example/lib/main.dart

@@ -77,9 +77,7 @@ class _MyHomePageState extends State<MyHomePage> {
         StreamManagementManager(),
         DiscoManager([]),
         RosterManager(TestingRosterStateManager("", [])),
-        PingManager(
-          const Duration(minutes: 3),
-        ),
+        PingManager(),
         MessageManager(),
         PresenceManager(),
       ])

packages/moxxmpp/lib/src/connection.dart

@@ -83,6 +83,7 @@ class XmppConnection {
     ReconnectionPolicy reconnectionPolicy,
     ConnectivityManager connectivityManager,
     this._socket, {
+    this.connectionPingDuration = const Duration(minutes: 3),
     this.connectingTimeout = const Duration(minutes: 2),
   })  : _reconnectionPolicy = reconnectionPolicy,
         _connectivityManager = connectivityManager {
@@ -142,6 +143,10 @@ class XmppConnection {
   /// UUID object to generate stanza and origin IDs
   final Uuid _uuid = const Uuid();
 
+  /// The time between sending a ping to keep the connection open
+  // TODO(Unknown): Only start the timer if we did not send a stanza after n seconds
+  final Duration connectionPingDuration;
+
   /// The time that we may spent in the "connecting" state
   final Duration connectingTimeout;
 
@@ -154,6 +159,9 @@ class XmppConnection {
   /// True if we are authenticated. False if not.
   bool _isAuthenticated = false;
 
+  /// Timer for the keep-alive ping.
+  Timer? _connectionPingTimer;
+
   /// Timer for the connecting timeout
   Timer? _connectingTimeoutTimer;
 
@@ -619,7 +627,22 @@ class XmppConnection {
     final oldState = _connectionState;
     _connectionState = state;
 
+    final sm = getNegotiatorById<StreamManagementNegotiator>(
+      streamManagementNegotiator,
+    );
+    await _sendEvent(
+      ConnectionStateChangedEvent(
+        state,
+        oldState,
+        sm?.isResumed ?? false,
+      ),
+    );
+
     if (state == XmppConnectionState.connected) {
+      _log.finest('Starting _pingConnectionTimer');
+      _connectionPingTimer =
+          Timer.periodic(connectionPingDuration, _pingConnectionOpen);
+
       // We are connected, so the timer can stop.
       _destroyConnectingTimer();
     } else if (state == XmppConnectionState.connecting) {
@@ -632,18 +655,14 @@ class XmppConnection {
     } else {
       // Just make sure the connecting timeout timer is not running
       _destroyConnectingTimer();
-    }
 
-    final sm = getNegotiatorById<StreamManagementNegotiator>(
-      streamManagementNegotiator,
-    );
-    await _sendEvent(
-      ConnectionStateChangedEvent(
-        state,
-        oldState,
-        sm?.isResumed ?? false,
-      ),
-    );
+      // The ping timer makes no sense if we are not connected
+      if (_connectionPingTimer != null) {
+        _log.finest('Destroying _pingConnectionTimer');
+        _connectionPingTimer!.cancel();
+        _connectionPingTimer = null;
+      }
+    }
   }
 
   /// Sets the routing state and logs the change
@@ -663,6 +682,22 @@ class XmppConnection {
     return _eventStreamController.stream.asBroadcastStream();
   }
 
+  /// Timer callback to prevent the connection from timing out.
+  Future<void> _pingConnectionOpen(Timer timer) async {
+    // Follow the recommendation of XEP-0198 and just request an ack. If SM is not enabled,
+    // send a whitespace ping
+    _log.finest('_pingConnectionTimer: Callback called.');
+
+    if (_connectionState == XmppConnectionState.connected) {
+      _log.finest('_pingConnectionTimer: Connected. Triggering a ping event.');
+      unawaited(_sendEvent(SendPingEvent()));
+    } else {
+      _log.finest(
+        '_pingConnectionTimer: Not connected. Not triggering an event.',
+      );
+    }
+  }
+
   /// Iterate over [handlers] and check if the handler matches [stanza]. If it does,
   /// call its callback and end the processing if the callback returned true; continue
   /// if it returned false.
@@ -1095,6 +1130,10 @@ class XmppConnection {
       _xmppManagers.containsKey(discoManager),
       'A DiscoManager is mandatory',
     );
+    assert(
+      _xmppManagers.containsKey(pingManager),
+      'A PingManager is mandatory',
+    );
   }
 
