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      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 #ifndef BASE_I18N_BIDI_LINE_ITERATOR_H_
      6 #define BASE_I18N_BIDI_LINE_ITERATOR_H_
      7 #pragma once
      8 
      9 #include "unicode/ubidi.h"
     10 
     11 #include "base/basictypes.h"
     12 #include "base/string16.h"
     13 
     14 namespace base {
     15 namespace i18n {
     16 
     17 // A simple wrapper class for the bidirectional iterator of ICU.
     18 // This class uses the bidirectional iterator of ICU to split a line of
     19 // bidirectional texts into visual runs in its display order.
     20 class BiDiLineIterator {
     21  public:
     22   BiDiLineIterator();
     23   ~BiDiLineIterator();
     24 
     25   // Initializes the bidirectional iterator with the specified text.  Returns
     26   // whether initialization succeeded.
     27   bool Open(const string16& text, bool right_to_left, bool url);
     28 
     29   // Returns the number of visual runs in the text, or zero on error.
     30   int CountRuns();
     31 
     32   // Gets the logical offset, length, and direction of the specified visual run.
     33   UBiDiDirection GetVisualRun(int index, int* start, int* length);
     34 
     35   // Given a start position, figure out where the run ends (and the BiDiLevel).
     36   void GetLogicalRun(int start, int* end, UBiDiLevel* level);
     37 
     38  private:
     39   UBiDi* bidi_;
     40 
     41   DISALLOW_COPY_AND_ASSIGN(BiDiLineIterator);
     42 };
     43 
     44 }  // namespace i18n
     45 }  // namespace base
     46 
     47 #endif  // BASE_I18N_BIDI_LINE_ITERATOR_H_
     48