react-native-svg/apple/Text/RNSVGPropHelper.mm

#include "RNSVGPropHelper.h"
@implementation RNSVGPropHelper

+ (CGFloat)fromRelativeWithNSString:(NSString *)length relative:(CGFloat)relative fontSize:(CGFloat)fontSize
{
  length = [length stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
  NSUInteger stringLength = [length length];
  NSInteger percentIndex = stringLength - 1;
  if (stringLength == 0) {
    return 0;
  } else if ([length characterAtIndex:percentIndex] == '%') {
    return (CGFloat)[[length substringWithRange:NSMakeRange(0, percentIndex)] doubleValue] / 100 * relative;
  } else {
    NSInteger twoLetterUnitIndex = stringLength - 2;
    if (twoLetterUnitIndex > 0) {
      NSString *lastTwo = [length substringFromIndex:twoLetterUnitIndex];
      NSUInteger end = twoLetterUnitIndex;
      CGFloat unit = 1;
      if ([lastTwo isEqualToString:@"px"]) {
      } else if ([lastTwo isEqualToString:@"em"]) {
        unit = fontSize;
      } else if ([lastTwo isEqualToString:@"ex"]) {
        unit = fontSize / 2;
      } else if ([lastTwo isEqualToString:@"pt"]) {
        unit = 1.25;
      } else if ([lastTwo isEqualToString:@"pc"]) {
        unit = 15;
      } else if ([lastTwo isEqualToString:@"mm"]) {
        unit = (CGFloat)3.543307;
      } else if ([lastTwo isEqualToString:@"cm"]) {
        unit = (CGFloat)35.43307;
      } else if ([lastTwo isEqualToString:@"in"]) {
        unit = 90;
      } else {
        end = stringLength;
      }

      return (CGFloat)[[length substringWithRange:NSMakeRange(0, end)] doubleValue] * unit;
    } else {
      return (CGFloat)[length doubleValue];
    }
  }
}

+ (CGFloat)fromRelative:(RNSVGLength *)length relative:(CGFloat)relative fontSize:(CGFloat)fontSize
{
  RNSVGLengthUnitType unitType = length.unit;
  CGFloat value = length.value;
  CGFloat unit = 1;
  switch (unitType) {
    case SVG_LENGTHTYPE_NUMBER:
    case SVG_LENGTHTYPE_PX:
      return value;
      break;

    case SVG_LENGTHTYPE_PERCENTAGE:
      return value / 100 * relative;

    case SVG_LENGTHTYPE_EMS:
      unit = fontSize;
      break;
    case SVG_LENGTHTYPE_EXS:
      unit = fontSize / 2;
      break;

    case SVG_LENGTHTYPE_CM:
      unit = (CGFloat)35.43307;
      break;
    case SVG_LENGTHTYPE_MM:
      unit = (CGFloat)3.543307;
      break;
    case SVG_LENGTHTYPE_IN:
      unit = 90;
      break;
    case SVG_LENGTHTYPE_PT:
      unit = 1.25;
      break;
    case SVG_LENGTHTYPE_PC:
      unit = 15;
      break;

    default:
    case SVG_LENGTHTYPE_UNKNOWN:
      return value;
  }
  return value * unit;
}

+ (CGFloat)fromRelative:(RNSVGLength *)length relative:(CGFloat)relative
{
  RNSVGLengthUnitType unitType = length.unit;
  CGFloat value = length.value;
  CGFloat unit = 1;
  switch (unitType) {
    case SVG_LENGTHTYPE_NUMBER:
    case SVG_LENGTHTYPE_PX:
      return value;
      break;

    case SVG_LENGTHTYPE_PERCENTAGE:
      return value / 100 * relative;

    case SVG_LENGTHTYPE_EMS:
      unit = 12;
      break;
    case SVG_LENGTHTYPE_EXS:
      unit = 6;
      break;

    case SVG_LENGTHTYPE_CM:
      unit = (CGFloat)35.43307;
      break;
    case SVG_LENGTHTYPE_MM:
      unit = (CGFloat)3.543307;
      break;
    case SVG_LENGTHTYPE_IN:
      unit = 90;
      break;
    case SVG_LENGTHTYPE_PT:
      unit = 1.25;
      break;
    case SVG_LENGTHTYPE_PC:
      unit = 15;
      break;

    default:
    case SVG_LENGTHTYPE_UNKNOWN:
      return value;
  }
  return value * unit;
}

@end