chromium/src/third_party/blink/renderer/platform/wtf/text/text_position.cc

/*
 * Copyright (C) 2013, Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

#include "third_party/blink/renderer/platform/wtf/text/text_position.h"

#include <algorithm>
#include <memory>
#include "third_party/blink/renderer/platform/wtf/std_lib_extras.h"

namespace WTF {

std::unique_ptr<Vector<wtf_size_t>> GetLineEndings(const String& text) {
  std::unique_ptr<Vector<wtf_size_t>> result(
      std::make_unique<Vector<wtf_size_t>>());

  unsigned start = 0;
  while (start < text.length()) {
    wtf_size_t line_end = text.find('\n', start);
    if (line_end == kNotFound)
      break;

    result->push_back(line_end);
    start = line_end + 1;
  }
  result->push_back(text.length());

  return result;
}

OrdinalNumber TextPosition::ToOffset(const Vector<unsigned>& line_endings) {
  unsigned line_start_offset =
      line_ != OrdinalNumber::First()
          ? line_endings.at(line_.ZeroBasedInt() - 1) + 1
          : 0;
  return OrdinalNumber::FromZeroBasedInt(line_start_offset +
                                         column_.ZeroBasedInt());
}

TextPosition TextPosition::FromOffsetAndLineEndings(
    unsigned offset,
    const Vector<unsigned>& line_endings) {
  const unsigned* found_line_ending =
      std::lower_bound(line_endings.begin(), line_endings.end(), offset);
  int line_index = static_cast<int>(found_line_ending - &line_endings.at(0));
  unsigned line_start_offset =
      line_index > 0 ? line_endings.at(line_index - 1) + 1 : 0;
  int column = offset - line_start_offset;
  return TextPosition(OrdinalNumber::FromZeroBasedInt(line_index),
                      OrdinalNumber::FromZeroBasedInt(column));
}

}  // namespace WTF