detecting the deletion of an android account - android

i'm developing an android application with accounts, sync and content provider. adding an account works, syncing also and some data is saved in the content provider.
now, when the user deletes the account using the settings, syncing stops, but the data stays in the content provider.
i'd like to delete it, but i don't know how to catch the event of account deletion.
There is AccountManager.addOnAccountsUpdatedListener(), i've tried to add it to the sync service, but the sync service is started only for the sync and then stopped. so whenever the account gets deleted while there is no sync, it can't get caught.
is there a best practice on how to handle private data when an account gets deleted?

First You should add OnAccountsUpdateListener to you AccountManager using this command:
AccountManager mAccountMgr = AccountManager.get(getContext());
mAccountMgr.addOnAccountsUpdatedListener(new AccountsUpdateListener(), null, false);
AccountsUpdateListener is implemented class of OnAccountsUpdateListener like this:
private class AccountsUpdateListener implements OnAccountsUpdateListener {
#Override
public void onAccountsUpdated(Account[] accounts) {
Account newAccount = null;
for (final Account account : accounts) {
if (account.type.equals(mAccountType)) {
newAccount = account;
}
}
if (newAccount == null) {
// account removed, now you can handle your private data and remove anything you want here
}
}
}
onAccountsUpdated fired when you add an account or an account removed. so you can check your account type to find specified account in accounts array. if it doesn't exist it removed !
mAccountType is your account type. e.g mAccountType = "your application name"

You should use method getAccountRemovalAllowed from your AbstactAccountAuthenticator:
class AccountAuthenticatorImpl(context: Context) : AbstractAccountAuthenticator(context) {
override fun getAccountRemovalAllowed(
response: AccountAuthenticatorResponse?,
account: Account?
): Bundle {
val result = super.getAccountRemovalAllowed(response, account)
val canDelete = result.getBoolean(android.accounts.AccountManager.KEY_BOOLEAN_RESULT, false)
if (canDelete) {
// TODO: account was deleted, so react on it
accountRepository.onAccountDeletedInSystem()
}
return result
}
}

Related

Check if user is authenticated for the first time with Firebase phone Authentication in Android

