Source/WebCore/platform/CalculationValue.cpp

/*
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 * Copyright (C) 2014 Apple Inc. All rights reserved.
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#include "config.h"
#include "CalculationValue.h"

#include <limits>

namespace WebCore {

Ref<CalculationValue> CalculationValue::create(std::unique_ptr<CalcExpressionNode> value, ValueRange range)
{
    return adoptRef(*new CalculationValue(WTFMove(value), range));
}

float CalcExpressionNumber::evaluate(float) const
{
    return m_value;
}

bool CalcExpressionNumber::operator==(const CalcExpressionNode& other) const
{
    return other.type() == CalcExpressionNodeNumber && *this == toCalcExpressionNumber(other);
}

float CalculationValue::evaluate(float maxValue) const
{
    float result = m_expression->evaluate(maxValue);
    // FIXME: This test was originally needed when we did not detect division by zero at parse time.
    // It's possible that this is now unneeded code and can be removed.
    if (std::isnan(result))
        return 0;
    return m_shouldClampToNonNegative && result < 0 ? 0 : result;
}

float CalcExpressionBinaryOperation::evaluate(float maxValue) const
{
    float left = m_leftSide->evaluate(maxValue);
    float right = m_rightSide->evaluate(maxValue);
    switch (m_operator) {
    case CalcAdd:
        return left + right;
    case CalcSubtract:
        return left - right;
    case CalcMultiply:
        return left * right;
    case CalcDivide:
        if (!right)
            return std::numeric_limits<float>::quiet_NaN();
        return left / right;
    }
    ASSERT_NOT_REACHED();
    return std::numeric_limits<float>::quiet_NaN();
}

bool CalcExpressionBinaryOperation::operator==(const CalcExpressionNode& other) const
{
    return other.type() == CalcExpressionNodeBinaryOperation && *this == toCalcExpressionBinaryOperation(other);
}

float CalcExpressionLength::evaluate(float maxValue) const
{
    return floatValueForLength(m_length, maxValue);
}

bool CalcExpressionLength::operator==(const CalcExpressionNode& other) const
{
    return other.type() == CalcExpressionNodeLength && *this == toCalcExpressionLength(other);
}

float CalcExpressionBlendLength::evaluate(float maxValue) const
{
    return (1.0f - m_progress) * floatValueForLength(m_from, maxValue) + m_progress * floatValueForLength(m_to, maxValue);
}

bool CalcExpressionBlendLength::operator==(const CalcExpressionNode& other) const
{
    return other.type() == CalcExpressionNodeBlendLength && *this == toCalcExpressionBlendLength(other);
}

} // namespace WebCore