Improvements in application initialization

When initializing XWT, the backend can now be
specified using an enumeration. 

XWT now loads backends which match the version
number of Xwt.dll.

GtkTest/Main.cs

@@ -25,6 +25,7 @@
 // THE SOFTWARE.
 using System;
 using Samples;
+using Xwt;
 
 namespace GtkTest
 {
@@ -32,7 +33,7 @@ namespace GtkTest
 	{
 		public static void Main (string[] args)
 		{
-			App.Run ("Xwt.GtkBackend.GtkEngine, Xwt.Gtk, Version=1.0.0.0");
+			App.Run (ToolkitType.Gtk);
 		}
 	}
 }

MacTest/MacTest.csproj

@@ -10,6 +10,7 @@
     <OutputType>Exe</OutputType>
     <RootNamespace>MacTest</RootNamespace>
     <AssemblyName>MacTest</AssemblyName>
+    <SuppressXamMacMigration>True</SuppressXamMacMigration>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>True</DebugSymbols>

MacTest/Main.cs

@@ -10,7 +10,7 @@ namespace MacTest
 	{
 		static void Main (string [] args)
 		{
-			App.Run ("Xwt.Mac.MacEngine, Xwt.Mac, Version=1.0.0.0");
+			App.Run (ToolkitType.Cocoa);
 		}
 	}
 }	

Samples/App.cs

@@ -7,9 +7,9 @@ namespace Samples
 {
 	public class App
 	{
-		public static void Run (string engineType)
+		public static void Run (ToolkitType type)
 		{
-			Application.Initialize (engineType);
+			Application.Initialize (type);
 			
 			MainWindow w = new MainWindow ();
 			w.Title = "Xwt Demo Application";

WpfTest/Main.cs

@@ -25,6 +25,7 @@
 
 using System;
 using Samples;
+using Xwt;
 
 namespace WpfTest
 {
@@ -33,7 +34,7 @@ namespace WpfTest
 		[STAThread]
 		public static void Main(string[] args)
 		{
-			App.Run ("Xwt.WPFBackend.WPFEngine, Xwt.WPF, Version=1.0.0.0");
+			App.Run (ToolkitType.Wpf);
 		}
 	}
 }

Xwt.Mac/Xwt.Mac.csproj

@@ -10,6 +10,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>Xwt.Mac</RootNamespace>
     <AssemblyName>Xwt.Mac</AssemblyName>
+    <SuppressXamMacMigration>True</SuppressXamMacMigration>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>True</DebugSymbols>

Xwt/Xwt/Application.cs

@@ -58,6 +58,11 @@ namespace Xwt
 			Initialize (null);
 		}
 		
+		public static void Initialize (ToolkitType type)
+		{
+			Initialize (GetBackendType (type));
+		}
+
 		public static void Initialize (string backendType)
 		{
 			InitBackend (backendType);
@@ -202,18 +207,25 @@ namespace Xwt
 			if (type != null && LoadBackend (type))
 				return;
 			
-			if (LoadBackend ("Xwt.GtkBackend.GtkEngine, Xwt.Gtk, Version=1.0.0.0"))
-				return;
-			
-			if (LoadBackend ("Xwt.Mac.MacEngine, Xwt.Mac, Version=1.0.0.0"))
-				return;
-			
-			if (LoadBackend ("Xwt.WPFBackend.WPFEngine, Xwt.WPF, Version=1.0.0.0"))
-				return;
-			
 			throw new InvalidOperationException ("Xwt engine not found");
 		}
-		
+
+		internal static string GetBackendType (ToolkitType type)
+		{
+			string version = typeof(Application).Assembly.GetName ().Version.ToString ();
+			
+			switch (type) {
+			case ToolkitType.Gtk:
+				return "Xwt.GtkBackend.GtkEngine, Xwt.Gtk, Version=" + version;
+			case ToolkitType.Cocoa:
+				return "Xwt.Mac.MacEngine, Xwt.Mac, Version=" + version;
+			case ToolkitType.Wpf:
+				return "Xwt.WPFBackend.WPFEngine, Xwt.WPF, Version=" + version;
+			default:
+				throw new ArgumentException ("Invalid toolkit type");
+			}
+		}
+
 		internal static void NotifyException (Exception ex)
 		{
 			var unhandledException = UnhandledException;
@@ -227,5 +239,12 @@ namespace Xwt
 			}
 		}
 	}
+
+	public enum ToolkitType
+	{
+		Gtk,
+		Cocoa,
+		Wpf
+	}
 }