didChangeAppLifecycleState method

@override void didChangeAppLifecycleState(AppLifecycleState state)

Called when the system puts the app in the background or returns the app to the foreground.

An example of implementing this method is provided in the class-level documentation for the WidgetsBindingObserver class.

This method exposes notifications from SystemChannels.lifecycle.

See also:

• AppLifecycleListener, an alternative API for responding to application lifecycle changes.

Implementation

@override
void didChangeAppLifecycleState(AppLifecycleState state) {
  final timestamp = DateTime.now().toIso8601String();
  String currentScreen = 'Unknown';

  if (_activeScreens.isNotEmpty) {
    _currentTracker = _activeScreens.values.last;
    currentScreen = _currentTracker?.screenName ?? 'Unknown';
  }

  switch (state) {
    case AppLifecycleState.resumed:
      developer.log('App moved to foreground at $timestamp on $currentScreen');

      if (_currentTracker != null && _currentTracker!.endTime != null) {
        final newTracker = ScreenTimeTracker(
          screenName: _currentTracker!.screenName,
          startTime: DateTime.now(),
          deviceInfo: _currentTracker!.deviceInfo,
          sessionId: sessionId,
        );
        _activeScreens[_activeScreens.keys.last] = newTracker;

        WidgetsBinding.instance.addPostFrameCallback((_) {
          final renderDuration = DateTime.now().difference(newTracker.startTime);
          newTracker.setRenderTime(renderDuration);
          developer.log('Tracking:::: ${newTracker.toString()}');
        });
      }
      break;

    case AppLifecycleState.paused:
      developer.log('App moved to background at $timestamp on $currentScreen');

      if (_currentTracker != null && _currentTracker!.endTime == null) {
        _currentTracker?.setEndTime(DateTime.now());
        developer.log('Tracking:::: ${_currentTracker.toString()}');
        _sendTracker(_currentTracker!);
      }
      break;

    case AppLifecycleState.inactive:
    case AppLifecycleState.detached:
      break;

    case AppLifecycleState.hidden:
      break;
  }
}