   /// The private implementation for [XmppConnection.connect]. The parameters have

packages/moxxmpp/lib/src/events.dart

@@ -26,12 +26,6 @@ class ConnectionStateChangedEvent extends XmppEvent {
   final XmppConnectionState before;
   final XmppConnectionState state;
   final bool resumed;
-
-  /// Indicates whether the connection state switched from a not connected state to a
-  /// connected state.
-  bool get connectionEstablished =>
-      before != XmppConnectionState.connected &&
-      state == XmppConnectionState.connected;
 }
 
 /// Triggered when we encounter a stream error.
@@ -49,6 +43,9 @@ class AuthenticationFailedEvent extends XmppEvent {
 /// Triggered after the SASL authentication has succeeded.
 class AuthenticationSuccessEvent extends XmppEvent {}
 
+/// Triggered when we want to ping the connection open
+class SendPingEvent extends XmppEvent {}
+
 /// Triggered when the stream resumption was successful
 class StreamResumedEvent extends XmppEvent {
   StreamResumedEvent({required this.h});

packages/moxxmpp/lib/src/ping.dart

@@ -1,23 +1,10 @@
-import 'dart:async';
-import 'package:meta/meta.dart';
 import 'package:moxxmpp/src/events.dart';
 import 'package:moxxmpp/src/managers/base.dart';
 import 'package:moxxmpp/src/managers/namespaces.dart';
 import 'package:moxxmpp/src/xeps/xep_0198/xep_0198.dart';
-import 'package:synchronized/synchronized.dart';
 
-/// This manager class is responsible to sending periodic pings, if required, using
-/// either whitespaces or Stream Management. Keep in mind, that without
-/// Stream Management, a stale connection cannot be detected.
 class PingManager extends XmppManagerBase {
-  PingManager(this._pingDuration) : super(pingManager);
-
-  /// The time between pings, when connected.
-  final Duration _pingDuration;
-
-  /// The actual timer.
-  Timer? _pingTimer;
-  final Lock _timerLock = Lock();
+  PingManager() : super(pingManager);
 
   @override
   Future<bool> isSupported() async => true;
@@ -28,73 +15,39 @@ class PingManager extends XmppManagerBase {
     );
   }
 
-  /// Cancel a potentially scheduled ping timer. Can be overriden to cancel a custom timing mechanism.
-  /// By default, cancels a [Timer.periodic] that was set up prior.
-  @visibleForOverriding
-  Future<void> cancelPing() async {
-    await _timerLock.synchronized(() {
-      logger.finest('Cancelling timer');
-      _pingTimer?.cancel();
-      _pingTimer = null;
-    });
-  }
-
-  /// Schedule a ping to be sent after a given amount of time. Can be overriden for custom timing mechanisms.
-  /// By default, uses a [Timer.periodic] timer to trigger a ping.
-  /// NOTE: This function is called whenever the connection is re-established. Custom
-  ///       implementations should thus guard against multiple timers being started.
-  @visibleForOverriding
-  Future<void> schedulePing() async {
-    await _timerLock.synchronized(() {
-      logger.finest('Scheduling new timer? ${_pingTimer != null}');
-
-      _pingTimer ??= Timer.periodic(
-        _pingDuration,
-        _sendPing,
-      );
-    });
-  }
-
-  Future<void> _sendPing(Timer _) async {
-    logger.finest('Attempting to send ping');
-    final attrs = getAttributes();
-    final socket = attrs.getSocket();
-
-    if (socket.managesKeepalives()) {
-      logger.finest('Not sending ping as the socket manages it.');
-      return;
-    }
-
-    final stream = attrs.getManagerById(smManager) as StreamManagementManager?;
-    if (stream != null) {
-      if (stream
-          .isStreamManagementEnabled() /*&& stream.getUnackedStanzaCount() > 0*/) {
-        logger.finest('Sending an ack ping as Stream Management is enabled');
-        stream.sendAckRequestPing();
-      } else if (attrs.getSocket().whitespacePingAllowed()) {
-        logger.finest(
-          'Sending a whitespace ping as Stream Management is not enabled',
-        );
-        attrs.getConnection().sendWhitespacePing();
-      } else {
-        _logWarning();
-      }
-    } else {
-      if (attrs.getSocket().whitespacePingAllowed()) {
-        attrs.getConnection().sendWhitespacePing();
-      } else {
-        _logWarning();
-      }
-    }
-  }
-
   @override
   Future<void> onXmppEvent(XmppEvent event) async {
-    if (event is ConnectionStateChangedEvent) {
-      if (event.connectionEstablished) {
-        await schedulePing();
+    if (event is SendPingEvent) {
+      logger.finest('Received ping event.');
+      final attrs = getAttributes();
+      final socket = attrs.getSocket();
+
+      if (socket.managesKeepalives()) {
+        logger.finest('Not sending ping as the socket manages it.');
+        return;
+      }
+
+      final stream =
+          attrs.getManagerById(smManager) as StreamManagementManager?;
+      if (stream != null) {
+        if (stream
+            .isStreamManagementEnabled() /*&& stream.getUnackedStanzaCount() > 0*/) {
+          logger.finest('Sending an ack ping as Stream Management is enabled');
+          stream.sendAckRequestPing();
+        } else if (attrs.getSocket().whitespacePingAllowed()) {
+          logger.finest(
+            'Sending a whitespace ping as Stream Management is not enabled',
+          );
+          attrs.getConnection().sendWhitespacePing();
+        } else {
+          _logWarning();
+        }
       } else {
-        await cancelPing();
+        if (attrs.getSocket().whitespacePingAllowed()) {
+          attrs.getConnection().sendWhitespacePing();
+        } else {
+          _logWarning();
+        }
       }
     }
   }

