1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "nsBidi.h"
8
CountRuns(int32_t * aRunCount)9 nsresult nsBidi::CountRuns(int32_t* aRunCount) {
10 UErrorCode errorCode = U_ZERO_ERROR;
11 *aRunCount = ubidi_countRuns(mBiDi, &errorCode);
12 if (U_SUCCESS(errorCode)) {
13 mLength = ubidi_getProcessedLength(mBiDi);
14 mLevels = mLength > 0 ? ubidi_getLevels(mBiDi, &errorCode) : nullptr;
15 }
16 return ICUUtils::UErrorToNsResult(errorCode);
17 }
18
GetLogicalRun(int32_t aLogicalStart,int32_t * aLogicalLimit,nsBidiLevel * aLevel)19 void nsBidi::GetLogicalRun(int32_t aLogicalStart, int32_t* aLogicalLimit,
20 nsBidiLevel* aLevel) {
21 MOZ_ASSERT(mLevels, "CountRuns hasn't been run?");
22 MOZ_RELEASE_ASSERT(aLogicalStart < mLength, "Out of bound");
23 // This function implements an alternative approach to get logical
24 // run that is based on levels of characters, which would avoid O(n^2)
25 // performance issue when used in a loop over runs.
26 // Per comment in ubidi_getLogicalRun, that function doesn't use this
27 // approach because levels have special interpretation when reordering
28 // mode is UBIDI_REORDER_RUNS_ONLY. Since we don't use this mode in
29 // Gecko, it should be safe to just use levels for this function.
30 MOZ_ASSERT(ubidi_getReorderingMode(mBiDi) != UBIDI_REORDER_RUNS_ONLY,
31 "Don't support UBIDI_REORDER_RUNS_ONLY mode");
32
33 nsBidiLevel level = mLevels[aLogicalStart];
34 int32_t limit;
35 for (limit = aLogicalStart + 1; limit < mLength; limit++) {
36 if (mLevels[limit] != level) {
37 break;
38 }
39 }
40 *aLogicalLimit = limit;
41 *aLevel = level;
42 }
43