I need to detect and differentiate two users using Firebase phone authentication. This should be done before granting a privilege to enter into the home activity of the app. When I did as suggested here (Stackoverflow), it does well by detecting the user using timeStamp() method. The answer does its job but the fancy thing is I need some data input from the new user before the verification code is sent.
In order for a verification code to be sent, a user provides a number which is directly authenticated in the firebase. Hence I cannot check if it's a new user (phone number) or current user (phone number).
Here is the code using TimeStamp() method.
private void signInWithPhoneAuthCredential(PhoneAuthCredential credential)
{
_firebaseAuth.signInWithCredential(credential).addOnCompleteListener(Objects.requireNonNull(getActivity()), task ->
{
if(task.isSuccessful())
{
//Sign in success, update UI with the signed-in user's information.
FirebaseUser _user = Objects.requireNonNull(task.getResult()).getUser();
long creationTimestamp = Objects.requireNonNull(Objects.requireNonNull(_user).getMetadata()).getCreationTimestamp();
long lastLoginTimestamp = Objects.requireNonNull(Objects.requireNonNull(_user).getMetadata()).getLastSignInTimestamp();
if(creationTimestamp == lastLoginTimestamp)
{
//Create a new user with account
setUserDataToDatabase(_user, _username, _university, _course, _year);
sendUserToWelcome();
}
else
{
//User exists, just login
sendUserToHome();
}
}
else
{
FancyToast.makeText(getContext(), "Enter sent code", FancyToast.LENGTH_SHORT, FancyToast.INFO, false).show();
}
});
}
After several research with no success. I decided to walk around, I'm using firestore database. I decided to track every user's number in a new collection with auto-generated document id. I called the collection USERS whereas each document has a unique random id.
I get the user's number and check it if any of the registered user has that number with the USERS's collection using a whereEqualTo() method with the phone_number field. If the number is exists I login the user else display a registration screen.
_firestore.collection(USERS).whereEqualTo("phone_number", _phoneCheck).get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>()
{
#Override
public void onComplete(#NonNull Task<QuerySnapshot> task)
{
if(task.isSuccessful())
{
//If task is greater than 0 means there is a presence of a phone number.
if(Objects.requireNonNull(task.getResult()).size() > 0)
{
//Here I allow user to login as usual.
PhoneAuthOptions options = PhoneAuthOptions.newBuilder(_firebaseAuth).setPhoneNumber(_phone).setTimeout(60L, TimeUnit.SECONDS).setActivity(Objects.requireNonNull(getActivity())).setCallbacks(_callbacks).build();
PhoneAuthProvider.verifyPhoneNumber(options);
}
}
else
{
//Else the task is empty means there is no a presence of a phone number.
//Check if there is a presence of registration data to bind with new user.
if(_registrationData != null)
{
//I login user with the new data and save the information into the firestore plus the phone number.
PhoneAuthOptions options = PhoneAuthOptions.newBuilder(_firebaseAuth).setPhoneNumber(_phone).setTimeout(60L, TimeUnit.SECONDS).setActivity(Objects.requireNonNull(getActivity())).setCallbacks(_callbacks).build();
PhoneAuthProvider.verifyPhoneNumber(options);
userInputs();
}
else
{
//Display a welcome a screen to register an account.
FancyToast.makeText(getContext(), "Welcome! Open an account", FancyToast.LENGTH_SHORT, FancyToast.INFO, false).show();
}
}
}
}
});
Allowing unauthenticated user to have a privilege into the database is very risk. Hence, I implemented a rule to allow unauthenticated user to read only.
match /USERS/{document=**}
{
allow read: if true;
}
Though this still is risky, any rule suggestions I will be grad and appreciable.

