background timer for locking

src/App/Abstractions/Services/ILockService.cs

@@ -6,9 +6,11 @@ namespace Bit.App.Abstractions
 {
     public interface ILockService
     {
+        bool CheckForLockInBackground { get; set; }
         void UpdateLastActivity(DateTime? activityDate = null);
         Task<LockType> GetLockTypeAsync(bool forceLock);
         Task CheckLockAsync(bool forceLock);
         bool TopPageIsLock();
+        void StartLockTimer();
     }
 }

src/App/App.cs

@@ -86,11 +86,15 @@ namespace Bit.App
                     await Task.Run(() => FullSyncAsync()).ConfigureAwait(false);
                 });
             }
+
+            // TODO: Still testing.
+            //_lockService.StartLockTimer();
         }
 
         protected async override void OnStart()
         {
             // Handle when your app starts
+            _lockService.CheckForLockInBackground = false;
             await _lockService.CheckLockAsync(false);
 
             if(string.IsNullOrWhiteSpace(_options.Uri))
@@ -113,6 +117,7 @@ namespace Bit.App
         protected override void OnSleep()
         {
             // Handle when your app sleeps
+            _lockService.CheckForLockInBackground = true;
             Debug.WriteLine("OnSleep");
 
             SetMainPageFromAutofill();
@@ -126,6 +131,7 @@ namespace Bit.App
         protected async override void OnResume()
         {
             base.OnResume();
+            _lockService.CheckForLockInBackground = false;
 
             // workaround for app compat bug
             // ref https://forums.xamarin.com/discussion/62414/app-resuming-results-in-crash-with-formsappcompatactivity

src/App/Services/LockService.cs

@@ -17,6 +17,7 @@ namespace Bit.App.Services
         private readonly IAppSettingsService _appSettings;
         private readonly IAuthService _authService;
         private readonly IFingerprint _fingerprint;
+        private bool _timerCreated = false;
 
         public LockService(
             ISettings settings,
@@ -30,6 +31,8 @@ namespace Bit.App.Services
             _fingerprint = fingerprint;
         }
 
+        public bool CheckForLockInBackground { get; set; } = true;
+
         public void UpdateLastActivity(DateTime? activityDate = null)
         {
             if(_appSettings.Locked)
@@ -136,5 +139,30 @@ namespace Bit.App.Services
 
             return false;
         }
+
+        public void StartLockTimer()
+        {
+            if(_timerCreated)
+            {
+                return;
+            }
+
+            _timerCreated = true;
+            Device.StartTimer(TimeSpan.FromMinutes(1), () =>
+            {
+                if(CheckForLockInBackground && !_appSettings.Locked)
+                {
+                    System.Diagnostics.Debug.WriteLine("Check lock from timer at " + DateTime.Now);
+                    var lockType = GetLockTypeAsync(false).GetAwaiter().GetResult();
+                    if(lockType != LockType.None)
+                    {
+                        System.Diagnostics.Debug.WriteLine("Locked from timer at " + DateTime.Now);
+                        _appSettings.Locked = true;
+                    }
+                }
+
+                return true;
+            });
+        }
     }
 }