuthorizationRequestIntent(authRequest)
    activityResult.launch(authIntent)
  }

  @Composable
  private fun DashboardCompose(dashBoadViewModel: DashboardViewModel = viewModel()) {
    Button(onClick = { login() }, modifier = Modifier.wrapContentSize(Alignment.TopStart)) {
        Text("login")
    }
  }
}