1 /* 2 * Copyright (c) 2023 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef IMF_SYSTEM_LANGUAGE_OBSERVER_H 17 #define IMF_SYSTEM_LANGUAGE_OBSERVER_H 18 19 #include <functional> 20 #include <utility> 21 22 namespace OHOS { 23 namespace MiscServices { 24 class SystemLanguageObserver { 25 public: 26 using ChangeHandler = std::function<void()>; 27 static SystemLanguageObserver &GetInstance(); 28 void Watch(ChangeHandler handler); 29 30 private: 31 static constexpr const char *SYSTEM_LANGUAGE_KEY = "persist.global.language"; 32 SystemLanguageObserver() = default; 33 static void OnChange(const char *key, const char *value, void *context); 34 static ChangeHandler handler_; 35 }; 36 } // namespace MiscServices 37 } // namespace OHOS 38 39 #endif // IMF_SYSTEM_LANGUAGE_OBSERVER_H 40