Move pref_{member,service} and important_file_writer from chrome/common

to chrome/browser.

This is a part of an effort to remove bad dependency of chrome/common
on chrome/browser.

TEST=unit_tests and ui_tests, just moving code
BUG=none
Review URL: http://codereview.chromium.org/621004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@39428 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 222 insertions, 0 deletions

diff --git a/chrome/browser/pref_service.h b/chrome/browser/pref_service.h
new file mode 100644
index 0000000..85dd42c
--- /dev/null
+++ b/chrome/browser/pref_service.h
@@ -0,0 +1,222 @@
+// Copyright (c) 2006-2008 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.
+
+// This provides a way to access the application's current preferences.
+// This service has two preference stores, one for "persistent" preferences,
+// which get serialized for use in the next session, and one for "transient"
+// preferences, which are in effect for only the current session
+// (this usually encodes things like command-line switches).
+//
+// Calling the getter functions in this class basically looks at both the
+// persistent and transient stores, where any corresponding value in the
+// transient store overrides the one in the persistent store.
+
+#ifndef CHROME_BROWSER_PREF_SERVICE_H_
+#define CHROME_BROWSER_PREF_SERVICE_H_
+
+#include <set>
+
+#include "base/file_path.h"
+#include "base/hash_tables.h"
+#include "base/non_thread_safe.h"
+#include "base/observer_list.h"
+#include "base/scoped_ptr.h"
+#include "base/values.h"
+#include "chrome/browser/important_file_writer.h"
+
+class NotificationObserver;
+class Preference;
+
+class PrefService : public NonThreadSafe,
+                    public ImportantFileWriter::DataSerializer {
+ public:
+
+  // A helper class to store all the information associated with a preference.
+  class Preference {
+   public:
+
+    // The type of the preference is determined by the type of |default_value|.
+    // Therefore, the type needs to be a boolean, integer, real, string,
+    // dictionary (a branch), or list.  You shouldn't need to construct this on
+    // your own, use the PrefService::Register*Pref methods instead.
+    // |default_value| will be owned by the Preference object.
+    Preference(DictionaryValue* root_pref,
+               const wchar_t* name,
+               Value* default_value);
+    ~Preference() {}
+
+    Value::ValueType type() const { return type_; }
+
+    // Returns the name of the Preference (i.e., the key, e.g.,
+    // browser.window_placement).
+    const std::wstring name() const { return name_; }
+
+    // Returns the value of the Preference.  If there is no user specified
+    // value, it returns the default value.
+    const Value* GetValue() const;
+
+    // Returns true if the current value matches the default value.
+    bool IsDefaultValue() const;
+
+   private:
+    friend class PrefService;
+
+    Value::ValueType type_;
+    std::wstring name_;
+    scoped_ptr<Value> default_value_;
+
+    // A reference to the pref service's persistent prefs.
+    DictionaryValue* root_pref_;
+
+    DISALLOW_COPY_AND_ASSIGN(Preference);
+  };
+
+  // |pref_filename| is the path to the prefs file we will try to load or save
+  // to. Saves will be executed on the file thread.
+  explicit PrefService(const FilePath& pref_filename);
+  ~PrefService();
+
+  // Reloads the data from file. This should only be called when the importer
+  // is running during first run, and the main process may not change pref
+  // values while the importer process is running. Returns true on success.
+  bool ReloadPersistentPrefs();
+
+  // Writes the data to disk. The return value only reflects whether
+  // serialization was successful; we don't know whether the data actually made
+  // it on disk (since it's on a different thread).  This should only be used if
+  // we need to save immediately (basically, during shutdown).  Otherwise, you
+  // should use ScheduleSavePersistentPrefs.
+  bool SavePersistentPrefs();
+
+  // Serializes the data and schedules save using ImportantFileWriter.
+  void ScheduleSavePersistentPrefs();
+
+  // Make the PrefService aware of a pref.
+  void RegisterBooleanPref(const wchar_t* path,
+                           bool default_value);
+  void RegisterIntegerPref(const wchar_t* path,
+                           int default_value);
+  void RegisterRealPref(const wchar_t* path,
+                        double default_value);
+  void RegisterStringPref(const wchar_t* path,
+                          const std::wstring& default_value);
+  void RegisterFilePathPref(const wchar_t* path,
+                            const FilePath& default_value);
+  void RegisterListPref(const wchar_t* path);
+  void RegisterDictionaryPref(const wchar_t* path);
+
+  // These varients use a default value from the locale dll instead.
+  void RegisterLocalizedBooleanPref(const wchar_t* path,
+                                    int locale_default_message_id);
