1// Copyright 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// The classes in this file are alternative implementations of the concept of a
6// "prompt memento", a token of some kind that gets stored when we show the
7// one-time profile reset prompt, and which then serves as a reminder that we
8// should not show the prompt again.
9//
10// In an ideal world, a single implementation would suffice, however, we expect
11// that third party software might accidentally interfere with some of these
12// methods. We need this redundancy because we want to make absolutely sure that
13// we do not annoy the user with the prompt multiple times.
14
15#ifndef CHROME_BROWSER_PROFILE_RESETTER_AUTOMATIC_PROFILE_RESETTER_MEMENTOS_H_
16#define CHROME_BROWSER_PROFILE_RESETTER_AUTOMATIC_PROFILE_RESETTER_MEMENTOS_H_
17
18#include <string>
19
20#include "base/basictypes.h"
21#include "base/callback.h"
22
23namespace base {
24class FilePath;
25}
26
27class Profile;
28
29// This class is a wrapper around the user preference that gets stored when we
30// show the one-time profile reset prompt, and which is kept as a reminder that
31// we should not show the prompt again.
32class PreferenceHostedPromptMemento {
33 public:
34  explicit PreferenceHostedPromptMemento(Profile* profile);
35  ~PreferenceHostedPromptMemento();
36
37  std::string ReadValue() const;
38  void StoreValue(const std::string& value);
39
40 private:
41  Profile* profile_;
42
43  DISALLOW_COPY_AND_ASSIGN(PreferenceHostedPromptMemento);
44};
45
46// This class is a wrapper around the Local State preference that gets stored
47// when we show the one-time profile reset prompt, and which is kept as a
48// reminder that we should not show the prompt again.
49class LocalStateHostedPromptMemento {
50 public:
51  explicit LocalStateHostedPromptMemento(Profile* profile);
52  ~LocalStateHostedPromptMemento();
53
54  std::string ReadValue() const;
55  void StoreValue(const std::string& value);
56
57 private:
58  // Returns the key that shall be used in the dictionary preference in Local
59  // State to uniquely identify this profile.
60  std::string GetProfileKey() const;
61
62  Profile* profile_;
63
64  DISALLOW_COPY_AND_ASSIGN(LocalStateHostedPromptMemento);
65};
66
67// This class manages a marker file that gets stored when we show the one-time
68// profile reset prompt, and which is kept as a reminder that we should not show
69// the prompt again.
70class FileHostedPromptMemento {
71 public:
72  typedef base::Callback<void(const std::string&)> ReadValueCallback;
73
74  explicit FileHostedPromptMemento(Profile* profile);
75  ~FileHostedPromptMemento();
76
77  // Posts to the FILE thread to read the value, then returns the value to the
78  // calling thread. It is safe to destroy this object as soon as this method
79  // (synchronously) returns.
80  void ReadValue(const ReadValueCallback& callback) const;
81
82  // Asynchronously stores the value on the FILE thread. However, it is safe to
83  // destroy this object as soon as this method (synchronously) returns.
84  void StoreValue(const std::string& value);
85
86 private:
87  static std::string ReadValueOnFileThread(
88      const base::FilePath& memento_file_path);
89  static void StoreValueOnFileThread(const base::FilePath& memento_file_path,
90                                     const std::string& value);
91
92  // Returns the path to the file that shall be used to store this kind of
93  // memento for this profile.
94  base::FilePath GetMementoFilePath() const;
95
96  Profile* profile_;
97
98  DISALLOW_COPY_AND_ASSIGN(FileHostedPromptMemento);
99};
100
101#endif  // CHROME_BROWSER_PROFILE_RESETTER_AUTOMATIC_PROFILE_RESETTER_MEMENTOS_H_
102