packages/moxxmpp/test/negotiator_test.dart

@@ -75,6 +75,7 @@ void main() {
       PresenceManager(),
       RosterManager(TestingRosterStateManager('', [])),
       DiscoManager([]),
+      PingManager(),
       EntityCapabilitiesManager('http://moxxmpp.example'),
     ])
     ..setConnectionSettings(

packages/moxxmpp/test/xeps/xep_0030_test.dart

@@ -82,6 +82,7 @@ void main() {
       PresenceManager(),
       RosterManager(TestingRosterStateManager(null, [])),
       DiscoManager([]),
+      PingManager(),
       EntityCapabilitiesManager('http://moxxmpp.example'),
     ]);
     conn.registerFeatureNegotiators([

packages/moxxmpp/test/xeps/xep_0060_test.dart

@@ -168,6 +168,7 @@ void main() {
       PresenceManager(),
       MessageManager(),
       RosterManager(TestingRosterStateManager(null, [])),
+      PingManager(),
     ]);
     connection
       ..registerFeatureNegotiators([

packages/moxxmpp/test/xeps/xep_0198_test.dart

@@ -294,6 +294,7 @@ void main() {
         PresenceManager(),
         RosterManager(TestingRosterStateManager('', [])),
         DiscoManager([]),
+        PingManager(),
         sm,
         CarbonsManager()..forceEnable(),
         EntityCapabilitiesManager('http://moxxmpp.example'),
@@ -419,6 +420,7 @@ void main() {
         PresenceManager(),
         RosterManager(TestingRosterStateManager('', [])),
         DiscoManager([]),
+        PingManager(),
         sm,
         CarbonsManager()..forceEnable(),
         //EntityCapabilitiesManager('http://moxxmpp.example'),
@@ -578,6 +580,7 @@ void main() {
         PresenceManager(),
         RosterManager(TestingRosterStateManager('', [])),
         DiscoManager([]),
+        PingManager(),
         StreamManagementManager(),
       ]);
       conn.registerFeatureNegotiators([
@@ -672,6 +675,7 @@ void main() {
         PresenceManager(),
         RosterManager(TestingRosterStateManager('', [])),
         DiscoManager([]),
+        PingManager(),
         StreamManagementManager(),
       ]);
       conn.registerFeatureNegotiators([
@@ -763,6 +767,7 @@ void main() {
         PresenceManager(),
         RosterManager(TestingRosterStateManager('', [])),
         DiscoManager([]),
+        PingManager(),
         StreamManagementManager(),
       ]);
       conn.registerFeatureNegotiators([

packages/moxxmpp/test/xmpp_test.dart

@@ -137,6 +137,7 @@ void main() {
       PresenceManager(),
       RosterManager(TestingRosterStateManager('', [])),
       DiscoManager([]),
+      PingManager(),
       StreamManagementManager(),
       EntityCapabilitiesManager('http://moxxmpp.example'),
     ]);
@@ -193,6 +194,7 @@ void main() {
       PresenceManager(),
       RosterManager(TestingRosterStateManager('', [])),
       DiscoManager([]),
+      PingManager(),
       EntityCapabilitiesManager('http://moxxmpp.example'),
     ]);
     conn.registerFeatureNegotiators([
@@ -252,6 +254,7 @@ void main() {
       PresenceManager(),
       RosterManager(TestingRosterStateManager('', [])),
       DiscoManager([]),
+      PingManager(),
       EntityCapabilitiesManager('http://moxxmpp.example'),
     ]);
     conn.registerFeatureNegotiators([SaslPlainNegotiator()]);
@@ -406,6 +409,7 @@ void main() {
       PresenceManager(),
       RosterManager(TestingRosterStateManager('', [])),
       DiscoManager([]),
+      PingManager(),
     ]);
     conn
       ..registerFeatureNegotiators([