| // Copyright (c) 2013 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 COMPONENTS_LOGIN_SCREENS_SCREEN_CONTEXT_H_ |
| #define COMPONENTS_LOGIN_SCREENS_SCREEN_CONTEXT_H_ |
| |
| #include <string> |
| #include <vector> |
| |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/strings/string16.h" |
| #include "base/threading/non_thread_safe.h" |
| #include "base/values.h" |
| #include "components/login/base_screen_handler_utils.h" |
| #include "components/login/login_export.h" |
| |
| namespace login { |
| |
| // ScreenContext is a key-value storage for values that are shared |
| // between C++ and JS sides. Objects of this class should be used in |
| // the following way: |
| // |
| // context.SetString("user", "john"); |
| // context.SetInteger("image-index", 0); |
| // context.SetDouble("zoom", 1.25); |
| // context.GetChangesAndReset(&dictionary); |
| // CallJS("onContextChanged", dictionary); |
| // |
| // ScreenContext memorizes changed key-value pairs and returns them |
| // via GetChangesAndReset() method. After call to this method an |
| // internal buffer of changes will be cleared. |
| class LOGIN_EXPORT ScreenContext : public base::NonThreadSafe { |
| public: |
| typedef std::string KeyType; |
| typedef base::Value ValueType; |
| |
| ScreenContext(); |
| ~ScreenContext(); |
| |
| bool SetBoolean(const KeyType& key, bool value); |
| bool SetInteger(const KeyType& key, int value); |
| bool SetDouble(const KeyType& key, double value); |
| bool SetString(const KeyType& key, const std::string& value); |
| bool SetString(const KeyType& key, const base::string16& value); |
| bool SetStringList(const KeyType& key, const StringList& value); |
| bool SetString16List(const KeyType& key, const String16List& value); |
| |
| bool GetBoolean(const KeyType& key) const; |
| bool GetBoolean(const KeyType& key, bool default_value) const; |
| int GetInteger(const KeyType& key) const; |
| int GetInteger(const KeyType& key, int default_value) const; |
| double GetDouble(const KeyType& key) const; |
| double GetDouble(const KeyType& key, double default_value) const; |
| std::string GetString(const KeyType& key) const; |
| std::string GetString(const KeyType& key, |
| const std::string& default_value) const; |
| base::string16 GetString16(const KeyType& key) const; |
| base::string16 GetString16(const KeyType& key, |
| const base::string16& default_value) const; |
| StringList GetStringList(const KeyType& key) const; |
| StringList GetStringList(const KeyType& key, |
| const StringList& default_value) const; |
| String16List GetString16List(const KeyType& key) const; |
| String16List GetString16List(const KeyType& key, |
| const String16List& default_value) const; |
| |
| // Copies internal state of |context|. |
| void CopyFrom(ScreenContext& context); |
| |
| // Returns true if context has |key|. |
| bool HasKey(const KeyType& key) const; |
| |
| // Returns true if there was changes since last call to |
| // GetChangesAndReset(). |
| bool HasChanges() const; |
| |
| // Stores all changes since the last call to the |
| // GetChangesAndReset() in |diff|. All previous contents of |diff| |
| // will be thrown away. |
| void GetChangesAndReset(base::DictionaryValue* diff); |
| |
| // Applies changes from |diff| to the context. All keys from |diff| |
| // are stored in |keys|. |keys| argument is optional and can be NULL. |
| void ApplyChanges(const base::DictionaryValue& diff, |
| std::vector<std::string>* keys); |
| |
| // Returns underlying dictionary containing all the stored data. |
| const base::DictionaryValue& storage() const { return storage_; } |
| |
| private: |
| bool Set(const KeyType& key, base::Value* value); |
| |
| template <typename T> |
| T Get(const KeyType& key) const { |
| DCHECK(CalledOnValidThread()); |
| const base::Value* value; |
| bool has_key = storage_.Get(key, &value); |
| DCHECK(has_key); |
| T result; |
| if (!ParseValue(value, &result)) { |
| NOTREACHED(); |
| return T(); |
| } |
| return result; |
| } |
| |
| template <typename T> |
| T Get(const KeyType& key, const T& default_value) const { |
| DCHECK(CalledOnValidThread()); |
| if (!HasKey(key)) |
| return default_value; |
| return Get<T>(key); |
| } |
| |
| // Contains current state of <key, value> map. |
| base::DictionaryValue storage_; |
| |
| // Contains all pending changes. |
| base::DictionaryValue changes_; |
| |
| DISALLOW_COPY_AND_ASSIGN(ScreenContext); |
| }; |
| |
| } // namespace login |
| |
| #endif // COMPONENTS_LOGIN_SCREENS_SCREEN_CONTEXT_H_ |