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/*
* Copyright (C) 2025 Samuel Weinig <sam@webkit.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <wtf/Forward.h>
namespace WebCore {
namespace Style {
// Specifies which tracks(s) on the axis that the position-area span occupies.
// Represented as 3 bits: start track, center track, end track.
enum class PositionAreaTrack : uint8_t {
Start = 0b001, // First track.
SpanStart = 0b011, // First and center tracks.
End = 0b100, // Last track.
SpanEnd = 0b110, // Center and last track.
Center = 0b010, // Center track.
SpanAll = 0b111, // All tracks along the axis.
};
constexpr PositionAreaTrack flipPositionAreaTrack(PositionAreaTrack track)
{
// We need to cast values out of the enum type restrictions in order to do math.
auto trackBits = static_cast<uint8_t>(track);
constexpr uint8_t startBit = static_cast<uint8_t>(PositionAreaTrack::Start);
constexpr uint8_t endBit = static_cast<uint8_t>(PositionAreaTrack::End);
constexpr uint8_t sideBits = startBit | endBit;
bool isSymmetric = !(trackBits & startBit) == !(trackBits & endBit);
auto invertedValue = isSymmetric ? trackBits
// Flip side bits and merge with not-side bits.
: ((trackBits & sideBits) ^ sideBits) | (trackBits & ~sideBits);
return static_cast<PositionAreaTrack>(invertedValue);
}
// MARK: - Logging
WTF::TextStream& operator<<(WTF::TextStream&, PositionAreaTrack);
} // namespace Style
} // namespace WebCore
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