Setup listening for window events.

Source/OpenTK/Platform/MacOS/Cocoa/Class.cs

@@ -5,9 +5,21 @@ namespace OpenTK.Platform.MacOS
 {
     static class Class
     {
+        [DllImport (Cocoa.LibObjC)]
+        extern static IntPtr class_getName(IntPtr handle);
+
+        [DllImport (Cocoa.LibObjC)]
+        extern static bool class_addMethod(IntPtr classHandle, IntPtr selector, IntPtr method, string types);
+
         [DllImport (Cocoa.LibObjC)]
         extern static IntPtr objc_getClass(string name);
 
+        [DllImport (Cocoa.LibObjC)]
+        extern static IntPtr objc_allocateClassPair(IntPtr parentClass, string name, int extraBytes);
+
+        [DllImport (Cocoa.LibObjC)]
+        extern static void objc_registerClassPair(IntPtr classToRegister);
+
         public static IntPtr Get(string name)
         {
             var id = objc_getClass(name);
@@ -17,5 +29,29 @@ namespace OpenTK.Platform.MacOS
             }
             return id;
         }
+
+        public static IntPtr AllocateClass(string className, string parentClass)
+        {
+            return objc_allocateClassPair(Get(parentClass), className, 0);
+        }
+
+        public static void RegisterClass(IntPtr handle)
+        {
+            objc_registerClassPair(handle);
+        }
+
+        public static void RegisterMethod(IntPtr handle, Delegate d, string selector, string typeString)
+        {
+            // TypeString info:
+            // https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtTypeEncodings.html
+
+            IntPtr p = Marshal.GetFunctionPointerForDelegate(d);
+            bool r = class_addMethod(handle, Selector.Get(selector), p, typeString);
+
+            if (!r)
+            {
+                throw new ArgumentException("Could not register method " + d + " in class + " + class_getName(handle));
+            }
+        }
     }
 }

Source/OpenTK/Platform/MacOS/CocoaNativeWindow.cs

@@ -1,5 +1,6 @@
 using System;
 using OpenTK.Graphics;
+using System.Drawing;
 
 namespace OpenTK.Platform.MacOS
 {
@@ -22,8 +23,6 @@ namespace OpenTK.Platform.MacOS
         public event System.EventHandler<System.EventArgs> MouseLeave;
         public event System.EventHandler<System.EventArgs> MouseEnter;
 
-        private CocoaWindowInfo windowInfo;
-
         static readonly IntPtr nextEventMatchingMask = Selector.Get("nextEventMatchingMask:untilDate:inMode:dequeue:");
         static readonly IntPtr sendEvent = Selector.Get("sendEvent:");
         static readonly IntPtr updateWindows = Selector.Get("updateWindows");
@@ -36,17 +35,28 @@ namespace OpenTK.Platform.MacOS
             NSDefaultRunLoopMode = Cocoa.GetStringConstant(Cocoa.FoundationLibrary, "NSDefaultRunLoopMode");
         }
 
+        private CocoaWindowInfo windowInfo;
+        private IntPtr windowClass;
+
         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");
+            Class.RegisterMethod(windowClass, new WindowDidResizeDelegate(WindowDidResize), "windowDidResize:", "v@:@");
+            Class.RegisterClass(windowClass);
+
+            // Create window instance
             var contentRect = new System.Drawing.RectangleF(x, y, width, height);
             var style = NSWindowStyle.Titled | NSWindowStyle.Resizable;
             var bufferingType = NSBackingStore.Buffered;
 
             IntPtr windowPtr;
-            windowPtr = Cocoa.SendIntPtr(Class.Get("NSWindow"), Selector.Alloc);
+            windowPtr = Cocoa.SendIntPtr(windowClass, Selector.Alloc);
             windowPtr = Cocoa.SendIntPtr(windowPtr, Selector.Get("initWithContentRect:styleMask:backing:defer:"), contentRect, (int)style, (int)bufferingType, false);
             windowPtr = Cocoa.SendIntPtr(windowPtr, Selector.Autorelease);
 
+            // Set up behavior
+            Cocoa.SendIntPtr(windowPtr, Selector.Get("setDelegate:"), windowPtr); // The window class acts as its own delegate 
             Cocoa.SendVoid(windowPtr, Selector.Get("cascadeTopLeftFromPoint:"), new System.Drawing.PointF(20, 20));
             Cocoa.SendVoid(windowPtr, Selector.Get("setTitle:"), Cocoa.ToNative(title));
             Cocoa.SendVoid(windowPtr, Selector.Get("makeKeyAndOrderFront:"), IntPtr.Zero);
@@ -54,6 +64,13 @@ namespace OpenTK.Platform.MacOS
             windowInfo = new CocoaWindowInfo(windowPtr);
         }
 
+        delegate void WindowDidResizeDelegate(IntPtr self, IntPtr cmd, IntPtr notification);
+
+        void WindowDidResize(IntPtr self, IntPtr cmd, IntPtr notification)
+        {
+            GraphicsContext.CurrentContext.Update(windowInfo);
+        }
+
         public static IntPtr GetView(IntPtr windowHandle)
         {
             return Cocoa.SendIntPtr(windowHandle, contentView);