[Mac] Avoid class conflicts for multiple windows

When creating multiple windows, their classes must have different class
names or they will fail to construct.

This commit ensures their names are unique. It also fixes a potential
memory leak in the Icon setter.

diff --git a/Source/OpenTK/Platform/MacOS/CocoaNativeWindow.cs b/Source/OpenTK/Platform/MacOS/CocoaNativeWindow.cs
index 0075825..cd6876e 100644 (file)
--- a/Source/OpenTK/Platform/MacOS/CocoaNativeWindow.cs
+++ b/Source/OpenTK/Platform/MacOS/CocoaNativeWindow.cs
@@ -1,14 +1,17 @@
 using System;
-using OpenTK.Graphics;
-using System.Drawing;
 using System.ComponentModel;
-using OpenTK.Input;
 using System.Diagnostics;
+using System.Drawing;
+using System.Threading;
+using OpenTK.Graphics;
+using OpenTK.Input;
 
 namespace OpenTK.Platform.MacOS
 {
     class CocoaNativeWindow : INativeWindow
     {
+        static volatile int UniqueId;
+
         public event EventHandler<EventArgs> Move = delegate { };
         public event EventHandler<EventArgs> Resize = delegate { };
         public event EventHandler<System.ComponentModel.CancelEventArgs> Closing = delegate { };
@@ -118,7 +121,8 @@ namespace OpenTK.Platform.MacOS
         public CocoaNativeWindow(int x, int y, int width, int height, string title, GraphicsMode mode, GameWindowFlags options, DisplayDevice device)
         {
             // Create the window class
-            windowClass = Class.AllocateClass("OpenTKWindow", "NSWindow");
+            Interlocked.Increment(ref UniqueId);
+            windowClass = Class.AllocateClass("OpenTKWindow" + UniqueId, "NSWindow");
             Class.RegisterMethod(windowClass, new WindowDidResizeDelegate(WindowDidResize), "windowDidResize:", "v@:@");
             Class.RegisterMethod(windowClass, new WindowDidMoveDelegate(WindowDidMove), "windowDidMove:", "v@:@");
             Class.RegisterMethod(windowClass, new WindowDidBecomeKeyDelegate(WindowDidBecomeKey), "windowDidBecomeKey:", "v@:@");
@@ -510,7 +514,11 @@ namespace OpenTK.Platform.MacOS
             set
             {
                 icon = value;
-                Cocoa.SendVoid(NSApplication.Handle, selSetApplicationIconImage, Cocoa.ToNSImage(icon.ToBitmap()));
+                using (Image img = icon.ToBitmap())
+                {
+                    IntPtr nsimg = Cocoa.ToNSImage(img);
+                    Cocoa.SendVoid(NSApplication.Handle, selSetApplicationIconImage, nsimg);
+                }
                 IconChanged(this, EventArgs.Empty);
             }
         }