1 // Copyright 2014 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6
7 #include "core/fxcrt/fx_bidi.h"
8 #include "core/fxcrt/fx_ucd.h"
9
10 #include <algorithm>
11
CFX_BidiChar()12 CFX_BidiChar::CFX_BidiChar()
13 : m_CurrentSegment({0, 0, NEUTRAL}), m_LastSegment({0, 0, NEUTRAL}) {}
14
AppendChar(FX_WCHAR wch)15 bool CFX_BidiChar::AppendChar(FX_WCHAR wch) {
16 uint32_t dwProps = FX_GetUnicodeProperties(wch);
17 int32_t iBidiCls = (dwProps & FX_BIDICLASSBITSMASK) >> FX_BIDICLASSBITS;
18 Direction direction = NEUTRAL;
19 switch (iBidiCls) {
20 case FX_BIDICLASS_L:
21 case FX_BIDICLASS_AN:
22 case FX_BIDICLASS_EN:
23 direction = LEFT;
24 break;
25 case FX_BIDICLASS_R:
26 case FX_BIDICLASS_AL:
27 direction = RIGHT;
28 break;
29 }
30
31 bool bChangeDirection = (direction != m_CurrentSegment.direction);
32 if (bChangeDirection)
33 StartNewSegment(direction);
34
35 m_CurrentSegment.count++;
36 return bChangeDirection;
37 }
38
EndChar()39 bool CFX_BidiChar::EndChar() {
40 StartNewSegment(NEUTRAL);
41 return m_LastSegment.count > 0;
42 }
43
StartNewSegment(CFX_BidiChar::Direction direction)44 void CFX_BidiChar::StartNewSegment(CFX_BidiChar::Direction direction) {
45 m_LastSegment = m_CurrentSegment;
46 m_CurrentSegment.start += m_CurrentSegment.count;
47 m_CurrentSegment.count = 0;
48 m_CurrentSegment.direction = direction;
49 }
50
CFX_BidiString(const CFX_WideString & str)51 CFX_BidiString::CFX_BidiString(const CFX_WideString& str)
52 : m_Str(str),
53 m_pBidiChar(new CFX_BidiChar),
54 m_eOverallDirection(CFX_BidiChar::LEFT) {
55 for (int i = 0; i < m_Str.GetLength(); ++i) {
56 if (m_pBidiChar->AppendChar(m_Str.GetAt(i)))
57 m_Order.push_back(m_pBidiChar->GetSegmentInfo());
58 }
59 if (m_pBidiChar->EndChar())
60 m_Order.push_back(m_pBidiChar->GetSegmentInfo());
61
62 size_t nR2L = std::count_if(m_Order.begin(), m_Order.end(),
63 [](const CFX_BidiChar::Segment& seg) {
64 return seg.direction == CFX_BidiChar::RIGHT;
65 });
66
67 size_t nL2R = std::count_if(m_Order.begin(), m_Order.end(),
68 [](const CFX_BidiChar::Segment& seg) {
69 return seg.direction == CFX_BidiChar::LEFT;
70 });
71
72 if (nR2L > 0 && nR2L >= nL2R)
73 SetOverallDirectionRight();
74 }
75
~CFX_BidiString()76 CFX_BidiString::~CFX_BidiString() {}
77
SetOverallDirectionRight()78 void CFX_BidiString::SetOverallDirectionRight() {
79 if (m_eOverallDirection != CFX_BidiChar::RIGHT) {
80 std::reverse(m_Order.begin(), m_Order.end());
81 m_eOverallDirection = CFX_BidiChar::RIGHT;
82 }
83 }
84