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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_I18N_BIDI_LINE_ITERATOR_H_
#define BASE_I18N_BIDI_LINE_ITERATOR_H_
#include "base/i18n/base_i18n_export.h"
#include "base/i18n/rtl.h"
#include "base/macros.h"
#include "base/strings/string16.h"
#include "third_party/icu/source/common/unicode/ubidi.h"
#include "third_party/icu/source/common/unicode/uchar.h"
namespace base {
namespace i18n {
// A simple wrapper class for the bidirectional iterator of ICU.
// This class uses the bidirectional iterator of ICU to split a line of
// bidirectional texts into visual runs in its display order.
class BASE_I18N_EXPORT BiDiLineIterator {
public:
// Specifies some alternative iteration behavior.
enum class CustomBehavior {
// No special behavior.
NONE,
// Treat URL delimiter characters as strong LTR. This is a special treatment
// for URLs that purposefully violates the URL Standard, as an experiment.
// It should only be used behind a flag.
AS_URL
};
BiDiLineIterator();
~BiDiLineIterator();
// Initializes the bidirectional iterator with the specified text. Returns
// whether initialization succeeded.
bool Open(const string16& text,
TextDirection direction,
CustomBehavior behavior);
// Returns the number of visual runs in the text, or zero on error.
int CountRuns() const;
// Gets the logical offset, length, and direction of the specified visual run.
UBiDiDirection GetVisualRun(int index, int* start, int* length) const;
// Given a start position, figure out where the run ends (and the BiDiLevel).
void GetLogicalRun(int start, int* end, UBiDiLevel* level) const;
private:
UBiDi* bidi_;
DISALLOW_COPY_AND_ASSIGN(BiDiLineIterator);
};
} // namespace i18n
} // namespace base
#endif // BASE_I18N_BIDI_LINE_ITERATOR_H_
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