Fix #42 implement Geocoder in iOS

Xamarin.Forms.GoogleMaps/Xamarin.Forms.GoogleMaps.iOS/FormsGoogleMaps.cs

@@ -1,12 +1,15 @@
 using System;
 using Google.Maps;
+using Xamarin.Forms.GoogleMaps.iOS;
+
 namespace Xamarin
 {
     public static class FormsGoogleMaps
     {
         public static void Init(string apiKey)
         {
             MapServices.ProvideAPIKey(apiKey);
+            GeocoderBackend.Register();
         }
     }
 }

Xamarin.Forms.GoogleMaps/Xamarin.Forms.GoogleMaps.iOS/GeocoderBackend.cs

@@ -0,0 +1,61 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+#if __UNIFIED__
+using CoreLocation;
+using AddressBookUI;
+#else
+using MonoTouch.AddressBookUI;
+using MonoTouch.CoreLocation;
+#endif
+#if __UNIFIED__
+using RectangleF = CoreGraphics.CGRect;
+using SizeF = CoreGraphics.CGSize;
+using PointF = CoreGraphics.CGPoint;
+
+#else
+using nfloat=global::System.Single;
+using nint=global::System.Int32;
+using nuint=global::System.UInt32;
+#endif
+
+namespace Xamarin.Forms.GoogleMaps.iOS
+{
+    internal class GeocoderBackend
+    {
+        public static void Register()
+        {
+            Geocoder.GetPositionsForAddressAsyncFunc = GetPositionsForAddressAsync;
+            Geocoder.GetAddressesForPositionFuncAsync = GetAddressesForPositionAsync;
+        }
+
+        static Task<IEnumerable<string>> GetAddressesForPositionAsync(Position position)
+        {
+            var location = new CLLocation(position.Latitude, position.Longitude);
+            var geocoder = new CLGeocoder();
+            var source = new TaskCompletionSource<IEnumerable<string>>();
+            geocoder.ReverseGeocodeLocation(location, (placemarks, error) =>
+            {
+                if (placemarks == null)
+                    placemarks = new CLPlacemark[0];
+                IEnumerable<string> addresses = placemarks.Select(p => ABAddressFormatting.ToString(p.AddressDictionary, false));
+                source.SetResult(addresses);
+            });
+            return source.Task;
+        }
+
+        static Task<IEnumerable<Position>> GetPositionsForAddressAsync(string address)
+        {
+            var geocoder = new CLGeocoder();
+            var source = new TaskCompletionSource<IEnumerable<Position>>();
+            geocoder.GeocodeAddress(address, (placemarks, error) =>
+            {
+                if (placemarks == null)
+                    placemarks = new CLPlacemark[0];
+                IEnumerable<Position> positions = placemarks.Select(p => new Position(p.Location.Coordinate.Latitude, p.Location.Coordinate.Longitude));
+                source.SetResult(positions);
+            });
+            return source.Task;
+        }
+    }
+}

Xamarin.Forms.GoogleMaps/Xamarin.Forms.GoogleMaps.iOS/Xamarin.Forms.GoogleMaps.iOS.csproj

@@ -74,6 +74,7 @@
     <Compile Include="TouchAsyncTileLayer.cs" />
     <Compile Include="TouchSyncTileLayer.cs" />
     <Compile Include="Extensions\BitmapDescriptorExtensions.cs" />
+    <Compile Include="GeocoderBackend.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />