third_party/blink/renderer/platform/geometry/calculation_value.h

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 * in the documentation and/or other materials provided with the
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#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_GEOMETRY_CALCULATION_VALUE_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_GEOMETRY_CALCULATION_VALUE_H_

#include "base/types/pass_key.h"
#include "third_party/blink/renderer/platform/geometry/length.h"
#include "third_party/blink/renderer/platform/geometry/length_functions.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/heap/member.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"

namespace blink {

class CalculationExpressionNode;

class PLATFORM_EXPORT CalculationValue
    : public GarbageCollected<CalculationValue> {
 public:
  CalculationValue(PixelsAndPercent value, Length::ValueRange range)
      : value_(value),
        is_non_negative_(range == Length::ValueRange::kNonNegative) {}

  using PassKey = base::PassKey<CalculationValue>;
  CalculationValue(PassKey,
                   const CalculationExpressionNode* expression,
                   Length::ValueRange range);

  // If |expression| simply wraps a |PixelsAndPercent| value, this function
  // takes that value directly and discards |expression|.
  static const CalculationValue* CreateSimplified(
      const CalculationExpressionNode* expression,
      Length::ValueRange range);

  ~CalculationValue();

  void Trace(Visitor* visitor) const;

  float Evaluate(float max_value, const EvaluationInput& = {}) const;
  bool operator==(const CalculationValue& o) const;
  bool IsExpression() const { return expression_; }
  bool IsNonNegative() const { return is_non_negative_; }
  Length::ValueRange GetValueRange() const {
    return is_non_negative_ ? Length::ValueRange::kNonNegative
                            : Length::ValueRange::kAll;
  }
  bool HasAuto() const;
  bool HasContentOrIntrinsicSize() const;
  bool HasAutoOrContentOrIntrinsicSize() const;
  bool HasPercent() const;
  bool HasPercentOrStretch() const;
  bool HasStretch() const;

  bool HasMinContent() const;
  bool HasMaxContent() const;
  bool HasFitContent() const;

  bool HasOnlyFixedAndPercent() const;

  float Pixels() const {
    DCHECK(!IsExpression());
    return value_.pixels;
  }
  float Percent() const {
    DCHECK(!IsExpression());
    return value_.percent;
  }
  PixelsAndPercent GetPixelsAndPercent() const {
    DCHECK(!IsExpression());
    return value_;
  }
  bool HasExplicitPixels() const {
    DCHECK(!IsExpression());
    return value_.has_explicit_pixels;
  }
  bool HasExplicitPercent() const {
    DCHECK(!IsExpression());
    return value_.has_explicit_percent;
  }

  // If |this| is an expression, returns the underlying expression. Otherwise,
  // creates one from the underlying |PixelsAndPercent| value.
  const CalculationExpressionNode* GetOrCreateExpression() const;

  const CalculationValue* Blend(const CalculationValue& from,
                                double progress,
                                Length::ValueRange) const;
  const CalculationValue* SubtractFromOneHundredPercent() const;
  const CalculationValue* Add(const CalculationValue&) const;
  const CalculationValue* Zoom(double factor) const;

 private:
  // `value_` and `expression_` are mutually exclusive.
  PixelsAndPercent value_;
  Member<const CalculationExpressionNode> expression_ = nullptr;
  const bool is_non_negative_;
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_GEOMETRY_CALCULATION_VALUE_H_