1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3  * License, v. 2.0. If a copy of the MPL was not distributed with this
4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 
6 #ifndef mozilla_TransactionStack_h
7 #define mozilla_TransactionStack_h
8 
9 #include "mozilla/AlreadyAddRefed.h"
10 #include "nsDeque.h"
11 
12 class nsCycleCollectionTraversalCallback;
13 
14 namespace mozilla {
15 
16 class TransactionItem;
17 
18 class TransactionStack : private nsRefPtrDeque<TransactionItem> {
19  public:
20   enum Type { FOR_UNDO, FOR_REDO };
21 
22   explicit TransactionStack(Type aType);
23   ~TransactionStack();
24 
25   void Push(TransactionItem* aTransactionItem);
26   void Push(already_AddRefed<TransactionItem> aTransactionItem);
27   already_AddRefed<TransactionItem> Pop();
28   already_AddRefed<TransactionItem> PopBottom();
29   already_AddRefed<TransactionItem> Peek() const;
30   already_AddRefed<TransactionItem> GetItemAt(size_t aIndex) const;
31   void Clear();
GetSize()32   size_t GetSize() const { return nsRefPtrDeque<TransactionItem>::GetSize(); }
IsEmpty()33   bool IsEmpty() const { return GetSize() == 0; }
34 
DoUnlink()35   void DoUnlink() { Clear(); }
36   void DoTraverse(nsCycleCollectionTraversalCallback& cb);
37 
38  private:
39   const Type mType;
40 };
41 
42 }  // namespace mozilla
43 
44 #endif  // mozilla_TransactionStack_h
45