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// Copyright 2014 The PDFium Authors
// 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_op.h"
CFX_BidiChar::CFX_BidiChar()
: m_CurrentSegment({0, 0, Direction::kNeutral}),
m_LastSegment({0, 0, Direction::kNeutral}) {}
bool CFX_BidiChar::AppendChar(wchar_t wch) {
Direction direction;
switch (pdfium::unicode::GetBidiClass(wch)) {
case FX_BIDICLASS::kL:
direction = Direction::kLeft;
break;
case FX_BIDICLASS::kAN:
case FX_BIDICLASS::kEN:
case FX_BIDICLASS::kNSM:
case FX_BIDICLASS::kCS:
case FX_BIDICLASS::kES:
case FX_BIDICLASS::kET:
case FX_BIDICLASS::kBN:
direction = Direction::kLeftWeak;
break;
case FX_BIDICLASS::kR:
case FX_BIDICLASS::kAL:
direction = Direction::kRight;
break;
default:
direction = Direction::kNeutral;
break;
}
bool bChangeDirection = (direction != m_CurrentSegment.direction);
if (bChangeDirection)
StartNewSegment(direction);
m_CurrentSegment.count++;
return bChangeDirection;
}
bool CFX_BidiChar::EndChar() {
StartNewSegment(Direction::kNeutral);
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::Direction::kRight;
});
size_t nL2R = std::count_if(
m_Order.begin(), m_Order.end(), [](const CFX_BidiChar::Segment& seg) {
return seg.direction == CFX_BidiChar::Direction::kLeft;
});
if (nR2L > 0 && nR2L >= nL2R)
SetOverallDirectionRight();
}
CFX_BidiString::~CFX_BidiString() = default;
CFX_BidiChar::Direction CFX_BidiString::OverallDirection() const {
DCHECK_NE(m_eOverallDirection, CFX_BidiChar::Direction::kNeutral);
DCHECK_NE(m_eOverallDirection, CFX_BidiChar::Direction::kLeftWeak);
return m_eOverallDirection;
}
void CFX_BidiString::SetOverallDirectionRight() {
if (m_eOverallDirection != CFX_BidiChar::Direction::kRight) {
std::reverse(m_Order.begin(), m_Order.end());
m_eOverallDirection = CFX_BidiChar::Direction::kRight;
}
}