替换已弃用的 NXOpenEventStatus？

Question

我需要获取 OSX 10.13 上鼠标的跟踪速度。我在互联网上找到了这段代码，但 NXOpenEventStatus 已被弃用（IOHIDGetAccelerationWithKey 也是如此），是否有其他方法？

#include <stdio.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/hidsystem/IOHIDLib.h>
#include <IOKit/hidsystem/IOHIDParameter.h>
#include <IOKit/hidsystem/event_status_driver.h>

int main()
{
    kern_return_t kr;
    double trackpadAcceleration, mouseAcceleration;
    NXEventHandle h = 0;

    h = NXOpenEventStatus();

    if (h == nil)
        return -1;


   kr = IOHIDGetAccelerationWithKey( h, CFSTR(kIOHIDMouseAccelerationType), &mouseAcceleration);


   return 0;
}

Answer 1

由于NXOpenEventStatus和IOHIDGetAccelerationWithKey都是开源 IOKit 发行版的一部分，因此您可以查看它们是如何实现的。事实证明，我们可以只使用未弃用的函数来完成这些函数的功能。

为了将其归结为最低限度，您可以获取 HID 系统属性的字典，如下所示：

#import <Foundation/Foundation.h>
#import <IOKit/hidsystem/IOHIDLib.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        io_service_t service = IORegistryEntryFromPath(kIOMasterPortDefault, kIOServicePlane ":/IOResources/IOHIDSystem");

        CFDictionaryRef parameters = IORegistryEntryCreateCFProperty(service, CFSTR(kIOHIDParametersKey), kCFAllocatorDefault, kNilOptions);
        NSLog(@"%@", parameters);

        IOObjectRelease(service);
    }
    return 0;
}

输出（对于 macOS 10.13.4 上的我）：

2018-04-05 17:06:55.560590-0500 accel[11924:131983] {
    ActuateDetents = 1;
    Clicking = 0;
    DragLock = 0;
    Dragging = 0;
    EjectDelay = 0;
    FirstClickThreshold = 1;
    ForceSuppressed = 0;
    HIDClickSpace =     (
        5,
        5
    );
    HIDClickTime = 500000000;
    HIDDefaultParameters = 1;
    HIDF12EjectDelay = 250;
    HIDFKeyMode = 1;
    HIDInitialKeyRepeat = 250000000;
    HIDKeyRepeat = 33333333;
    HIDKeyboardModifierMappingPairs =     (
    );
    HIDMouseAcceleration = 98304;
    HIDMouseKeysOptionToggles = 0;
    HIDPointerAcceleration = 45056;
    HIDPointerButtonMode = 2;
    HIDScrollAcceleration = 20480;
    HIDScrollZoomModifierMask = 262144;
    HIDSlowKeysDelay = 0;
    HIDStickyKeysDisabled = 0;
    HIDStickyKeysOn = 0;
    HIDStickyKeysShiftToggles = 0;
    HIDTrackpadAcceleration = 57344;
    HIDWaitCursorFrameInterval = 16666667;
    JitterNoClick = 1;
    JitterNoMove = 1;
    MouseButtonDivision = 55;
    MouseButtonMode = TwoButton;
    MouseHorizontalScroll = 1;
    MouseMomentumScroll = 1;
    MouseOneFingerDoubleTapGesture = 0;
    MouseTwoFingerDoubleTapGesture = 0;
    MouseTwoFingerHorizSwipeGesture = 0;
    MouseVerticalScroll = 1;
    "OutsidezoneNoAction When Typing" = 1;
    "PalmNoAction Permanent" = 1;
    "PalmNoAction When Typing" = 1;
    SecondClickThreshold = 1;
    "Trackpad Jitter Milliseconds" = 192;
    TrackpadCornerSecondaryClick = 0;
    TrackpadFiveFingerPinchGesture = 0;
    TrackpadFourFingerHorizSwipeGesture = 2;
    TrackpadFourFingerPinchGesture = 0;
    TrackpadFourFingerVertSwipeGesture = 0;
    TrackpadHandResting = 1;
    TrackpadHorizScroll = 1;
    TrackpadMomentumScroll = 1;
    TrackpadPinch = 1;
    TrackpadRightClick = 1;
    TrackpadRotate = 1;
    TrackpadScroll = 1;
    TrackpadThreeFingerDrag = 0;
    TrackpadThreeFingerHorizSwipeGesture = 2;
    TrackpadThreeFingerTapGesture = 0;
    TrackpadThreeFingerVertSwipeGesture = 0;
    TrackpadThreeFingersRightClick = 0;
    TrackpadTwoFingerDoubleTapGesture = 1;
    TrackpadTwoFingerFromRightEdgeSwipeGesture = 0;
    TwofingerNoAction = 1;
    USBMouseStopsTrackpad = 0;
    "Use Panther Settings for W" = 0;
    UserPreferences = 1;
    version = 1;
}
Program ended with exit code: 0

常数kIOHIDMouseAccelerationType有值HIDMouseAcceleration。我也看到了HIDPointerAcceleration，HIDTrackpadAcceleration在那里。kIOHID...这些也有常数。

另请注意，IOHIDGetAccelerationWithKey在返回之前将注册表值除以 65536。IOHIDSetAccelerationWithKey执行相反的变换。