Convert Android maps to GetMapAsync call (#824)

* [A] Move map renderer to calling GetMapAsync

* [A] Make sure Map initializes correctly with Async map fetching

diff --git a/Xamarin.Forms.Maps.Android/MapRenderer.cs b/Xamarin.Forms.Maps.Android/MapRenderer.cs
index 3316faa..2eab151 100644 (file)
--- a/Xamarin.Forms.Maps.Android/MapRenderer.cs
+++ b/Xamarin.Forms.Maps.Android/MapRenderer.cs
@@ -15,7 +15,7 @@ using Math = System.Math;
 namespace Xamarin.Forms.Maps.Android
 {
        public class MapRenderer : ViewRenderer<Map, MapView>,
-               GoogleMap.IOnCameraChangeListener
+               GoogleMap.IOnCameraChangeListener, IOnMapReadyCallback
        {
                const string MoveMessageName = "MapMoveToRegion";
 
@@ -34,9 +34,8 @@ namespace Xamarin.Forms.Maps.Android
 
                protected Map Map => Element;
 
-#pragma warning disable 618
-               protected GoogleMap NativeMap => Control.Map;
-#pragma warning restore 618
+               protected GoogleMap NativeMap;
+
                internal static Bundle Bundle
                {
                        set { s_bundle = value; }
@@ -80,7 +79,8 @@ namespace Xamarin.Forms.Maps.Android
                                        NativeMap.SetOnCameraChangeListener(null);
                                        NativeMap.InfoWindowClick -= MapOnMarkerClick;
                                        NativeMap.Dispose();
-                               }                                               
+                                       NativeMap = null;
+                                }
 
                                Control?.OnDestroy();
                        }
@@ -106,32 +106,17 @@ namespace Xamarin.Forms.Maps.Android
 
                                MessagingCenter.Unsubscribe<Map, MapSpan>(this, MoveMessageName);
 
-#pragma warning disable 618
-                               if (oldMapView.Map != null)
+                               if (NativeMap != null)
                                {
-#pragma warning restore 618
-
-#pragma warning disable 618
-                                       oldMapView.Map.SetOnCameraChangeListener(null);
-#pragma warning restore 618
+                                       NativeMap.SetOnCameraChangeListener(null);
                                        NativeMap.InfoWindowClick -= MapOnMarkerClick;
+                                       NativeMap = null;
                                }
 
                                oldMapView.Dispose();
                        }
 
-                       GoogleMap map = NativeMap;
-                       if (map != null)
-                       {
-                               map.SetOnCameraChangeListener(this);
-                               NativeMap.InfoWindowClick += MapOnMarkerClick;
-
-                               map.UiSettings.ZoomControlsEnabled = Map.HasZoomEnabled;
-                               map.UiSettings.ZoomGesturesEnabled = Map.HasZoomEnabled;
-                               map.UiSettings.ScrollGesturesEnabled = Map.HasScrollEnabled;
-                               map.MyLocationEnabled = map.UiSettings.MyLocationButtonEnabled = Map.IsShowingUser;
-                               SetMapType();
-                       }
+                       Control.GetMapAsync(this);
 
                        MessagingCenter.Subscribe<Map, MapSpan>(this, MoveMessageName, OnMoveToRegionMessage, Map);
 
@@ -179,13 +164,19 @@ namespace Xamarin.Forms.Maps.Android
 
                        if (_init)
                        {
-                               MoveToRegion(Element.LastMoveToRegion, false);
-                               OnCollectionChanged(Element.Pins, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
-                               _init = false;
+                               if (NativeMap != null)
+                               {
+                                       MoveToRegion(Element.LastMoveToRegion, false);
+                                       OnCollectionChanged(Element.Pins, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+                                       _init = false;
+                               }
                        }
                        else if (changed)
                        {
-                               UpdateVisibleRegion(NativeMap.CameraPosition.Target);
+                               if (NativeMap != null)
+                               {
+                                       UpdateVisibleRegion(NativeMap.CameraPosition.Target);
+                               }
                                MoveToRegion(Element.LastMoveToRegion, false);
                        }
                }
@@ -371,5 +362,23 @@ namespace Xamarin.Forms.Maps.Android
                        double dlong = Math.Max(Math.Abs(ul.Longitude - lr.Longitude), Math.Abs(ur.Longitude - ll.Longitude));
                        Element.VisibleRegion = new MapSpan(new Position(pos.Latitude, pos.Longitude), dlat, dlong);
                }
+
+               void IOnMapReadyCallback.OnMapReady(GoogleMap map)
+               {
+                       NativeMap = map;
+                       if (map == null)
+                       {
+                               return;
+                       }
+
+                       map.SetOnCameraChangeListener(this);
+                       map.InfoWindowClick += MapOnMarkerClick;
+
+                       map.UiSettings.ZoomControlsEnabled = Map.HasZoomEnabled;
+                       map.UiSettings.ZoomGesturesEnabled = Map.HasZoomEnabled;
+                       map.UiSettings.ScrollGesturesEnabled = Map.HasScrollEnabled;
+                       map.MyLocationEnabled = map.UiSettings.MyLocationButtonEnabled = Map.IsShowingUser;
+                       SetMapType();
+               }
        }
 }
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