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
8#include "base/basictypes.h"
9#include "base/i18n/base_i18n_export.h"
10#include "base/strings/string16.h"
11#include "third_party/icu/source/common/unicode/ubidi.h"
12
13namespace base {
14namespace i18n {
15
16// A simple wrapper class for the bidirectional iterator of ICU.
17// This class uses the bidirectional iterator of ICU to split a line of
18// bidirectional texts into visual runs in its display order.
19class BASE_I18N_EXPORT BiDiLineIterator {
20 public:
21  BiDiLineIterator();
22  ~BiDiLineIterator();
23
24  // Initializes the bidirectional iterator with the specified text.  Returns
25  // whether initialization succeeded.
26  bool Open(const string16& text, bool right_to_left, bool url);
27
28  // Returns the number of visual runs in the text, or zero on error.
29  int CountRuns();
30
31  // Gets the logical offset, length, and direction of the specified visual run.
32  UBiDiDirection GetVisualRun(int index, int* start, int* length);
33
34  // Given a start position, figure out where the run ends (and the BiDiLevel).
35  void GetLogicalRun(int start, int* end, UBiDiLevel* level);
36
37 private:
38  UBiDi* bidi_;
39
40  DISALLOW_COPY_AND_ASSIGN(BiDiLineIterator);
41};
42
43}  // namespace i18n
44}  // namespace base
45
46#endif  // BASE_I18N_BIDI_LINE_ITERATOR_H_
47