Joystick.m

   1 //
   2 //  Joystick.m
   3 //  Enjoy
   4 //
   5 //  Created by Sam McCall on 4/05/09.
   6 //
   7
   8 #import "Joystick.h"
   9
  10 static NSArray *ActionsForElement(IOHIDDeviceRef device, id base) {
  11     CFArrayRef elements = IOHIDDeviceCopyMatchingElements(device, NULL, kIOHIDOptionsTypeNone);
  12     NSMutableArray *children = [NSMutableArray arrayWithCapacity:CFArrayGetCount(elements)];
  13
  14     int buttons = 0;
  15     int axes = 0;
  16
  17     for (int i = 0; i < CFArrayGetCount(elements); i++) {
  18         IOHIDElementRef element = (IOHIDElementRef)CFArrayGetValueAtIndex(elements, i);
  19         int type = IOHIDElementGetType(element);
  20         int usage = IOHIDElementGetUsage(element);
  21         int usagePage = IOHIDElementGetUsagePage(element);
  22         int max = IOHIDElementGetPhysicalMax(element);
  23         int min = IOHIDElementGetPhysicalMin(element);
  24         CFStringRef elName = IOHIDElementGetName(element);
  25
  26         JSAction *action = nil;
  27
  28         if (!(type == kIOHIDElementTypeInput_Misc
  29               || type == kIOHIDElementTypeInput_Axis
  30               || type == kIOHIDElementTypeInput_Button))
  31              continue;
  32
  33         if (max - min == 1 || usagePage == kHIDPage_Button || type == kIOHIDElementTypeInput_Button) {
  34             action = [[JSActionButton alloc] initWithName:(__bridge NSString *)elName
  35                                                       idx:++buttons
  36                                                       max:max];
  37         } else if (usage == kHIDUsage_GD_Hatswitch) {
  38             action = [[JSActionHat alloc] init];
  39         } else if (usage >= kHIDUsage_GD_X && usage <= kHIDUsage_GD_Rz) {
  40             // TODO(jfw): Scaling equation doesn't seem right if min != 0.
  41             action = [[JSActionAnalog alloc] initWithIndex:++axes
  42                                                     offset:-1.f
  43                                                      scale:2.f / (max - min)];
  44         } else {
  45             continue;
  46         }
  47
  48         // TODO(jfw): Should be moved into better constructors.
  49         action.base = base;
  50         action.cookie = IOHIDElementGetCookie(element);
  51         [children addObject:action];
  52     }
  53     return children;
  54 }
  55
  56 @implementation Joystick
  57
  58 @synthesize vendorId;
  59 @synthesize productId;
  60 @synthesize productName;
  61 @synthesize index;
  62 @synthesize device;
  63 @synthesize children;
  64
  65 - (id)initWithDevice:(IOHIDDeviceRef)dev {
  66     if ((self = [super init])) {
  67         self.device = dev;
  68         self.productName = (__bridge NSString *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDProductKey));
  69         self.vendorId = [(__bridge NSNumber *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDVendorIDKey)) intValue];
  70         self.productId = [(__bridge NSNumber *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDProductIDKey)) intValue];
  71         self.children = ActionsForElement(dev, self);
  72     }
  73     return self;
  74 }
  75
  76 - (NSString *)name {
  77     return [NSString stringWithFormat:@"%@ #%d", productName, index];
  78 }
  79
  80 - (id)base {
  81     // FIXME(jfw): This is a hack because actions get joysticks as their base.
  82     return nil;
  83 }
  84
  85 - (NSString *)stringify {
  86     return [[NSString alloc] initWithFormat: @"%d~%d~%d", vendorId, productId, index];
  87 }
  88
  89 - (JSAction *)findActionByCookie:(void *)cookie {
  90     for (JSAction *child in children)
  91         if (child.cookie == cookie)
  92             return child;
  93     return nil;
  94 }
  95
  96 - (id)handlerForEvent:(IOHIDValueRef) value {
  97     JSAction *mainAction = [self actionForEvent:value];
  98     return [mainAction findSubActionForValue:value];
  99 }
 100
 101 - (JSAction *)actionForEvent:(IOHIDValueRef)value {
 102     IOHIDElementRef elt = IOHIDValueGetElement(value);
 103     void *cookie = IOHIDElementGetCookie(elt);
 104     return [self findActionByCookie:cookie];
 105 }
 106
 107 @end