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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #include "mozilla/mozalloc.h"

 #include "nsAutoPtr.h"

 #include "nsCOMPtr.h"

 #include "nsDebug.h"

 #include "nsError.h"

 #include "nsISupportsImpl.h"

 #include "nsITransaction.h"

 #include "nsTransactionItem.h"

 #include "nsTransactionManager.h"

 #include "nsTransactionStack.h"

 nsTransactionItem::nsTransactionItem(nsITransaction *aTransaction)

     : mTransaction(aTransaction), mUndoStack(0), mRedoStack(0)

 {

 }

 nsTransactionItem::~nsTransactionItem()

 {

   delete mRedoStack;

   delete mUndoStack;

 }

 void

 nsTransactionItem::CleanUp()

 {

   mData.Clear();

   mTransaction = nullptr;

   if (mRedoStack) {

     mRedoStack->DoUnlink();

   }

   if (mUndoStack) {

     mUndoStack->DoUnlink();

   }

 }

 NS_IMPL_CYCLE_COLLECTING_NATIVE_ADDREF(nsTransactionItem)

 NS_IMPL_CYCLE_COLLECTING_NATIVE_RELEASE_WITH_LAST_RELEASE(nsTransactionItem,

                                                           CleanUp())

 NS_IMPL_CYCLE_COLLECTION_CLASS(nsTransactionItem)

 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsTransactionItem)

   tmp->CleanUp();

 NS_IMPL_CYCLE_COLLECTION_UNLINK_END

 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsTransactionItem)

   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mData)

   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTransaction)

   if (tmp->mRedoStack) {

     tmp->mRedoStack->DoTraverse(cb);

   }

   if (tmp->mUndoStack) {

     tmp->mUndoStack->DoTraverse(cb);

   }

 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(nsTransactionItem, AddRef)

 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(nsTransactionItem, Release)

 nsresult

 nsTransactionItem::AddChild(nsTransactionItem *aTransactionItem)

 {

   NS_ENSURE_TRUE(aTransactionItem, NS_ERROR_NULL_POINTER);

   if (!mUndoStack) {

     mUndoStack = new nsTransactionStack(nsTransactionStack::FOR_UNDO);

   }

   mUndoStack->Push(aTransactionItem);

   return NS_OK;

 }

 already_AddRefed<nsITransaction>

 nsTransactionItem::GetTransaction()

 {

   nsCOMPtr<nsITransaction> txn = mTransaction;

   return txn.forget();

 }

 nsresult

 nsTransactionItem::GetIsBatch(bool *aIsBatch)

 {

   NS_ENSURE_TRUE(aIsBatch, NS_ERROR_NULL_POINTER);

   *aIsBatch = !mTransaction;

   return NS_OK;

 }

 nsresult

 nsTransactionItem::GetNumberOfChildren(int32_t *aNumChildren)

 {

   nsresult result;

   NS_ENSURE_TRUE(aNumChildren, NS_ERROR_NULL_POINTER);

   *aNumChildren = 0;

   int32_t ui = 0;

   int32_t ri = 0;

   result = GetNumberOfUndoItems(&ui);

   NS_ENSURE_SUCCESS(result, result);

   result = GetNumberOfRedoItems(&ri);

   NS_ENSURE_SUCCESS(result, result);

   *aNumChildren = ui + ri;

   return NS_OK;

 }

 nsresult

 nsTransactionItem::GetChild(int32_t aIndex, nsTransactionItem **aChild)

 {

   NS_ENSURE_TRUE(aChild, NS_ERROR_NULL_POINTER);

   *aChild = 0;

   int32_t numItems = 0;

   nsresult result = GetNumberOfChildren(&numItems);

   NS_ENSURE_SUCCESS(result, result);

   if (aIndex < 0 || aIndex >= numItems)

     return NS_ERROR_FAILURE;

   // Children are expected to be in the order they were added,

   // so the child first added would be at the bottom of the undo

   // stack, or if there are no items on the undo stack, it would

   // be at the top of the redo stack.

   result = GetNumberOfUndoItems(&numItems);

   NS_ENSURE_SUCCESS(result, result);

   if (numItems > 0 && aIndex < numItems) {

     NS_ENSURE_TRUE(mUndoStack, NS_ERROR_FAILURE);

     nsRefPtr<nsTransactionItem> child = mUndoStack->GetItem(aIndex);

     child.forget(aChild);

     return *aChild ? NS_OK : NS_ERROR_FAILURE;

   }

   // Adjust the index for the redo stack:

   aIndex -=  numItems;

   result = GetNumberOfRedoItems(&numItems);

   NS_ENSURE_SUCCESS(result, result);