Firebase Cloud Messaging - Handling logout

How do I handle situation, when user logs out of my application and I no longer want him to receive notifications to the device.
I tried
FirebaseInstanceId.getInstance().deleteToken(FirebaseInstanceId.getInstance().getId(), FirebaseMessaging.INSTANCE_ID_SCOPE)
But I still receive the notifications to my device's registration_id.
I also made sure that this is the token I should delete:
FirebaseInstanceId.getInstance().getToken(FirebaseInstanceId.getInstance().getId(), FirebaseMessaging.INSTANCE_ID_SCOPE)
or simply FirebaseInstanceId.getInstance().getToken()).
I also tried FirebaseInstanceId.getInstance().deleteInstanceId(), but then the next time I call FirebaseInstanceId.getInstance.getToken I receive null (it works on the second try).
I guess, after deleteInstanceId I could immediately call getToken() again, but it looks like a hack. And also there's this answer which states that it shouldn't be done, but it proposes deleting the token which apparently doesn't work.
So what is the right method to handle this?
Okay. So I managed to do some testing and have concluded the following:
deleteToken() is the counterpart of getToken(String, String), but not for getToken().
It only works if the Sender ID you are passing is a different Sender ID (not the same ID that can be seen in your google-services.json). For example, you want to allow a different Server to send to your app, you call getToken("THEIR_SENDER_ID", "FCM") to give them authorization to send to your app. This will return a different registration token that corresponds only to that specific sender.
In the future, if you chose to remove their authorization to send to your app, you'll then have to make use of deleteToken("THEIR_SENDER_ID", "FCM"). This will invalidate the corresponding token, and when the Sender attempts to send a message, as the intended behavior, they will receive a NotRegistered error.
In order to delete the token for your own Sender, the correct handling is to use deleteInstanceId().
Special mentioning this answer by #Prince, specifically the code sample for helping me with this.
As #MichałK already doing in his post, after calling the deleteInstanceId(), getToken() should be called in order to send a request for a new token. However, you don't have to call it the second time. So long as onTokenRefresh() onNewToken() is implemented, it should automatically trigger providing you the new token.
For short, deleteInstanceId() > getToken() > check onTokenRefresh() onNewToken().
Note: Calling deleteInstanceId() will not only delete the token for your own app. It will delete all topic subscriptions and all other tokens associated with the app instance.
Are you positive you're calling deleteToken() properly? The value for audience should be (also seen from my answer that you linked) is "set to the app server's sender ID". You're passing the getId() value which is not the same as the Sender ID (it contains the app instance id value). Also, how are you sending the message (App Server or Notifications Console)?
getToken() and getToken(String, String) returns different tokens. See my answer here.
I also tried FirebaseInstanceId.getInstance().deleteInstanceId(), but then the next time I call FirebaseInstanceId.getInstance.getToken I receive null (it works on the second try).
It's probably because the first time you're calling the getToken(), it's still being generated. It's just the intended behavior.
I guess, after deleteInstanceId I could immediately call getToken() again, but it looks like a hack.
Not really. It's how you'll get the new generated (provided that it is already generated) token. So I think it's fine.
I did a brief research on what would be the most elegant solution to get back the full control (subscribe and unsubscribe to FCM) as before. Enable and disable the FCM after the user logged in or out.
Step 1. - Prevent auto initialization
Firebase now handle the InstanceID and everything else which need to generate a registration token. First of all you need to prevent auto initialization. Based on the official set-up documentation you need to add these meta-data values to your AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<application>
<!-- FCM: Disable auto-init -->
<meta-data android:name="firebase_messaging_auto_init_enabled"
android:value="false" />
<meta-data android:name="firebase_analytics_collection_enabled"
android:value="false" />
<!-- FCM: Receive token and messages -->
<service android:name=".FCMService">
<intent-filter>
<action android:name="com.google.firebase.MESSAGING_EVENT"/>
</intent-filter>
</service>
</application>
Now you disabled the automatic token request process. At the same time you have an option to enable it again at runtime by code.
Step 2. - Implement enableFCM() and disableFCM() functions
If you enable the auto initialization again then you received a new token immediately, so this is a perfect way to implement the enableFCM() method.
