mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
105 lines
3.7 KiB
C++
105 lines
3.7 KiB
C++
/*
|
|
* Copyright (C) 2000 Lars Knoll (knoll@kde.org)
|
|
* Copyright (C) 2003, 2004, 2006, 2007, 2009, 2010 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.
|
|
*
|
|
*/
|
|
|
|
#ifndef SKY_ENGINE_PLATFORM_TEXT_BIDICONTEXT_H_
|
|
#define SKY_ENGINE_PLATFORM_TEXT_BIDICONTEXT_H_
|
|
|
|
#include "flutter/sky/engine/platform/PlatformExport.h"
|
|
#include "flutter/sky/engine/wtf/Assertions.h"
|
|
#include "flutter/sky/engine/wtf/PassRefPtr.h"
|
|
#include "flutter/sky/engine/wtf/RefCounted.h"
|
|
#include "flutter/sky/engine/wtf/RefPtr.h"
|
|
#include "flutter/sky/engine/wtf/unicode/Unicode.h"
|
|
|
|
namespace blink {
|
|
|
|
enum BidiEmbeddingSource { FromStyleOrDOM, FromUnicode };
|
|
|
|
// Used to keep track of explicit embeddings.
|
|
class PLATFORM_EXPORT BidiContext : public RefCounted<BidiContext> {
|
|
public:
|
|
static PassRefPtr<BidiContext> create(unsigned char level,
|
|
WTF::Unicode::Direction,
|
|
bool override = false,
|
|
BidiEmbeddingSource = FromStyleOrDOM,
|
|
BidiContext* parent = 0);
|
|
|
|
BidiContext* parent() const { return m_parent.get(); }
|
|
unsigned char level() const { return m_level; }
|
|
WTF::Unicode::Direction dir() const {
|
|
return static_cast<WTF::Unicode::Direction>(m_direction);
|
|
}
|
|
bool override() const { return m_override; }
|
|
BidiEmbeddingSource source() const {
|
|
return static_cast<BidiEmbeddingSource>(m_source);
|
|
}
|
|
|
|
PassRefPtr<BidiContext> copyStackRemovingUnicodeEmbeddingContexts();
|
|
|
|
// http://www.unicode.org/reports/tr9/#Modifications
|
|
// 6.3 raised the limit from 61 to 125.
|
|
// http://unicode.org/reports/tr9/#BD2
|
|
static const unsigned char kMaxLevel = 125;
|
|
|
|
private:
|
|
BidiContext(unsigned char level,
|
|
WTF::Unicode::Direction direction,
|
|
bool override,
|
|
BidiEmbeddingSource source,
|
|
BidiContext* parent)
|
|
: m_level(level),
|
|
m_direction(direction),
|
|
m_override(override),
|
|
m_source(source),
|
|
m_parent(parent) {
|
|
ASSERT(level <= kMaxLevel);
|
|
}
|
|
|
|
static PassRefPtr<BidiContext> createUncached(unsigned char level,
|
|
WTF::Unicode::Direction,
|
|
bool override,
|
|
BidiEmbeddingSource,
|
|
BidiContext* parent);
|
|
|
|
unsigned
|
|
m_level : 7; // The maximium bidi level is 125:
|
|
// 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;
|
|
}
|
|
|
|
PLATFORM_EXPORT bool operator==(const BidiContext&, const BidiContext&);
|
|
|
|
} // namespace blink
|
|
|
|
#endif // SKY_ENGINE_PLATFORM_TEXT_BIDICONTEXT_H_
|