editor/txmgr/nsTransactionStack.cpp

   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 #include "nsAutoPtr.h"
   7 #include "nsCOMPtr.h"
   8 #include "nsCycleCollectionParticipant.h"
   9 #include "nsISupportsUtils.h"
  10 #include "nsTransactionItem.h"
  11 #include "nsTransactionStack.h"
  12 #include "nscore.h"
  13
  14 nsTransactionStack::nsTransactionStack(nsTransactionStack::Type aType)
  15   : mType(aType)
  16 {
  17 }
  18
  19 nsTransactionStack::~nsTransactionStack()
  20 {
  21   Clear();
  22 }
  23
  24 void
  25 nsTransactionStack::Push(nsTransactionItem *aTransaction)
  26 {
  27   if (!aTransaction) {
  28     return;
  29   }
  30
  31   // The stack's bottom is the front of the deque, and the top is the back.
  32   mDeque.push_back(aTransaction);
  33 }
  34
  35 already_AddRefed<nsTransactionItem>
  36 nsTransactionStack::Pop()
  37 {
  38   if (mDeque.empty()) {
  39     return nullptr;
  40   }
  41   nsRefPtr<nsTransactionItem> ret = mDeque.back().forget();
  42   mDeque.pop_back();
  43   return ret.forget();
  44 }
  45
  46 already_AddRefed<nsTransactionItem>
  47 nsTransactionStack::PopBottom()
  48 {
  49   if (mDeque.empty()) {
  50     return nullptr;
  51   }
  52   nsRefPtr<nsTransactionItem> ret = mDeque.front().forget();
  53   mDeque.pop_front();
  54   return ret.forget();
  55 }
  56
  57 already_AddRefed<nsTransactionItem>
  58 nsTransactionStack::Peek()
  59 {
  60   if (mDeque.empty()) {
  61     return nullptr;
  62   }
  63   nsRefPtr<nsTransactionItem> ret = mDeque.back();
  64   return ret.forget();
  65 }
  66
  67 already_AddRefed<nsTransactionItem>
  68 nsTransactionStack::GetItem(int32_t aIndex)
  69 {
  70   if (aIndex < 0 || aIndex >= static_cast<int32_t>(mDeque.size())) {
  71     return nullptr;
  72   }
  73   nsRefPtr<nsTransactionItem> ret = mDeque[aIndex];
  74   return ret.forget();
  75 }
  76
  77 void
  78 nsTransactionStack::Clear()
  79 {
  80   while (!mDeque.empty()) {
  81     nsRefPtr<nsTransactionItem> tx = mType == FOR_UNDO ? Pop() : PopBottom();
  82   };
  83 }
  84
  85 void
  86 nsTransactionStack::DoTraverse(nsCycleCollectionTraversalCallback &cb)
  87 {
  88   int32_t size = mDeque.size();
  89   for (int32_t i = 0; i < size; ++i) {
  90     nsTransactionItem* item = mDeque[i];
  91     if (item) {
  92       NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "transaction stack mDeque[i]");
  93       cb.NoteNativeChild(item, NS_CYCLE_COLLECTION_PARTICIPANT(nsTransactionItem));
  94     }
  95   }
  96 }