+  void RegisterLocalizedIntegerPref(const wchar_t* path,
+                                    int locale_default_message_id);
+  void RegisterLocalizedRealPref(const wchar_t* path,
+                                 int locale_default_message_id);
+  void RegisterLocalizedStringPref(const wchar_t* path,
+                                   int locale_default_message_id);
+
+  // If the path is valid and the value at the end of the path matches the type
+  // specified, it will return the specified value.  Otherwise, the default
+  // value (set when the pref was registered) will be returned.
+  bool GetBoolean(const wchar_t* path) const;
+  int GetInteger(const wchar_t* path) const;
+  double GetReal(const wchar_t* path) const;
+  std::wstring GetString(const wchar_t* path) const;
+  FilePath GetFilePath(const wchar_t* path) const;
+
+  // Returns the branch if it exists.  If it's not a branch or the branch does
+  // not exist, returns NULL.
+  const DictionaryValue* GetDictionary(const wchar_t* path) const;
+  const ListValue* GetList(const wchar_t* path) const;
+
+  // If the pref at the given path changes, we call the observer's Observe
+  // method with NOTIFY_PREF_CHANGED.
+  void AddPrefObserver(const wchar_t* path, NotificationObserver* obs);
+  void RemovePrefObserver(const wchar_t* path, NotificationObserver* obs);
+
+  // Removes a user pref and restores the pref to its default value.
+  void ClearPref(const wchar_t* path);
+
+  // If the path is valid (i.e., registered), update the pref value.
+  void Set(const wchar_t* path, const Value& value);
+  void SetBoolean(const wchar_t* path, bool value);
+  void SetInteger(const wchar_t* path, int value);
+  void SetReal(const wchar_t* path, double value);
+  void SetString(const wchar_t* path, const std::wstring& value);
+  void SetFilePath(const wchar_t* path, const FilePath& value);
+
+  // Int64 helper methods that actually store the given value as a string.
+  // Note that if obtaining the named value via GetDictionary or GetList, the
+  // Value type will be TYPE_STRING.
+  void SetInt64(const wchar_t* path, int64 value);
+  int64 GetInt64(const wchar_t* path) const;
+  void RegisterInt64Pref(const wchar_t* path, int64 default_value);
+
+  // Used to set the value of dictionary or list values in the pref tree.  This
+  // will create a dictionary or list if one does not exist in the pref tree.
+  // This method returns NULL only if you're requesting an unregistered pref or
+  // a non-dict/non-list pref.
+  // WARNING: Changes to the dictionary or list will not automatically notify
+  // pref observers. TODO(tc): come up with a way to still fire observers.
+  DictionaryValue* GetMutableDictionary(const wchar_t* path);
+  ListValue* GetMutableList(const wchar_t* path);
+
+  // Returns true if a value has been set for the specified path.
+  // NOTE: this is NOT the same as FindPreference. In particular
+  // FindPreference returns whether RegisterXXX has been invoked, where as
+  // this checks if a value exists for the path.
+  bool HasPrefPath(const wchar_t* path) const;
+
+  class PreferencePathComparator {
+   public:
+    bool operator() (Preference* lhs, Preference* rhs) const {
+      return lhs->name() < rhs->name();
+    }
+  };
+  typedef std::set<Preference*, PreferencePathComparator> PreferenceSet;
+  const PreferenceSet& preference_set() const { return prefs_; }
+
+  // A helper method to quickly look up a preference.  Returns NULL if the
+  // preference is not registered.
+  const Preference* FindPreference(const wchar_t* pref_name) const;
+
+  // ImportantFileWriter::DataSerializer
+  virtual bool SerializeData(std::string* output);
+
+ private:
+  // Add a preference to the PreferenceMap.  If the pref already exists, return
+  // false.  This method takes ownership of |pref|.
+  void RegisterPreference(Preference* pref);
+
+  // Returns a copy of the current pref value.  The caller is responsible for
+  // deleting the returned object.
+  Value* GetPrefCopy(const wchar_t* pref_name);
+
+  // For the given pref_name, fire any observer of the pref.
+  void FireObservers(const wchar_t* pref_name);
+
+  // For the given pref_name, fire any observer of the pref only if |old_value|
+  // is different from the current value.
+  void FireObserversIfChanged(const wchar_t* pref_name,
+                              const Value* old_value);
+
+  scoped_ptr<DictionaryValue> persistent_;
+
+  // Helper for safe writing pref data.
+  ImportantFileWriter writer_;
+
+  // A set of all the registered Preference objects.
+  PreferenceSet prefs_;
+
+  // A map from pref names to a list of observers.  Observers get fired in the
+  // order they are added.
+  typedef ObserverList<NotificationObserver> NotificationObserverList;
+  typedef base::hash_map<std::wstring, NotificationObserverList*>
+      PrefObserverMap;
+  PrefObserverMap pref_observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrefService);
+};
+
+#endif  // CHROME_BROWSER_PREF_SERVICE_H_