在mac中检测硬件耳机按下

时间:2013-03-13 23:07:40

标签: objective-c cocoa osx-mountain-lion

此问题与此问题的代码有关:Detect headphone button presses in OS X

他们的答案标记正确,但是我无法让他们的代码工作(这可能是因为我缺乏对Objective-c的了解)。我按照他们的指示,修改了三个文件。这就是我的尝试(我也查看了Apple的IOKit文档,找不到任何耳机硬件按钮文档):

AwesomeClass.h

#import <Cocoa/Cocoa.h>
#include "KeyboardPaneController.h"

@interface AwesomeClass : KeyboardPaneController
+ (NSArray *) allKeyboards;
- (void) initKeyboardElements: (NSArray *) elements;
- (void) ddhidQueueHasEvents: (DDHidQueue *) hidQueue;
@end

AwesomeClass.m

#import "AwesomeClass.h"
#import "DDHidLib.h"

@implementation AwesomeClass

+ (NSArray *) allKeyboards;
{
    NSArray *array = [DDHidDevice allDevicesMatchingUsagePage: kHIDPage_Consumer
                                                      usageId: kHIDUsage_GD_Pointer
                                                    withClass: self
                                            skipZeroLocations: NO];

    //Only return "Apple Mikey HID Driver", if not found, return nil.
    for (DDHidDevice *device in array) {
        if ([[device productName] isEqualToString:@"Apple Mikey HID Driver"]) {
            return [NSArray arrayWithObject:device];
        }
    }
    return nil;
}

- (void) initKeyboardElements: (NSArray *) elements;
{
    NSEnumerator * e = [elements objectEnumerator];
    DDHidElement * element;
    while (element = [e nextObject])
    {
        unsigned usagePage = [[element usage] usagePage];
        unsigned usageId = [[element usage] usageId];
        if (usagePage == kHIDPage_GenericDesktop)
        {
            if ((usageId >= 0x89) && (usageId <= 0x8D))
            {
                [mKeyElements addObject: element];
            }
        }
        NSArray * subElements = [element elements];
        if (subElements != nil)
            [self initKeyboardElements: subElements];
    }
}

- (void) ddhidQueueHasEvents: (DDHidQueue *) hidQueue;
{
    DDHidEvent * event;
    while ((event = [hidQueue nextEvent]))
    {
        DDHidElement * element = [self elementForCookie: [event elementCookie]];
        unsigned usageId = [[element usage] usageId];
        SInt32 value = [event value];
        if (value == 1)
            [self ddhidKeyboard: self keyDown: usageId];
    }
}
@end

...以及修改KeyboardPaneController.m中的一行(在说明中显示)。由于缺乏关于框架的文档,很难找到答案(海报已经离线超过一年,所以我假设我可能不会得到回复)。代码在狮子身上进行了测试,我有山狮,所以可能是问题。

我知道这绝对有可能实现,因为iTunes对我的耳机按键按下非常敏感(这有点细微之处)。我希望能够通过耳机上的按钮而不是iTunes来控制Spotify。

1 个答案:

答案 0 :(得分:8)

测试显示它不再作为键盘实现:

    id array = [[DDHidDevice allDevices] filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"productName == \"Apple Mikey HID Driver\""]];
    DDHidDevice *mic = [array count] ? [array objectAtIndex:0] : nil;
    // it isn't a keyboard
    NSLog(@"%@", mic.primaryUsage);
    assert(mic.usage==1 && mic.usagePage==12);

您不能将它视为HIDKeyboard(尝试过,它不会发送按键),也不能将其视为HIDMouse或HID游戏杆。

我挖到HIDQueue类并检查mikey是否会触发任何低级别事件并且它会触发低级别事件!调用queueCallbackFunction(如果您没有过滤特定事件的队列。要过滤它,请参阅DDHidKeyboard中的initWithKeyboardEvents

现在你所要做的就是将低级事件映射到正确的按钮,你就完成了。也许把它全部包装在一个很好的课程中。以下是GitHub上的类和相关代码的示例。