All subscribe information assigned to InstanceID, so when you delete it then initiate to unsubscribe all topic. On this way you able to implement disableFCM() method, just turn back off auto-init before you delete it.
public class FCMHandler {
public void enableFCM(){
// Enable FCM via enable Auto-init service which generate new token and receive in FCMService
FirebaseMessaging.getInstance().setAutoInitEnabled(true);
}
public void disableFCM(){
// Disable auto init
FirebaseMessaging.getInstance().setAutoInitEnabled(false);
new Thread(() -> {
try {
// Remove InstanceID initiate to unsubscribe all topic
// TODO: May be a better way to use FirebaseMessaging.getInstance().unsubscribeFromTopic()
FirebaseInstanceId.getInstance().deleteInstanceId();
} catch (IOException e) {
e.printStackTrace();
}
}).start();
}
}
Step 3. - FCMService implementation - token and message receiving
In the last step you need to receive the new token and send direct to your server.
Other hand you'll receive your data message and just do it what you want.
public class FCMService extends FirebaseMessagingService {
#Override
public void onNewToken(String token) {
super.onNewToken(token);
// TODO: send your new token to the server
}
#Override
public void onMessageReceived(RemoteMessage remoteMessage) {
super.onMessageReceived(remoteMessage);
String from = remoteMessage.getFrom();
Map data = remoteMessage.getData();
if (data != null) {
// TODO: handle your message and data
sendMessageNotification(message, messageId);
}
}
private void sendMessageNotification(String msg, long messageId) {
// TODO: show notification using NotificationCompat
}
}
I think this solution is clear, simple and transparent. I tested in a production environment and it's works. I hope it was helpful.
I was working on the same problem, when I had done my logout() from my application. But the problem was that after logging out, I was still getting push notifications from Firebase. I tried to delete the Firebase token. But after deleting the token in my logout() method, it is null when I query for it in my login() method. After working 2 days I finally got a solution.
In your logout() method, delete the Firebase token in the background because you can not delete Firebase token from the main thread
new AsyncTask<Void,Void,Void>() {
#Override
protected Void doInBackground(Void... params) {
try
{
FirebaseInstanceId.getInstance().deleteInstanceId();
} catch (IOException e)
{
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void result) {
// Call your Activity where you want to land after log out
}
}.execute();
In your login() method, generate the Firebase token again.
new AsyncTask<Void,Void,Void>() {
#Override
protected Void doInBackground(Void... params) {
String token = FirebaseInstanceId.getInstance().getToken();
// Used to get firebase token until its null so it will save you from null pointer exeption
while(token == null) {
token = FirebaseInstanceId.getInstance().getToken();
}
return null;
}
#Override
protected void onPostExecute(Void result) {
}
}.execute();
Developers should never unregister the client app as a mechanism for
logout or for switching between users, for the following reasons:
A registration token isn't associated with a particular logged in user. If the client app unregisters and then re-registers, the app can
receive the same registration token or a different registration token.
Unregistration and re-registration may each take up to five minutes to propagate. During this time messages may be rejected due to the
unregistered state, and messages may go to the wrong user. To make
sure that messages go to the intended user:
The app server can maintain a mapping between the current user and the registration token.
The client app can then check to ensure that messages it receives match the logged in user.
this quote is from a deprecated google documentation
But there is reasons to believe this is still true - even if the documentation above is deprecated.
You can observe this here - check out how they do it in this codelab https://github.com/firebase/functions-samples/blob/master/fcm-notifications/functions/index.js
and here
https://github.com/firebase/friendlychat-web/blob/master/cloud-functions/public/scripts/main.js
Since the getToken() is deprecated, use getInstanceId() to regenerate new token instead. It has same effect.
public static void resetInstanceId() {
new Thread(new Runnable() {
#Override
public void run() {
try {
FirebaseInstanceId.getInstance().deleteInstanceId();
FirebaseInstanceId.getInstance().getInstanceId();
Helper.log(TAG, "InstanceId removed and regenerated.");
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
Use this methods.
This is my solution, and I referred this at here
When you sign-up, use initFirebaseMessage,. and when log-out or delete
use removeFirebaseMessage().
private fun removeFirebaseMessage(){
CoroutineScope(Dispatchers.Default).launch {
FirebaseMessaging.getInstance().isAutoInitEnabled = false
FirebaseInstallations.getInstance().delete()
FirebaseMessaging.getInstance().deleteToken()
}
}
private fun initFirebaseMessage(){
val fcm = FirebaseMessaging.getInstance()
fcm.isAutoInitEnabled = true
