IEmulatorServiceProvider and BasicServiceProvider - restrict to IEmulatorServices

BizHawk.Emulation.Common/Base Implementations/BasicServiceProvider.cs

@@ -21,7 +21,11 @@ namespace BizHawk.Emulation.Common
 
 			Type coreType = core.GetType();
 
-			foreach (Type service in coreType.GetInterfaces().Where(t => t != typeof(IEmulatorService)))
+			var services = coreType.GetInterfaces()
+				.Where(t => typeof(IEmulatorService).IsAssignableFrom(t))
+				.Where(t => t != typeof(IEmulatorService));
+
+			foreach (Type service in services)
 			{
 				Services.Add(service, core);
 			}
@@ -40,7 +44,8 @@ namespace BizHawk.Emulation.Common
 		/// </summary>
 		/// <typeparam name="T"></typeparam>
 		/// <param name="provider"></param>
-		public void Register<T>(T provider)
+		public void Register<T>(T provider) 
+			where T : IEmulatorService
 		{
 			if (provider == null)
 				throw new ArgumentNullException("provider");
@@ -48,6 +53,7 @@ namespace BizHawk.Emulation.Common
 		}
 
 		public T GetService<T>()
+			where T : IEmulatorService
 		{
 			return (T)GetService(typeof(T));
 		}
@@ -62,6 +68,7 @@ namespace BizHawk.Emulation.Common
 		}
 
 		public bool HasService<T>()
+			where T : IEmulatorService
 		{
 			return HasService(typeof(T));
 		}

BizHawk.Emulation.Common/Interfaces/IEmulatorServiceProvider.cs

@@ -8,7 +8,7 @@ namespace BizHawk.Emulation.Common
 		/// <summary>
 		/// Returns whether or not T is available
 		/// </summary>
-		bool HasService<T>();
+		bool HasService<T>() where T : IEmulatorService;
 		
 		/// <summary>
 		/// Returns whether or not t is available
@@ -19,7 +19,7 @@ namespace BizHawk.Emulation.Common
 		/// Returns an instance of T if T is available
 		/// Else returns null
 		/// </summary>
-		T GetService<T>();
+		T GetService<T>() where T : IEmulatorService;
 
 		/// <summary>
 		/// Returns an instance of t if t is available