| // Copyright 2014 PDFium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com |
| |
| #include "core/fxcrt/fx_bidi.h" |
| |
| #include <algorithm> |
| |
| #include "core/fxcrt/fx_unicode.h" |
| #include "third_party/base/check.h" |
| |
| CFX_BidiChar::CFX_BidiChar() |
| : m_CurrentSegment({0, 0, NEUTRAL}), m_LastSegment({0, 0, NEUTRAL}) {} |
| |
| bool CFX_BidiChar::AppendChar(wchar_t wch) { |
| Direction direction; |
| switch (pdfium::unicode::GetBidiClass(wch)) { |
| case FX_BIDICLASS::kL: |
| case FX_BIDICLASS::kAN: |
| case FX_BIDICLASS::kEN: |
| direction = LEFT; |
| break; |
| case FX_BIDICLASS::kR: |
| case FX_BIDICLASS::kAL: |
| direction = RIGHT; |
| break; |
| default: |
| direction = NEUTRAL; |
| break; |
| } |
| |
| bool bChangeDirection = (direction != m_CurrentSegment.direction); |
| if (bChangeDirection) |
| StartNewSegment(direction); |
| |
| m_CurrentSegment.count++; |
| return bChangeDirection; |
| } |
| |
| bool CFX_BidiChar::EndChar() { |
| StartNewSegment(NEUTRAL); |
| return m_LastSegment.count > 0; |
| } |
| |
| void CFX_BidiChar::StartNewSegment(CFX_BidiChar::Direction direction) { |
| m_LastSegment = m_CurrentSegment; |
| m_CurrentSegment.start += m_CurrentSegment.count; |
| m_CurrentSegment.count = 0; |
| m_CurrentSegment.direction = direction; |
| } |
| |
| CFX_BidiString::CFX_BidiString(const WideString& str) : m_Str(str) { |
| CFX_BidiChar bidi; |
| for (wchar_t c : m_Str) { |
| if (bidi.AppendChar(c)) |
| m_Order.push_back(bidi.GetSegmentInfo()); |
| } |
| if (bidi.EndChar()) |
| m_Order.push_back(bidi.GetSegmentInfo()); |
| |
| size_t nR2L = std::count_if(m_Order.begin(), m_Order.end(), |
| [](const CFX_BidiChar::Segment& seg) { |
| return seg.direction == CFX_BidiChar::RIGHT; |
| }); |
| |
| size_t nL2R = std::count_if(m_Order.begin(), m_Order.end(), |
| [](const CFX_BidiChar::Segment& seg) { |
| return seg.direction == CFX_BidiChar::LEFT; |
| }); |
| |
| if (nR2L > 0 && nR2L >= nL2R) |
| SetOverallDirectionRight(); |
| } |
| |
| CFX_BidiString::~CFX_BidiString() = default; |
| |
| CFX_BidiChar::Direction CFX_BidiString::OverallDirection() const { |
| DCHECK(m_eOverallDirection != CFX_BidiChar::NEUTRAL); |
| return m_eOverallDirection; |
| } |
| |
| void CFX_BidiString::SetOverallDirectionRight() { |
| if (m_eOverallDirection != CFX_BidiChar::RIGHT) { |
| std::reverse(m_Order.begin(), m_Order.end()); |
| m_eOverallDirection = CFX_BidiChar::RIGHT; |
| } |
| } |