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 *
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 * in the documentation and/or other materials provided with the
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#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_ANIMATION_ANIMATABLE_ANIMATABLE_VALUE_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_ANIMATION_ANIMATABLE_ANIMATABLE_VALUE_H_

#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/css/css_value.h"
#include "third_party/blink/renderer/platform/heap/handle.h"

namespace blink {

class CORE_EXPORT AnimatableValue
    : public GarbageCollectedFinalized<AnimatableValue> {
 public:
  virtual ~AnimatableValue() = default;

  static AnimatableValue* Interpolate(const AnimatableValue*,
                                      const AnimatableValue*,
                                      double fraction);
  bool IsDouble() const { return GetType() == kTypeDouble; }
  bool IsFilterOperations() const { return GetType() == kTypeFilterOperations; }
  bool IsTransform() const { return GetType() == kTypeTransform; }
  bool IsUnknown() const { return GetType() == kTypeUnknown; }

  bool IsSameType(const AnimatableValue* value) const {
    DCHECK(value);
    return value->GetType() == GetType();
  }

  virtual void Trace(Visitor*) {}

 protected:
  enum AnimatableType {
    kTypeDouble,
    kTypeFilterOperations,
    kTypeTransform,
    kTypeUnknown,
  };

  virtual AnimatableValue* InterpolateTo(const AnimatableValue*,
                                         double fraction) const {
    NOTREACHED();
    return nullptr;
  }
  static AnimatableValue* DefaultInterpolateTo(const AnimatableValue* left,
                                               const AnimatableValue* right,
                                               double fraction) {
    return const_cast<AnimatableValue*>((fraction < 0.5) ? left : right);
  }

 private:
  virtual AnimatableType GetType() const = 0;

  template <class Keyframe>
  friend class KeyframeEffectModel;
};

#define DEFINE_ANIMATABLE_VALUE_TYPE_CASTS(thisType, predicate)         \
  DEFINE_TYPE_CASTS(thisType, AnimatableValue, value, value->predicate, \
                    value.predicate)

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_ANIMATION_ANIMATABLE_ANIMATABLE_VALUE_H_