ScreenContext is moved to components/login.

chrome/browser/chromeos/login/screens/screen_context.h

-// 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 CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_SCREEN_CONTEXT_H_
-#define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_SCREEN_CONTEXT_H_
-
-#include <string>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/containers/hash_tables.h"
-#include "base/logging.h"
-#include "base/memory/linked_ptr.h"
-#include "base/strings/string16.h"
-#include "base/threading/non_thread_safe.h"
-#include "base/values.h"
-#include "chrome/browser/ui/webui/chromeos/login/base_screen_handler_utils.h"
-
-namespace chromeos {
-
-// 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 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;
-
-  // 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 chromeos
-
-#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_SCREEN_CONTEXT_H_