AccountManager.blockingGetAuthToken() does not prompt for credentials

Question

I use a SyncAdapter and an AccountAuthenticator in my app. When doing the sync stuff, I call AccountManager.blockingGetAuthToken to get an access token. I understand this method that way, that it starts my Log-in activity when it can not get a token (or in other words, when the getAuthToken methods returns an Intent to start the Activity). But it just returns null, without launching the Activity.

This is the getAuthToken method from my authenticator.

@Override
    public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {

        // Extract the username and password from the Account Manager, and ask
        // the server for an appropriate AuthToken.
        final AccountManager am = AccountManager.get(mContext);

        String authToken = am.peekAuthToken(account, authTokenType);

        // Lets give another try to authenticate the user
        if (TextUtils.isEmpty(authToken)) {
            final String password = am.getPassword(account);
            if (password != null) {
                try {
                    authToken = APIHelper.getInstance().logIn(account.name, password);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        // If we get an authToken - we return it
        if (!TextUtils.isEmpty(authToken)) {
                    // cache
            am.setAuthToken(account, authTokenType, authToken);
            final Bundle result = new Bundle();
            result.putString(AccountManager.KEY_ACCOUNT_NAME, account.name);
            result.putString(AccountManager.KEY_ACCOUNT_TYPE, account.type);
            result.putString(AccountManager.KEY_AUTHTOKEN, authToken);
            return result;
        }

        // If we get here, then we couldn't access the user's password - so we
        // need to re-prompt them for their credentials. We do that by creating
        // an intent to display our AuthenticatorActivity.
        final Intent intent = new Intent(mContext, AuthActivity.class);
        intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
        intent.putExtra(AuthActivity.ARG_ACCOUNT_TYPE, account.type);
        intent.putExtra(AuthActivity.ARG_AUTH_TYPE, authTokenType);
        final Bundle bundle = new Bundle();
        bundle.putParcelable(AccountManager.KEY_INTENT, intent);
        return bundle;
    }

By the way, most of the code is from this blog.

Answer 1

It seems the asker figured it out. For posterity, it works if you use this instead:

AccountManagerFuture<Bundle> resultFuture = accountManager.getAuthToken(
        account,
        AUTH_TOKEN_TYPE,
        null,
        activity,
        null,
        null
);
Bundle bundle = resultFuture.getResult();
return bundle.getString(AccountManager.KEY_AUTHTOKEN);

I guess blockingGetAuthToken() is unable to do this automatically because it lacks the activity parameter. And the documentation is incorrect.