/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsBidi.h"

nsresult

nsBidi::CountRuns(int32_t* aRunCount)

{

  UErrorCode errorCode = U_ZERO_ERROR;

  *aRunCount = ubidi_countRuns(mBiDi, &errorCode);

  if (U_SUCCESS(errorCode)) {

    mLength = ubidi_getProcessedLength(mBiDi);

    mLevels = mLength > 0 ? ubidi_getLevels(mBiDi, &errorCode) : nullptr;

  }

  return ICUUtils::UErrorToNsResult(errorCode);

}

void

nsBidi::GetLogicalRun(int32_t aLogicalStart,

                      int32_t* aLogicalLimit, nsBidiLevel* aLevel)

{

  MOZ_ASSERT(mLevels, "CountRuns hasn't been run?");

  MOZ_RELEASE_ASSERT(aLogicalStart < mLength, "Out of bound");

  // This function implements an alternative approach to get logical

  // run that is based on levels of characters, which would avoid O(n^2)

  // performance issue when used in a loop over runs.

  // Per comment in ubidi_getLogicalRun, that function doesn't use this

  // approach because levels have special interpretation when reordering

  // mode is UBIDI_REORDER_RUNS_ONLY. Since we don't use this mode in

  // Gecko, it should be safe to just use levels for this function.

  MOZ_ASSERT(ubidi_getReorderingMode(mBiDi) != UBIDI_REORDER_RUNS_ONLY,

             "Don't support UBIDI_REORDER_RUNS_ONLY mode");

  nsBidiLevel level = mLevels[aLogicalStart];

  int32_t limit;

  for (limit = aLogicalStart + 1; limit < mLength; limit++) {

    if (mLevels[limit] != level) {

      break;

    }

  }

  *aLogicalLimit = limit;

  *aLevel = level;

}