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      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 // }
     34 class 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