#import <objc/runtime.h>

@implementation NSObject (InstanceVariableForKey)
- (void *)instanceVariableForKey:(NSString *)aKey {
    if (aKey) {
        Ivar ivar = object_getInstanceVariable(self, [aKey UTF8String], NULL);
        if (ivar) {
            return (void *)((char *)self + ivar_getOffset(ivar));
        }
    }
    return NULL;
}

@end

typedef struct {
    char itemIsEnabled[23];
    char timeString[64];
    int gsmSignalStrengthRaw;
    int gsmSignalStrengthBars;
    char serviceString[100];
    char serviceCrossfadeString[100];
    char serviceImages[3][100];
    char operatorDirectory[1024];
    unsigned int serviceContentType;
    int wifiSignalStrengthRaw;
    int wifiSignalStrengthBars;
    unsigned int dataNetworkType;
    int batteryCapacity;
    unsigned int batteryState;
    char notChargingString[150];
    int bluetoothBatteryCapacity;
    int thermalColor;
    unsigned int thermalSunlightMode:1;
    unsigned int slowActivity:1;
    unsigned int syncActivity:1;
    char activityDisplayId[256];
    unsigned int bluetoothConnected:1;
    unsigned int displayRawGSMSignal:1;
    unsigned int displayRawWifiSignal:1;
} SbStatusBarDataType;




- (void *) instanceVariableForObject: (id)obj andKey: (NSString *)key {
    if (key != nil) {
        Ivar ivar = object_getInstanceVariable(obj, [key UTF8String], NULL);
        if (ivar) {
            return (void *)((char *)obj + ivar_getOffset(ivar));
        }
    }
    return NULL;
}

SBStatusBarDataManager* mgr = [SBStatusBarDataManager sharedDataManager];
SbStatusBarDataType data = *(SbStatusBarDataType*)[self instanceVariableForObject: mgr andKey: @"_data"];
int signalStrength = data.wifiSignalStrengthRaw;