fcm.subscribeToTopic("all")
fcm.subscribeToTopic("")
}
Another handy way to clear the firebase token and regenerated a new one using FirebaseMessaging.getInstance()
fun clearFirebaseToken() {
FirebaseMessaging.getInstance().apply {
deleteToken().addOnCompleteListener { it ->
Log.d("TAG++", "firebase token deleted ${it.result}")
token.addOnCompleteListener {
Log.d("TAG++", "firebase token generated ${it.result}")
if (it.result != null) saveTokenGenerated(it.result!!)
}
}
}
}
Just call deleteToken method on a background Thread upon Logout:
https://firebase.google.com/docs/reference/android/com/google/firebase/iid/FirebaseInstanceId.html#public-void-deletetoken-string-senderid,-string-scope
FirebaseInstanceId.getInstance().deleteToken(getString(R.string.gcm_defaultSenderId), "FCM")
The first argument takes the SenderID as it is defined in your FireBaseConsole
It takes a few seconds to update - and after that, you will no longer get FCM notifications.
I know I am late for the party. deleteInstanceId() should be called from the background thread since it's a blocking call. Just check the method deleteInstanceId() in FirebaseInstanceId() class.
#WorkerThread
public void deleteInstanceId() throws IOException {
if (Looper.getMainLooper() == Looper.myLooper()) {
throw new IOException("MAIN_THREAD");
} else {
String var1 = zzh();
this.zza(this.zzal.deleteInstanceId(var1));
this.zzl();
}
}
You can start an IntentService to delete the instance id and the data associated with it.
The firebase.iid package that contains FirebaseInstanceId is now deprecated. Auto-initialization has been migrated from Firebase Instance ID to Firebase Cloud Messaging. Also its behaviour has slighly changed. Before, a call to deleteInstanceId() would automatically generate a new token if auto-initialization was enabled. Now, the new token is only generated on the next app-start or if getToken() is called explicitly.
private suspend fun loginFCM() = withContext(Dispatchers.Default) {
val fcm = FirebaseMessaging.getInstance()
fcm.isAutoInitEnabled = true
fcm.token.await()
}
private suspend fun logoutFCM() = withContext(Dispatchers.Default) {
val fcm = FirebaseMessaging.getInstance()
fcm.isAutoInitEnabled = false // To prevent a new token to be generated automatically in the next app-start (remove if you don't care)
fcm.deleteToken().await()
}
If you want to logout completely from Firebase you can just delete the whole installation afterwards:
private suspend fun logoutFirebase() = withContext(Dispatchers.Default) {
logoutFCM()
val firebase = FirebaseInstallations.getInstance()
firebase.delete().await()
}
To wrap it all up, use background thread to delete the instanceID, the next time you login keep an eye on the Firestore/Realtime DB (if you save your tokens there), they will refresh
public void Logout() {
new Thread(){
#Override
public void run() {
super.run();
try {
FirebaseInstanceId.getInstance().deleteInstanceId();
FirebaseInstanceId.getInstance().getInstanceId();
} catch (final IOException e) {
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(Flags.this, e.getMessage(), Toast.LENGTH_SHORT).show();
}
});
}
}
}.start();
FirebaseMessaging.getInstance().setAutoInitEnabled(false);
FirebaseAuth.getInstance().signOut();
SharedPreferences sharedPreferences = getDefaultSharedPreferences(Flags.this);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.clear();
editor.apply();
startActivity(new Intent(Flags.this, MainActivity.class));
Flags.this.finish();
}
This code below I used it and it helps me, and I used Kotlin coroutine instead of Thread(Runnable{}).start() because it less cost than creating a new thread object
private fun logoutFromFCM() {
GlobalScope.launch(Dispatchers.IO) {
FirebaseInstallations.getInstance().delete()
FirebaseMessaging.getInstance().deleteToken()
FirebaseMessaging.getInstance().token.addOnCompleteListener(OnCompleteListener { task ->
if (!task.isSuccessful) {
Log.w(TAG, "Fetching FCM registration token failed", task.exception)
return#OnCompleteListener
}
// Get new FCM registration token
val token = task.result
saveFirebaseToken(token)
Log.w(TAG, "Token Updated - newToken> $token")
})
}
}
For many situations where the notifications requirements are simple, the issue of handling log out can be implemented much more easily. For example, in my case every user is subscribed to only two topics:
Global alerts topic
User specific topic defined as the users email (with replacement of # with - because # is not allowed in topic string)
For such simple scenarios simply unsubscribe from the unwanted topics on log out:
Future<void> signOut() async {
messaging.unsubscribeFromTopic(emailToTopic(_firebaseAuth.currentUser.email));
await _firebaseAuth.signOut();
}
And of course subscribe to topics only on successful log in or sign up:
Future<String> signIn({String email, String password}) async {
try {
await _firebaseAuth.signInWithEmailAndPassword(
email: email, password: password);
messaging.subscribeToTopic(emailToTopic(email));
return "Signed in";
} on FirebaseAuthException catch (e) {
return e.message;
}
}

