Source/WebCore/page/ScrollToOptions.h

/*
 * Copyright (C) 2016 Apple Inc.  All rights reserved.
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 * modification, are permitted provided that the following conditions
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 *
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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#pragma once

#include "ScrollOptions.h"
#include <cmath>
#include <wtf/Optional.h>

namespace WebCore {

struct ScrollToOptions : ScrollOptions {
    Optional<double> left;
    Optional<double> top;

    ScrollToOptions() = default;
    ScrollToOptions(double x, double y)
        : left(x)
        , top(y)
    { }
};

inline double normalizeNonFiniteValueOrFallBackTo(Optional<double> value, double fallbackValue)
{
    // Normalize non-finite values (https://drafts.csswg.org/cssom-view/#normalize-non-finite-values).
    return value ? (std::isfinite(*value) ? *value : 0) : fallbackValue;
}

// FIXME(https://webkit.org/b/88339): Consider using FloatPoint or DoublePoint for fallback and return values.
inline ScrollToOptions normalizeNonFiniteCoordinatesOrFallBackTo(const ScrollToOptions& value, double x, double y)
{
    ScrollToOptions options = value;
    options.left = normalizeNonFiniteValueOrFallBackTo(value.left, x);
    options.top = normalizeNonFiniteValueOrFallBackTo(value.top, y);
    return options;
}

}