add new media implementation for UWP which adds more functionality an…

…d fixes some problems

- fixes #308, #448, #705, #774

nuget/readme.txt

@@ -84,7 +84,14 @@ Such as:
 <string>This app needs access to the photo gallery.</string>
 
 UWP
-Set Webcam permission.
+Set Webcam, Pictures Library and Videos Library permissions.
+
+To enable the new media implementation, set the flag "UwpUseNewMediaImplementation" in the App.xaml.cs like this:
+
+```c#
+CrossMedia.SetFlags("UwpUseNewMediaImplementation");
+Xamarin.Forms.Forms.Init(e);
+```
 
 Tizen
 Please add the following Privileges in tizen-manifest.xml file:

src/Media.Plugin.Sample/Media.Plugin.Sample.UWP/App.xaml.cs

@@ -3,6 +3,7 @@
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices.WindowsRuntime;
+using Plugin.Media;
 using Windows.ApplicationModel;
 using Windows.ApplicationModel.Activation;
 using Windows.Foundation;
@@ -50,6 +51,8 @@ protected override void OnLaunched(LaunchActivatedEventArgs e)
                 // Create a Frame to act as the navigation context and navigate to the first page
                 rootFrame = new Frame();
 
+                CrossMedia.SetFlags("UwpUseNewMediaImplementation");
+
                 rootFrame.NavigationFailed += OnNavigationFailed;
                 FFImageLoading.Forms.Platform.CachedImageRenderer.Init();
                 Xamarin.Forms.Forms.Init(e);

src/Media.Plugin.Sample/Media.Plugin.Sample.UWP/Package.appxmanifest

@@ -51,5 +51,8 @@
 
   <Capabilities>
     <Capability Name="internetClient" />
+    <uap:Capability Name="picturesLibrary"/>
+    <uap:Capability Name="videosLibrary"/>
+    <DeviceCapability Name="webcam"/>
   </Capabilities>
 </Package>

src/Media.Plugin.Sample/Media.Plugin.Sample/MediaPage.xaml.cs

@@ -103,7 +103,7 @@ public MediaPage()
 				var file = await CrossMedia.Current.TakeVideoAsync(new StoreVideoOptions
 				{
 					Name = "video.mp4",
-					Directory = "DefaultVideos",
+					Directory = "DefaultVideos"
 				});
 
 				if (file == null)

src/Media.Plugin/Media.Plugin.csproj

@@ -36,6 +36,11 @@
     <DisableExtraReferences>false</DisableExtraReferences>
 
 	</PropertyGroup>
+
+	<PropertyGroup Condition=" $(TargetFramework.StartsWith('uap10.0')) ">
+		<DefineConstants>$(DefineConstants);UWP</DefineConstants>
+  </PropertyGroup>
+
 	<PropertyGroup Condition=" '$(Configuration)'=='Debug' ">
 		<DebugSymbols>true</DebugSymbols>
 		<GenerateDocumentationFile>false</GenerateDocumentationFile>

src/Media.Plugin/Shared/CrossMedia.cs

@@ -1,5 +1,7 @@
 using Plugin.Media.Abstractions;
 using System;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace Plugin.Media
 {
@@ -35,11 +37,40 @@ static IMedia CreateMedia()
         {
 #if NETSTANDARD1_0 || NETSTANDARD2_0
             return null;
+#elif UWP
+            return Flags.Contains(FeatureFlags.UwpUseNewMediaImplementation)
+                ? (IMedia)new NewMediaImplementation()
+                : new MediaImplementation();
 #else
             return new MediaImplementation();
 #endif
         }
 
+        public static bool FlagsSet;
+        static IReadOnlyList<string> flags;
+#if NETSTANDARD1_0
+        public static IReadOnlyList<string> Flags => flags ?? (flags = new List<string>());
+#else
+        public static IReadOnlyList<string> Flags => flags ?? (flags = new List<string>().AsReadOnly());
+#endif
+
+        public static void SetFlags(params string[] flags)
+		{
+			if (FlagsSet)
+			{
+				// Don't try to set the flags again if they've already been set
+				// (e.g., during a configuration change where OnCreate runs again)
+				return;
+			}
+
+#if NETSTANDARD1_0
+            CrossMedia.flags = flags.ToList();
+#else
+            CrossMedia.flags = flags.ToList().AsReadOnly();
+#endif
+			FlagsSet = true;
+		}
+
         internal static Exception NotImplementedInReferenceAssembly() =>
             new NotImplementedException("This functionality is not implemented in the portable version of this assembly.  You should reference the NuGet package from your main application project in order to reference the platform-specific implementation.");
 

src/Media.Plugin/Shared/FeatureFlags.cs

@@ -0,0 +1,9 @@
+namespace Plugin.Media
+{
+    static class FeatureFlags
+    {
+#if UWP
+        internal const string UwpUseNewMediaImplementation = "UwpUseNewMediaImplementation";
+#endif
+    }
+}