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.
5 #ifndef BASE_I18N_BIDI_LINE_ITERATOR_H_
6 #define BASE_I18N_BIDI_LINE_ITERATOR_H_
8 #include "base/i18n/base_i18n_export.h"
9 #include "base/i18n/rtl.h"
10 #include "base/macros.h"
11 #include "base/strings/string16.h"
12 #include "third_party/icu/source/common/unicode/ubidi.h"
13 #include "third_party/icu/source/common/unicode/uchar.h"
18 // A simple wrapper class for the bidirectional iterator of ICU.
19 // This class uses the bidirectional iterator of ICU to split a line of
20 // bidirectional texts into visual runs in its display order.
21 class BASE_I18N_EXPORT BiDiLineIterator {
23 // Specifies some alternative iteration behavior.
24 enum class CustomBehavior {
25 // No special behavior.
27 // Treat URL delimiter characters as strong LTR. This is a special treatment
28 // for URLs that purposefully violates the URL Standard, as an experiment.
29 // It should only be used behind a flag.
36 // Initializes the bidirectional iterator with the specified text. Returns
37 // whether initialization succeeded.
38 bool Open(const string16& text,
39 TextDirection direction,
40 CustomBehavior behavior);
42 // Returns the number of visual runs in the text, or zero on error.
43 int CountRuns() const;
45 // Gets the logical offset, length, and direction of the specified visual run.
46 UBiDiDirection GetVisualRun(int index, int* start, int* length) const;
48 // Given a start position, figure out where the run ends (and the BiDiLevel).
49 void GetLogicalRun(int start, int* end, UBiDiLevel* level) const;
54 DISALLOW_COPY_AND_ASSIGN(BiDiLineIterator);
60 #endif // BASE_I18N_BIDI_LINE_ITERATOR_H_