foreground_check library

Classes

LifecycleQueryResult: Outcome of queryLifecycleState.
LifecycleReported: fdb_helper reported an AppLifecycleState.name (null if the engine has not reported one yet).
LifecycleUnavailable: The lifecycle could not be determined for a benign reason: no session, no fdb_helper, an older fdb_helper without ext.fdb.lifecycle, app died, or any other non-timeout failure. Callers stay silent.
LifecycleVmNotResponding: The query timed out while the app PID is alive: the VM is unresponsive.

lifecycleQueryTimeout → const Duration: Upper bound for queryLifecycleState so a hung VM never stalls a command.
vmNotRespondingWarning → const String: Warning emitted when the lifecycle query times out while the app PID is alive — the VM is unresponsive, most likely because the OS suspended the backgrounded app.

classifyLifecycleQueryError(Object error, {required bool appAlive}) → LifecycleQueryResult: Classifies a failure of the lifecycle query. Only a timeout (or an explicit VmNotRespondingException) with the app still alive counts as "not responding"; everything else is LifecycleUnavailable.
foregroundWarning(String? lifecycleState) → String?: Returns a WARNING: ... line when lifecycleState (an AppLifecycleState.name reported by fdb_helper) means the app is not the visible foreground app, or null when it is (resumed) or unknown (null, e.g. an older fdb_helper that does not report lifecycle).
lifecycleQueryWarning(LifecycleQueryResult result) → String?: Maps a LifecycleQueryResult to the warning line to emit, or null.
queryLifecycleState({Duration timeout = lifecycleQueryTimeout}) → Future<LifecycleQueryResult>: Best-effort query of the app's lifecycle state via ext.fdb.lifecycle.