ValueUnit.h

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#pragma once

#ifdef RN_SERIALIZABLE_STATE
#include <folly/dynamic.h>
#endif

namespace facebook::react {

enum class UnitType {
  Undefined,
  Point,
  Percent,
};

struct ValueUnit {
  float value{0.0f};
  UnitType unit{UnitType::Undefined};

  ValueUnit() = default;
  ValueUnit(float v, UnitType u) : value(v), unit(u) {}

  bool operator==(const ValueUnit& other) const {
    return value == other.value && unit == other.unit;
  }
  bool operator!=(const ValueUnit& other) const {
    return !(*this == other);
  }

  constexpr float resolve(float referenceLength) const {
    switch (unit) {
      case UnitType::Point:
        return value;
      case UnitType::Percent:
        return value * referenceLength * 0.01f;
      case UnitType::Undefined:
      default:
        return 0.0f;
    }
  }

  constexpr operator bool() const {
    return unit != UnitType::Undefined;
  }

#ifdef RN_SERIALIZABLE_STATE
  folly::dynamic toDynamic() const {
    switch (unit) {
      case UnitType::Undefined:
        return nullptr;
      case UnitType::Point:
        return value;
      case UnitType::Percent:
        return std::format("{}%", value);
    }
  }
#endif
};
} // namespace facebook::react