1 /*
2 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
3 * Copyright (C) 2003, 2004, 2006, 2007, 2009, 2010 Apple Inc. All right reserved.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * along with this library; see the file COPYING.LIB. If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 *
20 */
21
22 #ifndef BidiContext_h
23 #define BidiContext_h
24
25 #include <wtf/Assertions.h>
26 #include <wtf/PassRefPtr.h>
27 #include <wtf/RefCounted.h>
28 #include <wtf/RefPtr.h>
29 #include <wtf/unicode/Unicode.h>
30
31 namespace WebCore {
32
33 enum BidiEmbeddingSource {
34 FromStyleOrDOM,
35 FromUnicode
36 };
37
38 // Used to keep track of explicit embeddings.
39 class BidiContext : public RefCounted<BidiContext> {
40 public:
41 static PassRefPtr<BidiContext> create(unsigned char level, WTF::Unicode::Direction, bool override = false, BidiEmbeddingSource = FromStyleOrDOM, BidiContext* parent = 0);
42
parent()43 BidiContext* parent() const { return m_parent.get(); }
level()44 unsigned char level() const { return m_level; }
dir()45 WTF::Unicode::Direction dir() const { return static_cast<WTF::Unicode::Direction>(m_direction); }
override()46 bool override() const { return m_override; }
source()47 BidiEmbeddingSource source() const { return static_cast<BidiEmbeddingSource>(m_source); }
48
49 PassRefPtr<BidiContext> copyStackRemovingUnicodeEmbeddingContexts();
50 private:
BidiContext(unsigned char level,WTF::Unicode::Direction direction,bool override,BidiEmbeddingSource source,BidiContext * parent)51 BidiContext(unsigned char level, WTF::Unicode::Direction direction, bool override, BidiEmbeddingSource source, BidiContext* parent)
52 : m_level(level)
53 , m_direction(direction)
54 , m_override(override)
55 , m_source(source)
56 , m_parent(parent)
57 {
58 }
59
60 static PassRefPtr<BidiContext> createUncached(unsigned char level, WTF::Unicode::Direction, bool override, BidiEmbeddingSource, BidiContext* parent);
61
62 unsigned char m_level;
63 unsigned m_direction : 5; // Direction
64 bool m_override : 1;
65 unsigned m_source : 1; // BidiEmbeddingSource
66 RefPtr<BidiContext> m_parent;
67 };
68
nextGreaterOddLevel(unsigned char level)69 inline unsigned char nextGreaterOddLevel(unsigned char level)
70 {
71 return (level + 1) | 1;
72 }
73
nextGreaterEvenLevel(unsigned char level)74 inline unsigned char nextGreaterEvenLevel(unsigned char level)
75 {
76 return (level + 2) & ~1;
77 }
78
79 bool operator==(const BidiContext&, const BidiContext&);
80
81 } // namespace WebCore
82
83 #endif // BidiContext_h
84