Joystick.m

   1 //
   2 //  Joystick.m
   3 //  Enjoy
   4 //
   5 //  Created by Sam McCall on 4/05/09.
   6 //
   7
   8 static NSArray *ActionsForElement(IOHIDDeviceRef device, id base) {
   9     CFArrayRef elements = IOHIDDeviceCopyMatchingElements(device, NULL, kIOHIDOptionsTypeNone);
  10     NSMutableArray *children = [NSMutableArray arrayWithCapacity:CFArrayGetCount(elements)];
  11
  12     int buttons = 0;
  13     int axes = 0;
  14
  15     for (int i = 0; i < CFArrayGetCount(elements); i++) {
  16         IOHIDElementRef element = (IOHIDElementRef)CFArrayGetValueAtIndex(elements, i);
  17         int type = IOHIDElementGetType(element);
  18         int usage = IOHIDElementGetUsage(element);
  19         int usagePage = IOHIDElementGetUsagePage(element);
  20         int max = IOHIDElementGetPhysicalMax(element);
  21         int min = IOHIDElementGetPhysicalMin(element);
  22         CFStringRef elName = IOHIDElementGetName(element);
  23
  24         JSAction *action = NULL;
  25
  26         if(!(type == kIOHIDElementTypeInput_Misc
  27              || type == kIOHIDElementTypeInput_Axis
  28              || type == kIOHIDElementTypeInput_Button))
  29             continue;
  30
  31         if (max - min == 1 || usagePage == kHIDPage_Button || type == kIOHIDElementTypeInput_Button) {
  32             action = [[JSActionButton alloc] initWithIndex:buttons++ andName:(__bridge NSString *)elName];
  33             [(JSActionButton*)action setMax:max];
  34         } else if (usage == kHIDUsage_GD_Hatswitch) {
  35             action = [[JSActionHat alloc] init];
  36         } else {
  37             if (usage >= kHIDUsage_GD_X && usage <= kHIDUsage_GD_Rz) {
  38                 action = [[JSActionAnalog alloc] initWithIndex: axes++];
  39                 [(JSActionAnalog*)action setOffset:(double)-1.0];
  40                 [(JSActionAnalog*)action setScale:(double)2.0/(max - min)];
  41             } else
  42                 continue;
  43         }
  44
  45         [action setBase:base];
  46         [action setUsage:usage];
  47         [action setCookie:IOHIDElementGetCookie(element)];
  48         [children addObject:action];
  49     }
  50     return children;
  51 }
  52
  53 @implementation Joystick
  54
  55 @synthesize vendorId;
  56 @synthesize productId;
  57 @synthesize productName;
  58 @synthesize index;
  59 @synthesize device;
  60 @synthesize children;
  61
  62 - (id)initWithDevice:(IOHIDDeviceRef)dev {
  63     if ((self = [super init])) {
  64         self.device = dev;
  65         self.productName = (__bridge NSString *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDProductKey));
  66         self.vendorId = [(__bridge NSNumber *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDVendorIDKey)) intValue];
  67         self.productId = [(__bridge NSNumber *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDProductIDKey)) intValue];
  68         self.children = ActionsForElement(dev, self);
  69     }
  70     return self;
  71 }
  72
  73 - (NSString *)name {
  74     return [NSString stringWithFormat:@"%@ #%d", productName, index + 1];
  75 }
  76
  77 - (id)base {
  78     // FIXME(jfw): This is a hack because actions get joysticks as their base.
  79     return nil;
  80 }
  81
  82 - (NSString *)stringify {
  83     return [[NSString alloc] initWithFormat: @"%d~%d~%d", vendorId, productId, index];
  84 }
  85
  86 - (JSAction *)findActionByCookie:(void *)cookie {
  87     for (JSAction *child in children)
  88         if (child.cookie == cookie)
  89             return child;
  90     return nil;
  91 }
  92
  93 - (id)handlerForEvent:(IOHIDValueRef) value {
  94     JSAction *mainAction = [self actionForEvent:value];
  95     return [mainAction findSubActionForValue:value];
  96 }
  97
  98 - (JSAction *)actionForEvent:(IOHIDValueRef)value {
  99     IOHIDElementRef elt = IOHIDValueGetElement(value);
 100     void *cookie = IOHIDElementGetCookie(elt);
 101     return [self findActionByCookie:cookie];
 102 }
 103
 104 @end