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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.
#include <string>
#include <vector>
#include "base/base_export.h"
#include "base/strings/string16.h"
#include "base/strings/string_piece.h"
namespace base {
// Like the conversions in utf_string_conversions.h, but also takes one or more
// |offset[s]_for_adjustment| representing insertion/selection points between
// characters: if |src| is "abcd", then 0 is before 'a', 2 is between 'b' and
// 'c', and 4 is at the end of the string. Valid input offsets range from 0 to
// |src_len|. On exit, each offset will have been modified to point at the same
// logical position in the output string. If an offset cannot be successfully
// adjusted (e.g. because it points into the middle of a multibyte sequence), it
// will be set to string16::npos.
// |offset[s]_for_adjustment| may be NULL.
BASE_EXPORT bool UTF8ToUTF16AndAdjustOffset(const char* src,
size_t src_len,
string16* output,
size_t* offset_for_adjustment);
BASE_EXPORT bool UTF8ToUTF16AndAdjustOffsets(
const char* src,
size_t src_len,
string16* output,
std::vector<size_t>* offsets_for_adjustment);
BASE_EXPORT string16 UTF8ToUTF16AndAdjustOffset(const base::StringPiece& utf8,
size_t* offset_for_adjustment);
BASE_EXPORT string16 UTF8ToUTF16AndAdjustOffsets(
const base::StringPiece& utf8,
std::vector<size_t>* offsets_for_adjustment);
BASE_EXPORT std::string UTF16ToUTF8AndAdjustOffset(
const base::StringPiece16& utf16,
size_t* offset_for_adjustment);
BASE_EXPORT std::string UTF16ToUTF8AndAdjustOffsets(
const base::StringPiece16& utf16,
std::vector<size_t>* offsets_for_adjustment);
// Limiting function callable by std::for_each which will replace any value
// which is greater than |limit| with npos. Typically this is called with a
// string length to clamp offsets into the string to [0, length] (as opposed to
// [0, length); see comments above).
template <typename T>
struct LimitOffset {
explicit LimitOffset(size_t limit)
: limit_(limit) {}
void operator()(size_t& offset) {
if (offset > limit_)
offset = T::npos;
size_t limit_;
// Stack object which, on destruction, will update a vector of offsets based on
// any supplied adjustments. To use, declare one of these, providing the
// address of the offset vector to adjust. Then Add() any number of Adjustments
// (each Adjustment gives the |original_offset| of a substring and the lengths
// of the substring before and after transforming). When the OffsetAdjuster
// goes out of scope, all the offsets in the provided vector will be updated.
class BASE_EXPORT OffsetAdjuster {
struct BASE_EXPORT Adjustment {
Adjustment(size_t original_offset,
size_t original_length,
size_t output_length);
size_t original_offset;
size_t original_length;
size_t output_length;
explicit OffsetAdjuster(std::vector<size_t>* offsets_for_adjustment);
void Add(const Adjustment& adjustment);
void AdjustOffset(std::vector<size_t>::iterator offset);
std::vector<size_t>* offsets_for_adjustment_;
std::vector<Adjustment> adjustments_;
} // namespace base