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_INSTALLER_UTIL_CALLBACK_WORK_ITEM_H_
6#define CHROME_INSTALLER_UTIL_CALLBACK_WORK_ITEM_H_
7
8#include "base/callback.h"
9#include "base/compiler_specific.h"
10#include "base/gtest_prod_util.h"
11#include "chrome/installer/util/work_item.h"
12
13// A work item that invokes a callback on Do() and Rollback().  In the following
14// example, the function SomeWorkItemCallback() will be invoked when an item
15// list is processed.
16//
17// // A callback invoked to do some work.
18// bool SomeWorkItemCallback(const CallbackWorkItem& item) {
19//   if (item.IsRollback()) {
20//     // Rollback work goes here.  The return value is ignored in this case.
21//     return true;
22//   }
23//
24//   // Roll forward work goes here.  The return value indicates success/failure
25//   // of the item.
26//   return true;
27// }
28//
29// void SomeFunctionThatAddsItemsToAList(WorkItemList* item_list) {
30//   ...
31//   item_list->AddCallbackWorkItem(base::Bind(&SomeWorkItemCallback));
32//   ...
33// }
34class CallbackWorkItem : public WorkItem {
35 public:
36  virtual ~CallbackWorkItem();
37
38  virtual bool Do() OVERRIDE;
39  virtual void Rollback() OVERRIDE;
40
41  bool IsRollback() const;
42
43 private:
44  friend class WorkItem;
45
46  enum RollState {
47    RS_UNDEFINED,
48    RS_FORWARD,
49    RS_BACKWARD,
50  };
51
52  CallbackWorkItem(base::Callback<bool(const CallbackWorkItem&)> callback);
53
54  base::Callback<bool(const CallbackWorkItem&)> callback_;
55  RollState roll_state_;
56
57  FRIEND_TEST_ALL_PREFIXES(CallbackWorkItemTest, TestFailure);
58  FRIEND_TEST_ALL_PREFIXES(CallbackWorkItemTest, TestForwardBackward);
59};
60
61#endif  // CHROME_INSTALLER_UTIL_CALLBACK_WORK_ITEM_H_
62