1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "text/Utf8Iterator.h"
18
19 #include "android-base/logging.h"
20 #include "utils/Unicode.h"
21
22 using ::android::StringPiece;
23
24 namespace aapt {
25 namespace text {
26
Utf8Iterator(const StringPiece & str)27 Utf8Iterator::Utf8Iterator(const StringPiece& str)
28 : str_(str), current_pos_(0), next_pos_(0), current_codepoint_(0) {
29 DoNext();
30 }
31
DoNext()32 void Utf8Iterator::DoNext() {
33 current_pos_ = next_pos_;
34 int32_t result = utf32_from_utf8_at(str_.data(), str_.size(), current_pos_, &next_pos_);
35 if (result == -1) {
36 current_codepoint_ = 0u;
37 } else {
38 current_codepoint_ = static_cast<char32_t>(result);
39 }
40 }
41
HasNext() const42 bool Utf8Iterator::HasNext() const {
43 return current_codepoint_ != 0;
44 }
45
Position() const46 size_t Utf8Iterator::Position() const {
47 return current_pos_;
48 }
49
Skip(int amount)50 void Utf8Iterator::Skip(int amount) {
51 while (amount > 0 && HasNext()) {
52 Next();
53 --amount;
54 }
55 }
56
Next()57 char32_t Utf8Iterator::Next() {
58 CHECK(HasNext()) << "Next() called after iterator exhausted";
59 char32_t result = current_codepoint_;
60 DoNext();
61 return result;
62 }
63
64 } // namespace text
65 } // namespace aapt
66