getAuthToken y Android not calling any Callback

I've got an application in Android and I'm trying to use AccountManager to get the AuthToken and do things with Facebook or Twitter. So I've got this:
AccountManager am = AccountManager.get(this);
Account[] accounts = am.getAccountsByType("com.facebook.auth.login");
Bundle options = new Bundle();
Account myAccount=null;
for (int i=0;i<accounts.length;i++) {
if (accounts[i].type.equals("com.facebook.auth.login")) myAccount=accounts[i];
//options.putString("facebookUser", accounts[i].name);
}
am.getAuthToken(
myAccount, // Account retrieved using getAccountsByType()
"Manage your tasks", // Auth scope
options, // Authenticator-specific options
this, // Your activity
new OnTokenAcquired(), // Callback called when a token is successfully acquired
new Handler(new OnError()));
My two callbacks are onTokenAcquired:
public class OnTokenAcquired implements AccountManagerCallback<Bundle> {
#Override
public void run(AccountManagerFuture<Bundle> result) {
try {
Bundle bundle = result.getResult();
Log.e("onTokenAcquired",bundle.getString(AccountManager.KEY_AUTHTOKEN));
} catch (OperationCanceledException e) {
Log.e("onTokenAcquired","operationcanceled");
} catch (AuthenticatorException e) {
Log.e("onTokenAcquired","authenticatorexception");
} catch (IOException e) {
Log.e("onTokenAcquired","IOException");
}
}
}
and OnError:
public class OnError implements Callback {
#Override
public boolean handleMessage(Message msg) {
Log.e("onError","ERROR");
return false;
}
}
I'm following the Android Developer guide (http://developer.android.com/intl/es/training/id-auth/authenticate.html). So, I've got two options, on error or on token acquired, in each one I've got a Log.e() to read SOMETHING, but none is being writed.
Can anybody help me? If I was getting an error or the token was not being acquired at least I would have something to work on, but I just don't know what's happening.
It is not totally obvious from the documentation, but the variant of getAuthToken you are calling will never call the callback if user intervention is required. There are some workarounds here:
https://code.google.com/p/android/issues/detail?id=25473
I don't know if that is specifically the problem you're having, but it probably isn't helping.
I do not think getAuthToken is supported with the Facebook authenticator. Also the Auth scope "Manage your tasks" that you are using is the scope for "Google Tasks" and would most likely not be the correct scope to use if getAuthToken was supported.
I suggest that you use the Facebook SDK for Android instead. With this it is very easy to get the auth token. The SDK also have a fallback for users that doesn't have the official facebook installed, or a facebook account added to the phone which is very neat.
Please see also: How to retrieve an Facebook-AuthToken from the accounts saved on Android

Does SyncAdapter get notified when AccountManager removes account?

