Geolocation - Location Updates xamarin#290 - added ContinuousLocation…

…Listener ported from Geolocator.Plugin.GeolocationContinuousListener
alexreich · Dec 27, 2019 · 7c043df · 7c043df
1 parent a719d90
commit 7c043df
Showing 1 changed file with 87 additions and 0 deletions.
diff --git a/Xamarin.Essentials/Geolocation/Geolocation.android.cs b/Xamarin.Essentials/Geolocation/Geolocation.android.cs
@@ -271,4 +271,91 @@ void ILocationListener.OnStatusChanged(string provider, [GeneratedEnum] Availabi
             }
         }
     }
+
+    class ContinuousLocationListener : Java.Lang.Object, ILocationListener
+    {
+        readonly HashSet<string> activeProviders = new HashSet<string>();
+        readonly LocationManager manager;
+        IList<string> providers;
+
+        string activeProvider;
+        AndroidLocation lastLocation;
+        TimeSpan timePeriod;
+
+        public ContinuousLocationListener(LocationManager manager, TimeSpan timePeriod, IList<string> providers)
+        {
+            this.manager = manager;
+            this.timePeriod = timePeriod;
+            this.providers = providers;
+
+            foreach (var p in providers)
+            {
+                if (manager.IsProviderEnabled(p))
+                    activeProviders.Add(p);
+            }
+        }
+
+        internal Action<AndroidLocation> LocationHandler { get; set; }
+
+        void ILocationListener.OnLocationChanged(AndroidLocation location)
+        {
+            if (location.Provider != activeProvider)
+            {
+                if (activeProvider != null && manager.IsProviderEnabled(activeProvider))
+                {
+                    var pr = manager.GetProvider(location.Provider);
+                    var lapsed = GetTimeSpan(location.Time) - GetTimeSpan(lastLocation.Time);
+
+                    if (pr.Accuracy > manager.GetProvider(activeProvider).Accuracy
+                      && lapsed < timePeriod.Add(timePeriod))
+                    {
+                        location.Dispose();
+                        return;
+                    }
+                }
+
+                activeProvider = location.Provider;
+            }
+
+            var previous = Interlocked.Exchange(ref lastLocation, location);
+            if (previous != null)
+                previous.Dispose();
+
+            LocationHandler?.Invoke(location);
+        }
+
+        public void OnProviderDisabled(string provider)
+        {
+            lock (activeProviders)
+                activeProviders.Remove(provider);
+        }
+
+        public void OnProviderEnabled(string provider)
+        {
+            if (provider == LocationManager.PassiveProvider)
+                return;
+
+            lock (activeProviders)
+                activeProviders.Add(provider);
+        }
+
+        public void OnStatusChanged(string provider, Availability status, Bundle extras)
+        {
+            switch (status)
+            {
+                case Availability.Available:
+                    OnProviderEnabled(provider);
+                    break;
+
+                case Availability.OutOfService:
+                    OnProviderDisabled(provider);
+                    break;
+            }
+        }
+
+        TimeSpan GetTimeSpan(long time)
+        {
+            return new TimeSpan(TimeSpan.TicksPerMillisecond * time);
+        }
+    }
 }