From 43095307da327e82f136c5fe17d4fdecb3f78cb6 Mon Sep 17 00:00:00 2001
From: Camilla Berglund <elmindreda@elmindreda.org>
Date: Mon, 10 Mar 2014 16:50:20 +0100
Subject: [PATCH] Cleanup of CGDisplayIOServicePort replacement.

---
 README.md           |   1 +
 src/cocoa_monitor.m | 146 ++++++++++++++++++--------------------------
 2 files changed, 59 insertions(+), 88 deletions(-)

diff --git a/README.md b/README.md
index ef57db63..64d5a114 100644
--- a/README.md
+++ b/README.md
@@ -123,6 +123,7 @@ skills.
  - Marcus Geelnard
  - Stefan Gustavson
  - Sylvain Hellegouarch
+ - Matthew Henry
  - heromyth
  - Paul Holden
  - Toni Jovanoski
diff --git a/src/cocoa_monitor.m b/src/cocoa_monitor.m
index a2f9a7f1..ab401ca1 100644
--- a/src/cocoa_monitor.m
+++ b/src/cocoa_monitor.m
@@ -36,110 +36,74 @@
 #include <CoreVideo/CVDisplayLink.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.
+// Returns the name of the specified display
 //
-static io_service_t IOServicePortFromCGDisplayID(CGDirectDisplayID displayID)
+static char* getDisplayName(CGDirectDisplayID displayID)
 {
     io_iterator_t iter;
-    io_service_t serv, servicePort = 0;
-    
+    io_service_t service;
+    char* result = NULL;
+
+    const uint32_t modelNumber = CGDisplayModelNumber(displayID);
+    const uint32_t vendorNumber = CGDisplayVendorNumber(displayID);
+
+    if (modelNumber == kDisplayProductIDGeneric || modelNumber == 0xffffffff ||
+        vendorNumber == kDisplayVendorIDUnknown || vendorNumber == 0xffffffff)
+    {
+        return NULL;
+    }
+
     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;
-        CFNumberRef vendorIDRef, productIDRef;
-        Boolean success;
-        
-        info = IODisplayCreateInfoDictionary(serv,
-                             kIODisplayOnlyPreferredName);
-        
-        vendorIDRef = CFDictionaryGetValue(info,
-                           CFSTR(kDisplayVendorID));
-        productIDRef = CFDictionaryGetValue(info,
-                            CFSTR(kDisplayProductID));
-        
-        success = CFNumberGetValue(vendorIDRef, kCFNumberCFIndexType,
-                                   &vendorID);
-        success &= CFNumberGetValue(productIDRef, kCFNumberCFIndexType,
-                                    &productID);
 
-        if (!success)
+    if (IOServiceGetMatchingServices(kIOMasterPortDefault, matching, &iter) != 0)
+        return NULL;
+
+    while ((service = IOIteratorNext(iter)) != 0)
+    {
+        CFIndex size, vendorID, productID;
+        CFDictionaryRef info, names;
+        CFStringRef name;
+
+        info = IODisplayCreateInfoDictionary(service, kIODisplayOnlyPreferredName);
+
+        CFNumberGetValue(CFDictionaryGetValue(info, CFSTR(kDisplayVendorID)),
+                         kCFNumberCFIndexType, &vendorID);
+        CFNumberGetValue(CFDictionaryGetValue(info, CFSTR(kDisplayProductID)),
+                         kCFNumberCFIndexType, &productID);
+
+        if (vendorNumber != vendorID || modelNumber != productID)
         {
             CFRelease(info);
             continue;
         }
-        
-        if (CGDisplayVendorNumber(displayID) != vendorID ||
-            CGDisplayModelNumber(displayID) != productID)
+
+        names = CFDictionaryGetValue(info, CFSTR(kDisplayProductName));
+        if (!names)
+        {
+            // This may happen if a desktop Mac is running headless
+            CFRelease(info);
+            continue;
+        }
+
+        if (!CFDictionaryGetValueIfPresent(names, CFSTR("en_US"),
+                                           (const void**) &name))
         {
             CFRelease(info);
             continue;
         }
-        
-        // we're a match
-        servicePort = serv;
+
+        size = CFStringGetMaximumSizeForEncoding(CFStringGetLength(name),
+                                                 kCFStringEncodingUTF8);
+        result = calloc(size + 1, sizeof(char));
+        CFStringGetCString(name, result, size, kCFStringEncodingUTF8);
+
         CFRelease(info);
-        break;
     }
-    
+
     IOObjectRelease(iter);
-    return servicePort;
+    return result;
 }
 
-// Get the name of the specified display
-//
-static const char* getDisplayName(CGDirectDisplayID displayID)
-{
-    char* name;
-    CFDictionaryRef info, names;
-    CFStringRef value;
-    CFIndex size;
-    
-    io_service_t serv = IOServicePortFromCGDisplayID(displayID);
-    if (!serv)
-    {
-        return strdup("Unknown");
-    }
-    
-    info = IODisplayCreateInfoDictionary(serv,
-                         kIODisplayOnlyPreferredName);
-    
-    IOObjectRelease(serv);
-    
-    names = CFDictionaryGetValue(info, CFSTR(kDisplayProductName));
-    
-    if (!names || !CFDictionaryGetValueIfPresent(names, CFSTR("en_US"),
-                             (const void**) &value))
-    {
-        // This may happen if a desktop Mac is running headless
-        _glfwInputError(GLFW_PLATFORM_ERROR, "Failed to retrieve display name");
-        CFRelease(info);
-        return strdup("Unknown");
-    }
-    
-    size = CFStringGetMaximumSizeForEncoding(CFStringGetLength(value),
-                         kCFStringEncodingUTF8);
-    name = calloc(size + 1, sizeof(char));
-    CFStringGetCString(value, name, size, kCFStringEncodingUTF8);
-    
-    CFRelease(info);
-    
-    return name;
-}
-
-
 // Check whether the display mode should be included in enumeration
 //
 static GLboolean modeIsGood(CGDisplayModeRef mode)
@@ -332,10 +296,16 @@ _GLFWmonitor** _glfwPlatformGetMonitors(int* count)
     {
         int j;
         const CGSize size = CGDisplayScreenSize(displays[i]);
+        char* name = getDisplayName(displays[i]);
 
-        monitors[found] = _glfwAllocMonitor(getDisplayName(displays[i]),
-                                            size.width, size.height);
+        if (!name)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "Cocoa: Failed to retrieve display name");
+            name = strdup("Unknown");
+        }
 
+        monitors[found] = _glfwAllocMonitor(name, size.width, size.height);
         monitors[found]->ns.displayID = displays[i];
 
         for (j = 0;  j < [screens count];  j++)