Fixed Deprecated CGDisplayIOServicePort

*A function has manually been created that deals with grabbing the approriate service_io port.
*This function adds support for collision detection against the VendorID, ProductID, and the SerialNumber. The serial number check is required incase a user has two types of identical monitors.
*Supports OS X 10.4 (Tiger) and Newer (Untested, based on API Docs)
I would like to give special thanks to mhernr18 for providing the initial code.
Recloses #165

include/GLFW/glfw3native.h

@@ -56,6 +56,7 @@ extern "C" {
  *  The available context API macros are:
  *  * `GLFW_EXPOSE_NATIVE_WGL`
  *  * `GLFW_EXPOSE_NATIVE_NSGL`
+ *  * `GLFW_EXPOSE_NATIVE_CGL`
  *  * `GLFW_EXPOSE_NATIVE_GLX`
  *  * `GLFW_EXPOSE_NATIVE_EGL`
  *
@@ -94,6 +95,8 @@ extern "C" {
  /* WGL is declared by windows.h */
 #elif defined(GLFW_EXPOSE_NATIVE_NSGL)
  /* NSGL is declared by Cocoa.h */
+#elif defined(GLFW_EXPOSE_NATIVE_CGL)
+ #include <OpenGL/OpenGL.h>
 #elif defined(GLFW_EXPOSE_NATIVE_GLX)
  #include <GL/glx.h>
 #elif defined(GLFW_EXPOSE_NATIVE_EGL)
@@ -221,6 +224,14 @@ GLFWAPI id glfwGetCocoaWindow(GLFWwindow* window);
  */
 GLFWAPI id glfwGetNSGLContext(GLFWwindow* window);
 #endif
+    
+#if defined(GLFW_EXPOSE_NATIVE_CGL)
+    /*! @brief Returns the `CGLContextObj` of the specified window.
+     *  @return The `CGLContextObj` of the specified window.
+     *  @ingroup native
+     */
+    GLFWAPI CGLContextObj glfwGetCGLContext(GLFWwindow* window);
+#endif
 
 #if defined(GLFW_EXPOSE_NATIVE_X11)
 /*! @brief Returns the `Display` used by GLFW.

src/cocoa_monitor.m

@@ -38,6 +38,76 @@
 #include <ApplicationServices/ApplicationServices.h>
 
 
+// Returns the io_service_t corresponding to a CG display ID, or 0 on failure.
+// The io_service_t should be released with IOObjectRelease when not needed.
+//
+static io_service_t IOServicePortFromCGDisplayID(CGDirectDisplayID displayID)
+{
+    io_iterator_t iter;
+    io_service_t serv, servicePort = 0;
+    
+    CFMutableDictionaryRef matching = IOServiceMatching("IODisplayConnect");
+    
+    // releases matching for us
+    kern_return_t err = IOServiceGetMatchingServices(kIOMasterPortDefault,
+                                                     matching,
+                                                     &iter);
+    if (err)
+        return 0;
+    
+    while ((serv = IOIteratorNext(iter)) != 0)
+    {
+        CFDictionaryRef info;
+        CFIndex vendorID, productID, serialNumber;
+        CFNumberRef vendorIDRef, productIDRef, serialNumberRef;
+        Boolean success;
+        
+        info = IODisplayCreateInfoDictionary(serv,
+                                             kIODisplayOnlyPreferredName);
+        
+        vendorIDRef = CFDictionaryGetValue(info,
+                                           CFSTR(kDisplayVendorID));
+        productIDRef = CFDictionaryGetValue(info,
+                                            CFSTR(kDisplayProductID));
+        serialNumberRef = CFDictionaryGetValue(info,
+                                               CFSTR(kDisplaySerialNumber));
+        
+        success = CFNumberGetValue(vendorIDRef, kCFNumberCFIndexType,
+                                   &vendorID);
+        success &= CFNumberGetValue(productIDRef, kCFNumberCFIndexType,
+                                    &productID);
+        success &= CFNumberGetValue(serialNumberRef, kCFNumberCFIndexType,
+                                    &serialNumber);
+        
+        if (!success)
+        {
+            CFRelease(info);
+            continue;
+        }
+        
+        // If the vendor and product id along with the serial don't match
+        // then we are not looking at the correct monitor.
+        // NOTE: The serial number is important in cases where two monitors
+        //       are the exact same.
+        if (CGDisplayVendorNumber(displayID) != vendorID  ||
+            CGDisplayModelNumber(displayID) != productID  ||
+            CGDisplaySerialNumber(displayID) != serialNumber)
+        {
+            CFRelease(info);
+            continue;
+        }
+        
+        // The VendorID, Product ID, and the Serial Number all Match Up!
+        // Therefore we have found the appropriate display io_service
+        servicePort = serv;
+        CFRelease(info);
+        break;
+    }
+    
+    IOObjectRelease(iter);
+    return servicePort;
+}
+
 // Get the name of the specified display
 //
 static char* getDisplayName(CGDirectDisplayID displayID)
@@ -47,10 +117,18 @@ static char* getDisplayName(CGDirectDisplayID displayID)
     CFStringRef value;
     CFIndex size;
 
-    // NOTE: This uses a deprecated function because Apple has
+    // Supports OS X 10.4 Tiger and Newer
-    //       (as of January 2015) not provided any alternative
+    io_service_t serv = IOServicePortFromCGDisplayID(displayID);
-    info = IODisplayCreateInfoDictionary(CGDisplayIOServicePort(displayID),
+    if (serv == 0)
-                                         kIODisplayOnlyPreferredName);
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Cocoa: IOServicePortFromCGDisplayID Returned an Invalid Port. (Port: 0)");
+        return strdup("Unknown");
+    }
+
+    info = IODisplayCreateInfoDictionary(serv, kIODisplayOnlyPreferredName);
+    IOObjectRelease(serv);
+    
     names = CFDictionaryGetValue(info, CFSTR(kDisplayProductName));
 
     if (!names || !CFDictionaryGetValueIfPresent(names, CFSTR("en_US"),

src/nsgl_context.m

@@ -306,3 +306,8 @@ GLFWAPI id glfwGetNSGLContext(GLFWwindow* handle)
     return window->nsgl.context;
 }
 
+GLFWAPI CGLContextObj glfwGetCGLContext(GLFWwindow* handle)
+{
+    NSOpenGLContext* ctx = glfwGetNSGLContext(handle);
+    return [ctx CGLContextObj];
+}