Develop Reference

Listen to notifications using Flutter

I'm a beginner to android app development. I waned to access incoming notifications from my flutter app. I tried https://pub.dev/packages/notifications package. But I can't find how it works.
I also tried to use the NotificationListener but can't figure it out.
Please help if you can.

The notifications package listens to notifications/push messages received by the device. The messages received should be handled inside onData.
Notifications _notifications;
StreamSubscription<NotificationEvent> _subscription;
...
void onData(NotificationEvent event) {
debugPrint('Event received: $event');
}
void startListening() {
_notifications = new Notifications();
try {
_subscription = _notifications!.notificationStream!.listen(onData);
} on NotificationException catch (exception) {
debugPrint(exception);
}
}

Can't able to receive group chat messages using smack-android:4.1.4

I am developing chat app using smack library. I have an issue in group chat. In my app, i am creating a group and in that members are auto-joined.i want to notify all user when I send a message in the group even if they had not initiated a chat.My code is as follow in that I have place listener in init method but unable to receive a message.
multiUserChatManager = MultiUserChatManager.getInstanceFor(mConnection);
mMultiUserChat = multiUserChatManager.getMultiUserChat(to);
mConnection.addAsyncStanzaListener(this, null);
DiscussionHistory history = new DiscussionHistory();
history.setMaxStanzas(0);
mMultiUserChat.addMessageListener(this);
mConnection.addSyncStanzaListener(this, null);
try {
mMultiUserChat.join(from, "", history, SmackConfiguration.getDefaultPacketReplyTimeout());
} catch (SmackException.NoResponseException e) {
e.printStackTrace();
} catch (XMPPException.XMPPErrorException e) {
e.printStackTrace();
} catch (SmackException.NotConnectedException e) {
e.printStackTrace();
}
Here is message listener of group
#Override
public void processMessage(Message message) {
Logg.e(TAG,"Message received group..");
}
I don't know why this method does not call when someone send message in group, even I joined group, If I create 1 group and joined 2 users, when 1 user sends message in group then user2 can't able to receive message, but when user 2 send message inside this group then they both are able to receive messages.
Please help me, I can't able to find the solution. Please don't give suggestion which is already deprecated.
Thanks in Advance.!!

I'm full editing answer after full code review. -again-
I suggest to refactor your code to keep separation of roles in more than 1 huge class.
Basically you are especting messages in wrong listener due to many "addasync - addsync" in your code and you are able to receive messages just as side effect of your monster-class-all-in!
I see many optimization you need to apply to your code.
It's too long to explain and out of the question, however, just as example:
1. sendGroupMessage You can check by MultiUserChatManager if you
already joined the chat and then send the message. You must fire a
"join" just once, not everytime you want to send a message.
2. mMultiUserChat.addMessageListener(this);
A listener must be added ONCE or you'll create tons of threads. Probably it works because you have a singleton. While you have a listener, you don't need to add it anymore to that chat if you don't remove it.
mConnection.addSyncStanzaListener(this, null);
Be carefull: you are adding your listener (wich one? You implements tons of listeners with same class) to your connection. Before or later your code will eat an important stanza (prolly a custom IQ) and you'll have an hard to discovery side effects.
mConnection.addAsyncStanzaListener(this, null); same of 3
Check for ProviderManager.addExtensionProvider(), before or later
you'll need some.
Hope that helps.

Try This
step1 : 1 remove this
mConnection.addAsyncStanzaListener(this, null);
mConnection.addSyncStanzaListener(this, null);
Step 2 : add this
private StanzaTypeFilter serverFilter;
private StanzaListener stanzaListener = null;
private XMPPTCPConnection mConnection;
registerStanzaListener(); // where you init connection
public void registerStanzaListener() {
serverFilter = new StanzaTypeFilter(Message.class);
if (stanzaListener != null) {
mConnection.removeAsyncStanzaListener(stanzaListener);
}
stanzaListener = new StanzaListener() {
#Override
public void processPacket(Stanza packet) throws SmackException.NotConnectedException {
processMessage((Message) packet);
}
};
mConnection.addAsyncStanzaListener(stanzaListener, serverFilter);
}
}

Can I scan for iBeacons with Play Services 9.2?

In the 9.2 Release Notes of Google Play services I found the following:
Nearby
This release removes the requirement that clients use the Proximity Beacon API to manage their beacons. Nearby will now return parsed BLE advertisements directly, allowing clients to use their own solution to interpret those advertisements.
That sounds to me, as if I should be able to subscribe to Nearby Messages with Strategy.BLE_ONLY and get information about BLE beacons (which includes iBeacons) in the vicinity without "owning"/registering the beacons vie Proximity Beacon API.
Do I understand that correctly? Does anyone have a helpful link to a sample or other resources that might help implementing this feature?

