flutter_flutter/sky/engine/core/css/CSSCalculationValue.h

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#ifndef SKY_ENGINE_CORE_CSS_CSSCALCULATIONVALUE_H_
#define SKY_ENGINE_CORE_CSS_CSSCALCULATIONVALUE_H_

#include "sky/engine/core/css/CSSPrimitiveValue.h"
#include "sky/engine/core/css/CSSValue.h"
#include "sky/engine/core/css/parser/CSSParserValues.h"
#include "sky/engine/platform/CalculationValue.h"
#include "sky/engine/wtf/PassOwnPtr.h"
#include "sky/engine/wtf/RefCounted.h"
#include "sky/engine/wtf/RefPtr.h"

namespace blink {

class CSSParserValueList;
class CSSValueList;
class CalculationValue;
class CalcExpressionNode;
class Length;

enum CalcOperator {
    CalcAdd = '+',
    CalcSubtract = '-',
    CalcMultiply = '*',
    CalcDivide = '/'
};

// The order of this enum should not change since its elements are used as indices
// in the addSubtractResult matrix.
enum CalculationCategory {
    CalcNumber = 0,
    CalcLength,
    CalcPercent,
    CalcPercentNumber,
    CalcPercentLength,
    CalcAngle,
    CalcTime,
    CalcFrequency,
    CalcOther
};

class CSSCalcExpressionNode : public RefCounted<CSSCalcExpressionNode> {
    DECLARE_EMPTY_VIRTUAL_DESTRUCTOR_WILL_BE_REMOVED(CSSCalcExpressionNode);
public:
    enum Type {
        CssCalcPrimitiveValue = 1,
        CssCalcBinaryOperation
    };

    virtual bool isZero() const = 0;
    virtual double doubleValue() const = 0;
    virtual double computeLengthPx(const CSSToLengthConversionData&) const = 0;
    virtual void accumulateLengthArray(CSSLengthArray&, double multiplier) const = 0;
    virtual void accumulatePixelsAndPercent(const CSSToLengthConversionData&, PixelsAndPercent&, float multiplier = 1) const = 0;
    virtual String customCSSText() const = 0;
    virtual bool equals(const CSSCalcExpressionNode& other) const { return m_category == other.m_category && m_isInteger == other.m_isInteger; }
    virtual Type type() const = 0;

    CalculationCategory category() const { return m_category; }
    virtual CSSPrimitiveValue::UnitType primitiveType() const = 0;
    bool isInteger() const { return m_isInteger; }

protected:
    CSSCalcExpressionNode(CalculationCategory category, bool isInteger)
        : m_category(category)
        , m_isInteger(isInteger)
    {
        ASSERT(category != CalcOther);
    }

    CalculationCategory m_category;
    bool m_isInteger;
};

class CSSCalcValue : public CSSValue {
public:
    static PassRefPtr<CSSCalcValue> create(CSSParserString name, CSSParserValueList*, ValueRange);
    static PassRefPtr<CSSCalcValue> create(PassRefPtr<CSSCalcExpressionNode>, ValueRange = ValueRangeAll);

    static PassRefPtr<CSSCalcExpressionNode> createExpressionNode(PassRefPtr<CSSPrimitiveValue>, bool isInteger = false);
    static PassRefPtr<CSSCalcExpressionNode> createExpressionNode(PassRefPtr<CSSCalcExpressionNode>, PassRefPtr<CSSCalcExpressionNode>, CalcOperator);
    static PassRefPtr<CSSCalcExpressionNode> createExpressionNode(double pixels, double percent);

    PassRefPtr<CalculationValue> toCalcValue(const CSSToLengthConversionData& conversionData) const
    {
        PixelsAndPercent value(0, 0);
        m_expression->accumulatePixelsAndPercent(conversionData, value);
        return CalculationValue::create(value, m_nonNegative ? ValueRangeNonNegative : ValueRangeAll);
    }
    CalculationCategory category() const { return m_expression->category(); }
    bool isInt() const { return m_expression->isInteger(); }
    double doubleValue() const;
    bool isNegative() const { return m_expression->doubleValue() < 0; }
    ValueRange permittedValueRange() { return m_nonNegative ? ValueRangeNonNegative : ValueRangeAll; }
    double computeLengthPx(const CSSToLengthConversionData&) const;
    void accumulateLengthArray(CSSLengthArray& lengthArray, double multiplier) const { m_expression->accumulateLengthArray(lengthArray, multiplier); }
    CSSCalcExpressionNode* expressionNode() const { return m_expression.get(); }

    String customCSSText() const;
    bool equals(const CSSCalcValue&) const;

private:
    CSSCalcValue(PassRefPtr<CSSCalcExpressionNode> expression, ValueRange range)
        : CSSValue(CalculationClass)
        , m_expression(expression)
        , m_nonNegative(range == ValueRangeNonNegative)
    {
    }

    double clampToPermittedRange(double) const;

    const RefPtr<CSSCalcExpressionNode> m_expression;
    const bool m_nonNegative;
};

DEFINE_CSS_VALUE_TYPE_CASTS(CSSCalcValue, isCalcValue());

} // namespace blink


#endif  // SKY_ENGINE_CORE_CSS_CSSCALCULATIONVALUE_H_