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 #import "JSAction.h"
  11 #import "JSActionAnalog.h"
  12 #import "JSActionButton.h"
  13 #import "JSActionHat.h"
  14
  15 static NSArray *ActionsForElement(IOHIDDeviceRef device, id base) {
  16     CFArrayRef elements = IOHIDDeviceCopyMatchingElements(device, NULL, kIOHIDOptionsTypeNone);
  17     NSMutableArray *children = [NSMutableArray arrayWithCapacity:CFArrayGetCount(elements)];
  18
  19     int buttons = 0;
  20     int axes = 0;
  21     int hats = 0;
  22
  23     for (int i = 0; i < CFArrayGetCount(elements); i++) {
  24         IOHIDElementRef element = (IOHIDElementRef)CFArrayGetValueAtIndex(elements, i);
  25         int type = IOHIDElementGetType(element);
  26         int usage = IOHIDElementGetUsage(element);
  27         int usagePage = IOHIDElementGetUsagePage(element);
  28         int max = IOHIDElementGetPhysicalMax(element);
  29         int min = IOHIDElementGetPhysicalMin(element);
  30         CFStringRef elName = IOHIDElementGetName(element);
  31
  32         JSAction *action = nil;
  33
  34         if (!(type == kIOHIDElementTypeInput_Misc
  35               || type == kIOHIDElementTypeInput_Axis
  36               || type == kIOHIDElementTypeInput_Button))
  37              continue;
  38
  39         if (max - min == 1 || usagePage == kHIDPage_Button || type == kIOHIDElementTypeInput_Button) {
  40             action = [[JSActionButton alloc] initWithName:(__bridge NSString *)elName
  41                                                       idx:++buttons
  42                                                       max:max];
  43         } else if (usage == kHIDUsage_GD_Hatswitch) {
  44             action = [[JSActionHat alloc] initWithIndex:++hats];
  45         } else if (usage >= kHIDUsage_GD_X && usage <= kHIDUsage_GD_Rz) {
  46             // TODO(jfw): Scaling equation doesn't seem right if min != 0.
  47             action = [[JSActionAnalog alloc] initWithIndex:++axes
  48                                                     offset:-1.f
  49                                                      scale:2.f / (max - min)];
  50         } else {
  51             continue;
  52         }
  53
  54         // TODO(jfw): Should be moved into better constructors.
  55         action.base = base;
  56         action.cookie = IOHIDElementGetCookie(element);
  57         [children addObject:action];
  58     }
  59     return children;
  60 }
  61
  62 @implementation Joystick
  63
  64 @synthesize vendorId;
  65 @synthesize productId;
  66 @synthesize productName;
  67 @synthesize index;
  68 @synthesize device;
  69 @synthesize children;
  70
  71 - (id)initWithDevice:(IOHIDDeviceRef)dev {
  72     if ((self = [super init])) {
  73         self.device = dev;
  74         self.productName = (__bridge NSString *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDProductKey));
  75         self.vendorId = [(__bridge NSNumber *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDVendorIDKey)) intValue];
  76         self.productId = [(__bridge NSNumber *)IOHIDDeviceGetProperty(dev, CFSTR(kIOHIDProductIDKey)) intValue];
  77         self.children = ActionsForElement(dev, self);
  78     }
  79     return self;
  80 }
  81
  82 - (NSString *)name {
  83     return [NSString stringWithFormat:@"%@ #%d", productName, index];
  84 }
  85
  86 - (id)base {
  87     return nil;
  88 }
  89
  90 - (NSString *)uid {
  91     return [NSString stringWithFormat: @"%d:%d:%d", vendorId, productId, index];
  92 }
  93
  94 - (JSAction *)findActionByCookie:(void *)cookie {
  95     for (JSAction *child in children)
  96         if (child.cookie == cookie)
  97             return child;
  98     return nil;
  99 }
 100
 101 - (id)handlerForEvent:(IOHIDValueRef) value {
 102     JSAction *mainAction = [self actionForEvent:value];
 103     return [mainAction findSubActionForValue:value];
 104 }
 105
 106 - (JSAction *)actionForEvent:(IOHIDValueRef)value {
 107     IOHIDElementRef elt = IOHIDValueGetElement(value);
 108     void *cookie = IOHIDElementGetCookie(elt);
 109     return [self findActionByCookie:cookie];
 110 }
 111
 112 @end