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/*
* Copyright (C) 2000 Lars Knoll (knoll@kde.org)
* Copyright (C) 2003-2017 Apple Inc. All right reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#pragma once
#include <unicode/uchar.h>
#include <wtf/RefPtr.h>
#include <wtf/ThreadSafeRefCounted.h>
namespace WebCore {
enum BidiEmbeddingSource { FromStyleOrDOM, FromUnicode };
// Used to keep track of explicit embeddings.
class BidiContext : public ThreadSafeRefCounted<BidiContext> {
public:
WEBCORE_EXPORT static Ref<BidiContext> create(unsigned char level, UCharDirection, bool override = false, BidiEmbeddingSource = FromStyleOrDOM, BidiContext* parent = nullptr);
BidiContext* parent() const { return m_parent.get(); }
unsigned char level() const { return m_level; }
UCharDirection dir() const { return static_cast<UCharDirection>(m_direction); }
bool override() const { return m_override; }
BidiEmbeddingSource source() const { return static_cast<BidiEmbeddingSource>(m_source); }
WEBCORE_EXPORT Ref<BidiContext> copyStackRemovingUnicodeEmbeddingContexts();
private:
BidiContext(unsigned char level, UCharDirection, bool override, BidiEmbeddingSource, BidiContext* parent);
static Ref<BidiContext> createUncached(unsigned char level, UCharDirection, bool override, BidiEmbeddingSource, BidiContext* parent);
unsigned m_level : 6; // The maximium bidi level is 62: http://unicode.org/reports/tr9/#Explicit_Levels_and_Directions
unsigned m_direction : 5; // Direction
unsigned m_override : 1;
unsigned m_source : 1; // BidiEmbeddingSource
RefPtr<BidiContext> m_parent;
};
inline unsigned char nextGreaterOddLevel(unsigned char level)
{
return (level + 1) | 1;
}
inline unsigned char nextGreaterEvenLevel(unsigned char level)
{
return (level + 2) & ~1;
}
bool operator==(const BidiContext&, const BidiContext&);
} // namespace WebCore
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