Getting mouse events from HIDManager in OSX with C++ - c++

Question

I'm porting a game from pc to osx and I'm getting stuck with input events. The main game window is a cocoa app that interfaces with a C++ backend. The pc code uses DirectInput and windows messages to generate keyboard and mouse events that the game understands.
When I first started the port I replaced the windows messages with Carbon event handling, but since discovered that Cocoa apps don't fire off carbon events. I did a bit more reading and discovered the HIDManager which seemed to do what I want and was accessible from c++. Using the information in the post here Using IOHIDManager to Get Modifier Key Events I managed to get keyboard input working, but have so far been unable to extend the example code to generate mouse events as well. The code is have is as follows:
void myHIDCallback(void* context, IOReturn result, void* sender, IOHIDValueRef value)
{
IOHIDElementRef elem = IOHIDValueGetElement(value);
if (IOHIDElementGetUsagePage(elem) == 0x07)
{
// Keyboard events
card32 scancode = IOHIDElementGetUsage(elem);
if (scancode >= 4 && scancode <= 231)
{
long pressed = IOHIDValueGetIntegerValue(value);
KEY_EVENT_DETAILS details = { KEY_EVENT_NONE, NUM_KEYS };
for (card32 n=0; n<NUM_KEYS; ++n)
{
if (n_direct_input_mappings[n].direct_input_key == scancode)
{
details.key_type = n_direct_input_mappings[n].key;
break;
}
}
switch (pressed)
{
case 0:
details.event_type = KEY_EVENT_KEY_DOWN;
break;
case 1:
details.event_type = KEY_EVENT_KEY_UP;
break;
}
sApplication->handle_key_event(details);
}
}
else
if (IOHIDElementGetUsagePage(elem) == 0x02)
{
// Mouse events
card32 usage = IOHIDElementGetUsage(elem);
long pressed = IOHIDValueGetIntegerValue(value);
}
else
{
}
}
CFMutableDictionaryRef myCreateDeviceMatchingDictionary(UInt32 usagePage, UInt32 usage)
{
CFMutableDictionaryRef ret = CFDictionaryCreateMutable(kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
if (ret)
{
CFNumberRef pageNumberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &usagePage);
if (pageNumberRef)
{
CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsagePageKey), pageNumberRef);
CFRelease(pageNumberRef);
CFNumberRef usageNumberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &usage);
if (usageNumberRef)
{
CFDictionarySetValue(ret, CFSTR(kIOHIDDeviceUsageKey), usageNumberRef);
CFRelease(usageNumberRef);
return ret;
}
}
CFRelease(ret);
}
return NULL;
}
bool acquire_hardware_controllers(CA::Application& app, CAWindow& window_handle)
{
sApplication = &app;
// Setup the keyboard event handler
sHIDManager = IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone);
IOHIDManagerOpen(sHIDManager, kIOHIDOptionsTypeNone);
CFMutableDictionaryRef mouse = myCreateDeviceMatchingDictionary(0x01, 2);
CFMutableDictionaryRef keyboard = myCreateDeviceMatchingDictionary(0x01, 6);
CFMutableDictionaryRef keypad = myCreateDeviceMatchingDictionary(0x01, 7);
CFMutableDictionaryRef matchesList[] = {
keyboard,
keypad,
mouse
};
CFArrayRef matches = CFArrayCreate(kCFAllocatorDefault, (const void**)matchesList, 3, NULL);
IOHIDManagerSetDeviceMatchingMultiple(sHIDManager, matches);
IOHIDManagerRegisterInputValueCallback(sHIDManager, myHIDCallback, NULL);
IOHIDManagerScheduleWithRunLoop(sHIDManager, CFRunLoopGetMain(), kCFRunLoopDefaultMode);
}
If anyone can help me out then that would be great. If I can't get this working then I guess I can move over to Cocoa event handling, but the pc code also has some keyboard and mouse polling that I was hoping to implement as well, and I'm not sure that Cocoa supports polling keyboard state - although I will be happy to be corrected.
TIA.