UILabel and text size for iOS 7

#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 60000
    #define MyLabelAlignmentCenter NSTextAlignmentCenter
#else
    #define MyLabelAlignmentCenter UITextAlignmentCenter
#endif

#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 70000
    #define My_TEXTSIZE(text, font) [text length] > 0 ? [text \
        sizeWithAttributes:@{NSFontAttributeName:font}] : CGSizeZero;
#else
    #define My_TEXTSIZE(text, font) [text length] > 0 ? [text sizeWithFont:font] : CGSizeZero;
#endif

#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 70000
    #define My_MULTILINE_TEXTSIZE(text, font, maxSize, mode) [text length] > 0 ? [text \
        boundingRectWithSize:maxSize options:(NSStringDrawingUsesLineFragmentOrigin) \
        attributes:@{NSFontAttributeName:font} context:nil].size : CGSizeZero;
#else
    #define My_MULTILINE_TEXTSIZE(text, font, maxSize, mode) [text length] > 0 ? [text \
        sizeWithFont:font constrainedToSize:maxSize lineBreakMode:mode] : CGSizeZero;
#endif