base/i18n/bidi_line_iterator.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/i18n/bidi_line_iterator.h"
   6
   7 #include "base/logging.h"
   8
   9 namespace base {
  10 namespace i18n {
  11
  12 namespace {
  13   UBiDiLevel GetParagraphLevelForDirection(TextDirection direction) {
  14     switch (direction) {
  15       case UNKNOWN_DIRECTION:
  16         return UBIDI_DEFAULT_LTR;
  17         break;
  18       case RIGHT_TO_LEFT:
  19         return 1;  // Highest RTL level.
  20         break;
  21       case LEFT_TO_RIGHT:
  22         return 0;  // Highest LTR level.
  23         break;
  24       default:
  25         NOTREACHED();
  26         return 0;
  27     }
  28   }
  29 }  // namespace
  30
  31 BiDiLineIterator::BiDiLineIterator() : bidi_(NULL) {
  32 }
  33
  34 BiDiLineIterator::~BiDiLineIterator() {
  35   if (bidi_) {
  36     ubidi_close(bidi_);
  37     bidi_ = NULL;
  38   }
  39 }
  40
  41 bool BiDiLineIterator::Open(const string16& text, TextDirection direction) {
  42   DCHECK(!bidi_);
  43   UErrorCode error = U_ZERO_ERROR;
  44   bidi_ = ubidi_openSized(static_cast<int>(text.length()), 0, &error);
  45   if (U_FAILURE(error))
  46     return false;
  47   ubidi_setPara(bidi_, text.data(), static_cast<int>(text.length()),
  48                 GetParagraphLevelForDirection(direction), NULL, &error);
  49   return (U_SUCCESS(error) == TRUE);
  50 }
  51
  52 int BiDiLineIterator::CountRuns() {
  53   DCHECK(bidi_ != NULL);
  54   UErrorCode error = U_ZERO_ERROR;
  55   const int runs = ubidi_countRuns(bidi_, &error);
  56   return U_SUCCESS(error) ? runs : 0;
  57 }
  58
  59 UBiDiDirection BiDiLineIterator::GetVisualRun(int index,
  60                                               int* start,
  61                                               int* length) {
  62   DCHECK(bidi_ != NULL);
  63   return ubidi_getVisualRun(bidi_, index, start, length);
  64 }
  65
  66 void BiDiLineIterator::GetLogicalRun(int start,
  67                                      int* end,
  68                                      UBiDiLevel* level) {
  69   DCHECK(bidi_ != NULL);
  70   ubidi_getLogicalRun(bidi_, start, end, level);
  71 }
  72
  73 }  // namespace i18n
  74 }  // namespace base