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