So, my question restated is when you go to Settings -> Accounts & Sync and select the an account that was created that your SyncAdapter is syncing with a cloud server, and select remove account, what happens as far as your SyncAdapter is concerned? There is a dialog that displays asking you to confirm and that the data on the phone associated with that account will be removed. I cannot easily believe that the framework can automatically remove the data my SyncAdapter has stored in the local database, but it seems to imply that removing the account will (and I would agree that is should) remove that data. Is there a addition to my SyncAdapter that will serve sort of as the callback for the account removal to handle deleting all the appropriate data from the local database? Maybe it has to be done through the AccountManager instead; my AccountManager gets notified when the account gets removed and from there I can trigger the data deletion without the SyncAdapter.
EDIT:
On a related note, is the sync manager calling my SyncAdapter for each account that it synchronizes when a new account is added? I see a onPerformSync(...) being executed for previously added accounts along with the just added account when I add an account, and would like to stop that.
I discovered the solution is to make the app's ContentProvider implement OnAccountsUpdateListener. Attach the ContentProvider as a listener in its onCreate method with account_manager.addOnAccountsUpdatedListener(this, null, false) and then implement the interface method like
#Override
public void onAccountsUpdated(final Account[] accounts) {
Ln.i("Accounts updated.");
final Iterable<String> account_list = new Iterable<String>() {
#Override
public Iterator<String> iterator() {
return new Iterator<String>() {
private final Iterator<Account> account_list = Arrays.asList(accounts).iterator();
#Override
public boolean hasNext() {
return account_list.hasNext();
}
/** Extracts the next account name and wraps it in single quotes. */
#Override
public String next() {
return "'" + account_list.next().name + "'";
}
#Override
public void remove() { throw new UnsupportedOperationException("Not implemented"); }
};
}
};
final String account_set = TextUtils.join(", ", account_list);
Ln.i("Current accounts: %s", account_set);
// Removes content that is associated with accounts that are not currently connected
final SelectionBuilder builder = new SelectionBuilder();
builder.table(Tables.CALENDARS)
.where(Calendars.CALENDAR_USER + " NOT IN (?)", account_set);
new SafeAsyncTask() {
#Override
public Void call() throws Exception {
_model.openWritableDatabase();
_model.delete(builder);
return null;
}
}.execute();
getContext().getContentResolver().notifyChange(Calendars.NO_SYNC_URI, null, false);
}
I construct a String of the currently connected accounts, then build a SQL query with that String. I perform a delete on the database in a background thread on that query to remove the data associated with accounts not currently connected. And I notify that content changed, but does not need to synchronized with the server.
No, but your Authenticator does[1]. This method is called before the account is removed:
AbstractAccountAuthenticator.getAccountRemovalAllowed(AccountAuthenticatorResponse, Account)
the Account param is the account being deleted - the default behaviour is to allow removal of the account:
return super.getAccountRemovalAllowed(response, account); // returns Bundle[{booleanResult=true}]
..but I guess it's a hook that you can use to tidy things up or block the account being removed should you wish to.
[1] - this is a dirty hack; please see Dandre's comment.
Another option is to register for the android.accounts.LOGIN_ACCOUNTS_CHANGED broadcast that the AccountManager sends out. Unfortunately, this broadcast is sent out whenever any account is changed and the broadcast does not deliver further information what has changed either.
So you'd have to query the account manager and look how many of "your" accounts it has left and delete the data of the missing ones.

Android AccountManager API

I'm struggling to understand the Android AccountManager API. As far as I got thinks working I can use the blockingGetAuthToken method and specify whether Android should provide a notification for user to allow or deny the request. Another possibility is to use getAuthToken and check if KEY_INTENT is returned. If that's the case I could start a new Activity where the user can confirm my request.
My problem is that I would like to call one of these two methods from within a Service. Is there any chance to get a callback once the user has made a decision?
Thanks for your help
If you want a callback after the user has made a decision it's probably better to use the asynchronous version:
AccountManager mgr = AccountManager.get(getApplicationContext());
Account[] accounts = mgr.getAccountsByType("com.mydomain");
// assert that accounts is not empty
You'll want to use an AccountManagerFuture<Bundle> to hold results of the authentication token. This has to be async since the Android device may ask the user to login in the meantime:
private AccountManagerFuture<Bundle> myFuture = null;
private AccountManagerCallback<Bundle> myCallback = new AccountManagerCallback<Bundle>() {
#Override public void run(final AccountManagerFuture<Bundle> arg0) {
try {
myFuture.getResult().get(AccountManager.KEY_AUTHTOKEN); // this is your auth token
} catch (Exception e) {
// handle error
}
}
}
Now you can ask for the auth token asynchronously:
myFuture = mgr.getAuthToken(accounts[0], AUTH_TOKEN_TYPE, true, myCallback, null);

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