chrome/browser/value_store/value_store_change.h

   1 // Copyright (c) 2012 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 #ifndef CHROME_BROWSER_VALUE_STORE_VALUE_STORE_CHANGE_H_
   6 #define CHROME_BROWSER_VALUE_STORE_VALUE_STORE_CHANGE_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/values.h"
  14
  15 class ValueStoreChange;
  16 typedef std::vector<ValueStoreChange> ValueStoreChangeList;
  17
  18 // A change to a setting.  Safe/efficient to copy.
  19 class ValueStoreChange {
  20  public:
  21   // Converts an ValueStoreChangeList into JSON of the form:
  22   // { "foo": { "key": "foo", "oldValue": "bar", "newValue": "baz" } }
  23   static std::string ToJson(const ValueStoreChangeList& changes);
  24
  25   // Ownership of |old_value| and |new_value| taken.
  26   ValueStoreChange(
  27       const std::string& key, base::Value* old_value, base::Value* new_value);
  28
  29   ~ValueStoreChange();
  30
  31   // Gets the key of the setting which changed.
  32   const std::string& key() const;
  33
  34   // Gets the value of the setting before the change, or NULL if there was no
  35   // old value.
  36   const base::Value* old_value() const;
  37
  38   // Gets the value of the setting after the change, or NULL if there is no new
  39   // value.
  40   const base::Value* new_value() const;
  41
  42  private:
  43   class Inner : public base::RefCountedThreadSafe<Inner> {
  44    public:
  45     Inner(
  46         const std::string& key, base::Value* old_value, base::Value* new_value);
  47
  48     const std::string key_;
  49     const scoped_ptr<base::Value> old_value_;
  50     const scoped_ptr<base::Value> new_value_;
  51
  52    private:
  53     friend class base::RefCountedThreadSafe<Inner>;
  54     virtual ~Inner();
  55   };
  56
  57   scoped_refptr<Inner> inner_;
  58 };
  59
  60 #endif  // CHROME_BROWSER_VALUE_STORE_VALUE_STORE_CHANGE_H_