Subscribe with a MessageFilter that uses includeIBeaconIds.
The code would look something like:
MessageFilter filter = new MessageFilter.Builder()
.includeIBeaconIds(MY_IBEACON_PROXIMITY_UUID, null, null)
.build();
SubscribeOptions options = new SubscribeOptions.Builder()
.setFilter(filter)
.setStrategy(Strategy.BLE_ONLY)
.build();
MessageListener listener = new MessageListener() {
#Override
public void onFound(Message message) {
IBeaconId beaconId = IBeaconId.from(message);
Log.i("Test", "Saw iBeacon " + beaconId);
}
};
Nearby.Messages.subscribe(apiClient, messageListener, options);

Does anyone have a helpful link to a sample or other resources that might help implementing this feature?
Listening to iBeacon from an Android device is possible as confirmed in this SO thread and this too.
You can make use of the AltBeacon/android-beacon-library.
It allows Android devices to use beacons much like iOS devices do. An
app can request to get notifications when one or more beacons appear
or disappear. An app can also request to get a ranging update from one
or more beacons at a frequency of approximately 1Hz.
Don't forget to read about Getting Beacon Messages from the Google Docs too.
Here's a snippet when subscribing in the foreground:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
mMessageListener = new MessageListener() {
#Override
public void onFound(Message message) {
String messageAsString = new String(message.getContent());
Log.d(TAG, "Found message: " + messageAsString);
}
#Override
public void onLost(Message message) {
String messageAsString = new String(message.getContent());
Log.d(TAG, "Lost sight of message: " + messageAsString);
}
}
}

TweetViewFetchAdapter.setTweetIds does not work in android

I want to display some tweets with the twitter API in my app. To do so I have fetched some tweet ids (which is working without any hassle) and use the TweetViewFetchAdapter adapter provided by the Twitter API to display my tweets.
The weird thing is: this has worked at some point! But then suddenly it stopped working (company app, multiple people working on the code but I haven't seen any changes to the twitter stuff in the time between working and not working)
The code is super straight forward taken from the official twitter site:
// fill the tweet adapter with the loaded tweet ids
#Override
protected void onPostExecute(List<Long> params){
if (params != null && params.size() > 0) {
adapter.setTweetIds(params,
new LoadCallback<List<Tweet>>() {
#Override
public void success(List<Tweet> tweets) {
Log.i("twitter", "Success!");
}
#Override
public void failure(TwitterException exception) {
Log.e("twitter", "Exception: " + exception.getMessage());
}
});
}
Log.i("twitter", "params.size = " + params.size() + "adapter.tweetCount = " + adapter.getCount());
}
(inside an AsyncTask). The adapter seems to fail to set the tweet ids as the debug output is I/twitter﹕ params.size = 10 adapter.tweet Count = 0
I tried to debug/have a log output in the success/failure callbacks, but I never got anything as if the methods would never be called (quite weird actually..)
Regarding log cat output I haven't seen any, but I'm afraid there is a little chance I might have messed it up as we just recently moved to Android Studio and I just can't get my head around some stuff there yet.

Issue was caused by an wrong version of okhttp / okhttp-urlconnection.
The weird part is that no debug messages was shown. This code resolved the debug message issue and helped resolve the issue overall:
final Fabric fabric = new Fabric.Builder(this)
.kits(new Twitter(authConfig))
.logger(new DefaultLogger(Log.DEBUG))
.debuggable(true)
.build();
Fabric.with(fabric);
Overall fix: change build.gradle:
dependencies {
// ...
compile 'com.squareup.okhttp:okhttp:2.3.0'
compile 'com.squareup.okhttp:okhttp-urlconnection:2.3.0'
}
Original conversation: https://twittercommunity.com/t/adapter-settweetid-seems-to-be-unable-to-load-the-tweets-but-doesnt-fire-a-success-failure-callback/36506/13

Pebble Communication Issues [AppSync/AppMessage]

I'm currently attempting to use AppSync to sync a piece of data between an android app and a pebble app. However, I seem to not be able to get the pebble to realize that any data is being transferred - that is, no logs are being produced where they should be. What is really bothering me is that this is essentially the code found in the pebble weather example. I've pasted the relevant bits of code below - could someone possibly look it over and suggest where any issues may be? I've made sure that the UUIDs in both programs (pebble app and android app) are the same, and that they are on the same network, and that the pebble is actually connected to the phone, and that the android function is actually being called and all.
Snippet of pebble app code:
static void sync_error_callback(DictionaryResult dict_error, AppMessageResult app_message_error, void *context) {
APP_LOG(APP_LOG_LEVEL_DEBUG, "App Message Sync Error: %d", app_message_error);
}
static void sync_tuple_changed_callback(const uint32_t key, const Tuple* new_tuple, const Tuple* old_tuple, void* context) {
APP_LOG(APP_LOG_LEVEL_DEBUG, new_tuple->value->cstring);
}
void home_screen_load() {
// set up each one of the SimpleMenuItems
Tuplet initial_values[] = {
TupletCString(0x0, "Initial 1")
};
app_sync_init(&sync, sync_buffer, sizeof(sync_buffer), initial_values, ARRAY_LENGTH(initial_values), sync_tuple_changed_callback, sync_error_callback, NULL);
}
Snippet of android app:
final UUID PEBBLE_APP_UUID = UUID.fromString("10549fd4-1fe4-4d30-8a18-6f2f8149f8fd");
public void sendDataToWatch(String toSend) {
// Build up a Pebble dictionary containing the weather icon and the current temperature in degrees celsius
PebbleDictionary data = new PebbleDictionary();
data.addString(0x0, toSend);
PebbleKit.sendDataToPebble(getApplicationContext(), PEBBLE_APP_UUID, data);
}

To debug this type of problem, you should set a inbox_dropped handler and see if you get anything there.
After initializing AppMessage and AppSync, call:
app_message_register_inbox_dropped(appmsg_in_dropped);
And add this function:
static void appmsg_in_dropped(AppMessageResult reason, void *context) {
APP_LOG(APP_LOG_LEVEL_DEBUG, "In dropped: %s", translate_error(reason));
}
Take a look at this question for the source of the translate_error function.