third_party/WebKit/Source/core/animation/LengthUnitsChecker.h

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef LengthUnitsChecker_h
#define LengthUnitsChecker_h

#include "core/animation/InterpolationType.h"
#include "core/css/CSSPrimitiveValue.h"
#include "core/css/resolver/StyleResolverState.h"
#include "wtf/PtrUtil.h"
#include <memory>

namespace blink {

class LengthUnitsChecker : public InterpolationType::ConversionChecker {
 public:
  static std::unique_ptr<LengthUnitsChecker> maybeCreate(
      CSSLengthArray&& lengthArray,
      const StyleResolverState& state) {
    bool create = false;
    size_t lastIndex = 0;
    for (size_t i = 0; i < lengthArray.values.size(); i++) {
      if (i == CSSPrimitiveValue::UnitTypePercentage ||
          !lengthArray.typeFlags.get(i))
        continue;
      lengthArray.values[i] = lengthUnit(i, state.cssToLengthConversionData());
      create = true;
      lastIndex = i;
    }
    if (!create)
      return nullptr;
    return WTF::wrapUnique(
        new LengthUnitsChecker(std::move(lengthArray), lastIndex));
  }

  bool isValid(const InterpolationEnvironment& environment,
               const InterpolationValue& underlying) const final {
    for (size_t i = 0; i <= m_lastIndex; i++) {
      if (i == CSSPrimitiveValue::UnitTypePercentage ||
          !m_lengthArray.typeFlags.get(i))
        continue;
      if (m_lengthArray.values[i] !=
          lengthUnit(i, environment.state().cssToLengthConversionData()))
        return false;
    }
    return true;
  }

  static double lengthUnit(size_t lengthUnitType,
                           const CSSToLengthConversionData& conversionData) {
    return conversionData.zoomedComputedPixels(
        1, CSSPrimitiveValue::lengthUnitTypeToUnitType(
               static_cast<CSSPrimitiveValue::LengthUnitType>(lengthUnitType)));
  }

 private:
  LengthUnitsChecker(CSSPrimitiveValue::CSSLengthArray&& lengthArray,
                     size_t lastIndex)
      : m_lengthArray(std::move(lengthArray)), m_lastIndex(lastIndex) {}

  const CSSLengthArray m_lengthArray;
  const size_t m_lastIndex;
};

}  // namespace blink

#endif  // LengthUnitsChecker_h