Reorganise project structure and namespaces. Remove Leaflet project and replace with Darnton.Blazor.Leaflet package.

Darnton.Blazor.DeviceInterop/Geolocation/GeolocationService.cs

@@ -0,0 +1,61 @@
+using Microsoft.JSInterop;
+using System;
+using System.Threading.Tasks;
+
+namespace Darnton.Blazor.DeviceInterop.Geolocation
+{
+    /// <summary>
+    /// An implementation of <see cref="IGeolocationService"/> that provides 
+    /// an interop layer for the device's Geolocation API.
+    /// </summary>
+    public class GeolocationService : IGeolocationService
+    {
+        private readonly IJSRuntime _jsRuntime;
+
+        /// <inheritdoc/>
+        public event EventHandler<GeolocationEventArgs> WatchPositionReceived;
+
+        /// <summary>
+        /// Constructs a <see cref="GeolocationService"/> object.
+        /// </summary>
+        /// <param name="JSRuntime"></param>
+        public GeolocationService(IJSRuntime JSRuntime)
+        {
+            _jsRuntime = JSRuntime;
+        }
+
+        /// <inheritdoc/>
+        public async Task<GeolocationResult> GetCurrentPosition(PositionOptions options = null)
+        {
+            return await _jsRuntime.InvokeAsync<GeolocationResult>("Geolocation.getCurrentPosition", options);
+        }
+
+        /// <inheritdoc/>
+        public async Task<long?> WatchPosition(PositionOptions options = null)
+        {
+            var callbackObj = DotNetObjectReference.Create(this);
+            return await _jsRuntime.InvokeAsync<int>("Geolocation.watchPosition",
+                callbackObj, nameof(SetWatchPosition), options);
+        }
+
+        /// <summary>
+        /// Invokes the <see cref="WatchPositionReceived"/> event handler.
+        /// Invoked by the success and error callbacks of the JavaScript watchPosition() function.
+        /// </summary>
+        /// <param name="watchResult">A <see cref="GeolocationResult"/> passed back from JavaScript.</param>
+        [JSInvokable]
+        public void SetWatchPosition(GeolocationResult watchResult)
+        {
+            WatchPositionReceived?.Invoke(this, new GeolocationEventArgs
+            {
+                GeolocationResult = watchResult
+            });
+        }
+
+        /// <inheritdoc/>
+        public async Task ClearWatch(long watchId)
+        {
+            await _jsRuntime.InvokeVoidAsync("Geolocation.clearWatch", watchId);
+        }
+    }
+}