如何在OSX中点击/挂钩键盘事件并记录哪个键盘触发每个事件

Question

我现在已经发现如何在OS X上以低级别挂机/点击键盘事件:如何在MacBook键盘上点击(挂钩)F7到F12和Power/Eject

从该答案中打印出代码:

// compile and run from the commandline with:
//    clang  -framework coreFoundation  -framework IOKit  ./HID.c  -o hid
//    sudo ./hid

// This code works with the IOHID library to get notified of keys.
//   Still haven't figured out how to truly intercept with
//   substitution.

#include <IOKit/hid/IOHIDValue.h>
#include <IOKit/hid/IOHIDManager.h>

void myHIDKeyboardCallback( void* context,  IOReturn result,  void* sender,  IOHIDValueRef value )
{
    IOHIDElementRef elem = IOHIDValueGetElement( value );

    if (IOHIDElementGetUsagePage(elem) != 0x07)
        return;

    uint32_t scancode = IOHIDElementGetUsage( elem );

    if (scancode < 4 || scancode > 231)
        return;

    long pressed = IOHIDValueGetIntegerValue( value );

    printf( "scancode: %d, pressed: %ld\n", scancode, pressed );
}


CFMutableDictionaryRef myCreateDeviceMatchingDictionary( UInt32 usagePage,  UInt32 usage )
{
    CFMutableDictionaryRef dict = CFDictionaryCreateMutable(
                                                            kCFAllocatorDefault, 0
                                                        , & kCFTypeDictionaryKeyCallBacks
                                                        , & kCFTypeDictionaryValueCallBacks );
    if ( ! dict )
        return NULL;

    CFNumberRef pageNumberRef = CFNumberCreate( kCFAllocatorDefault, kCFNumberIntType, & usagePage );
    if ( ! pageNumberRef ) {
        CFRelease( dict );
        return NULL;
    }

    CFDictionarySetValue( dict, CFSTR(kIOHIDDeviceUsagePageKey), pageNumberRef );
    CFRelease( pageNumberRef );

    CFNumberRef usageNumberRef = CFNumberCreate( kCFAllocatorDefault, kCFNumberIntType, & usage );

    if ( ! usageNumberRef ) {
        CFRelease( dict );
        return NULL;
    }

    CFDictionarySetValue( dict, CFSTR(kIOHIDDeviceUsageKey), usageNumberRef );
    CFRelease( usageNumberRef );

    return dict;
}


int main(void)
{
    IOHIDManagerRef hidManager = IOHIDManagerCreate( kCFAllocatorDefault, kIOHIDOptionsTypeNone );

    CFArrayRef matches;
    {
        CFMutableDictionaryRef keyboard = myCreateDeviceMatchingDictionary( 0x01, 6 );
        CFMutableDictionaryRef keypad   = myCreateDeviceMatchingDictionary( 0x01, 7 );

        CFMutableDictionaryRef matchesList[] = { keyboard, keypad };

        matches = CFArrayCreate( kCFAllocatorDefault, (const void **)matchesList, 2, NULL );
    }

    IOHIDManagerSetDeviceMatchingMultiple( hidManager, matches );

    IOHIDManagerRegisterInputValueCallback( hidManager, myHIDKeyboardCallback, NULL );

    IOHIDManagerScheduleWithRunLoop( hidManager, CFRunLoopGetMain(), kCFRunLoopDefaultMode );

    IOHIDManagerOpen( hidManager, kIOHIDOptionsTypeNone );

    CFRunLoopRun(); // spins
}

我怎样才能(可能调整该代码)识别哪个键盘负责特定事件？

用例是我计划使用外部键盘重新映射,但同时保留内置MacBook键盘的原始映射.

编辑:
辅助键盘的OSX HID过滤器？
https://github.com/candera/khordr/blob/master/src/c/keygrab/hid-scratch.c
http://ianjoker.googlecode.com/svn/trunk/Joker/Joker/hid_test.cpp
http: //www.cplusplusdevelop.com/72_17345226/
http://www.cocoabuilder.com/archive/cocoa/229902-which-keyboard-barcode-scanner-did-the-event-come-from.html

Answer 1

如果您分别在每个感兴趣的设备上注册回调，IOHIDDeviceRegisterInputValueCallback则sender参数将IOHIDDeviceRef指示设备。（而不是使用IOHIDManagerRegisterInputValueCallback发送者将是 HID 管理器引用的位置）

唯一的缺点是您需要注册并处理匹配设备的热插拔事件的通知。（每当新设备出现时注册，当设备消失时注销）

您可以使用IOHIDDeviceCreate()- 这将 anio_service_t作为参数来获取 HID 设备引用。这反过来意味着您需要使用标准 IOKit IOService 匹配函数来获取和监视您的设备列表，但您确实获得了单个设备的显式列表，您可以查询该列表以向用户显示名称等。其关键功能是IOServiceAddMatchingNotification。