Version 4.10.0: Improved ImageLoader and MBTiles.

MBTiles/Shared/MBTileSource.cs

@@ -0,0 +1,75 @@
+// XAML Map Control - https://github.com/ClemensFischer/XAML-Map-Control
+// © 2018 Clemens Fischer
+// Licensed under the Microsoft Public License (Ms-PL)
+
+using System;
+using System.Threading.Tasks;
+#if WINDOWS_UWP
+using Windows.UI.Xaml.Media;
+#else
+using System.Windows.Media;
+#endif
+
+namespace MapControl
+{
+    public class MBTileSource : TileSource, IDisposable
+    {
+        private readonly MBTileData tileData;
+
+        public string Name { get; private set; }
+        public string Description { get; private set; }
+        public int? MinZoom { get; private set; }
+        public int? MaxZoom { get; private set; }
+
+        public MBTileSource(string file)
+        {
+            tileData = new MBTileData(file);
+        }
+
+        public async Task Initialize()
+        {
+            await tileData.OpenAsync();
+
+            var metadata = await tileData.ReadMetadataAsync();
+
+            string name;
+            string description;
+            string minzoom;
+            string maxzoom;
+            int minZoom;
+            int maxZoom;
+
+            if (metadata.TryGetValue("name", out name))
+            {
+                Name = name;
+            }
+
+            if (metadata.TryGetValue("description", out description))
+            {
+                Description = description;
+            }
+
+            if (metadata.TryGetValue("minzoom", out minzoom) && int.TryParse(minzoom, out minZoom))
+            {
+                MinZoom = minZoom;
+            }
+
+            if (metadata.TryGetValue("maxzoom", out maxzoom) && int.TryParse(maxzoom, out maxZoom))
+            {
+                MaxZoom = maxZoom;
+            }
+        }
+
+        public void Dispose()
+        {
+            tileData.Dispose();
+        }
+
+        public override async Task<ImageSource> LoadImageAsync(int x, int y, int zoomLevel)
+        {
+            var buffer = await tileData.ReadImageBufferAsync(x, y, zoomLevel);
+
+            return buffer != null ? await ImageLoader.CreateImageSourceAsync(buffer) : null;
+        }
+    }
+}