   NS_ENSURE_TRUE(mRedoStack && numItems != 0 && aIndex < numItems, NS_ERROR_FAILURE);

   nsRefPtr<nsTransactionItem> child = mRedoStack->GetItem(aIndex);

   child.forget(aChild);

   return *aChild ? NS_OK : NS_ERROR_FAILURE;

 }

 nsresult

 nsTransactionItem::DoTransaction()

 {

   if (mTransaction)

     return mTransaction->DoTransaction();

   return NS_OK;

 }

 nsresult

 nsTransactionItem::UndoTransaction(nsTransactionManager *aTxMgr)

 {

   nsresult result = UndoChildren(aTxMgr);

   if (NS_FAILED(result)) {

     RecoverFromUndoError(aTxMgr);

     return result;

   }

   if (!mTransaction)

     return NS_OK;

   result = mTransaction->UndoTransaction();

   if (NS_FAILED(result)) {

     RecoverFromUndoError(aTxMgr);

     return result;

   }

   return NS_OK;

 }

 nsresult

 nsTransactionItem::UndoChildren(nsTransactionManager *aTxMgr)

 {

   nsRefPtr<nsTransactionItem> item;

   nsresult result = NS_OK;

   int32_t sz = 0;

   if (mUndoStack) {

     if (!mRedoStack && mUndoStack) {

       mRedoStack = new nsTransactionStack(nsTransactionStack::FOR_REDO);

     }

     /* Undo all of the transaction items children! */

     sz = mUndoStack->GetSize();

     while (sz-- > 0) {

       item = mUndoStack->Peek();

       if (!item) {

         return NS_ERROR_FAILURE;

       }

       nsCOMPtr<nsITransaction> t = item->GetTransaction();

       bool doInterrupt = false;

       result = aTxMgr->WillUndoNotify(t, &doInterrupt);

       if (NS_FAILED(result)) {

         return result;

       }

       if (doInterrupt) {

         return NS_OK;

       }

       result = item->UndoTransaction(aTxMgr);

       if (NS_SUCCEEDED(result)) {

         item = mUndoStack->Pop();

         mRedoStack->Push(item);

       }

       nsresult result2 = aTxMgr->DidUndoNotify(t, result);

       if (NS_SUCCEEDED(result)) {

         result = result2;

       }

     }

   }

   return result;

 }

 nsresult

 nsTransactionItem::RedoTransaction(nsTransactionManager *aTxMgr)

 {

   nsresult result;

   nsCOMPtr<nsITransaction> kungfuDeathGrip(mTransaction);

   if (mTransaction) {

     result = mTransaction->RedoTransaction();

     NS_ENSURE_SUCCESS(result, result);

   }

   result = RedoChildren(aTxMgr);

   if (NS_FAILED(result)) {

     RecoverFromRedoError(aTxMgr);

     return result;

   }

   return NS_OK;

 }

 nsresult

 nsTransactionItem::RedoChildren(nsTransactionManager *aTxMgr)

 {

   nsRefPtr<nsTransactionItem> item;

   nsresult result = NS_OK;

   if (!mRedoStack)

     return NS_OK;

   /* Redo all of the transaction items children! */

   int32_t sz = mRedoStack->GetSize();

   while (sz-- > 0) {

     item = mRedoStack->Peek();

     if (!item) {

       return NS_ERROR_FAILURE;

     }

     nsCOMPtr<nsITransaction> t = item->GetTransaction();

     bool doInterrupt = false;

     result = aTxMgr->WillRedoNotify(t, &doInterrupt);

     if (NS_FAILED(result)) {

       return result;

     }

     if (doInterrupt) {

       return NS_OK;

     }

     result = item->RedoTransaction(aTxMgr);

     if (NS_SUCCEEDED(result)) {

       item = mRedoStack->Pop();

       mUndoStack->Push(item);

     }

     nsresult result2 = aTxMgr->DidUndoNotify(t, result);

     if (NS_SUCCEEDED(result)) {

       result = result2;

     }

   }

   return result;

 }

 nsresult

 nsTransactionItem::GetNumberOfUndoItems(int32_t *aNumItems)

 {

   NS_ENSURE_TRUE(aNumItems, NS_ERROR_NULL_POINTER);

   if (!mUndoStack) {

     *aNumItems = 0;

     return NS_OK;

   }

   *aNumItems = mUndoStack->GetSize();

   return *aNumItems ? NS_OK : NS_ERROR_FAILURE;

 }

 nsresult

 nsTransactionItem::GetNumberOfRedoItems(int32_t *aNumItems)

 {

   NS_ENSURE_TRUE(aNumItems, NS_ERROR_NULL_POINTER);

   if (!mRedoStack) {

     *aNumItems = 0;

     return NS_OK;

   }

   *aNumItems = mRedoStack->GetSize();

   return *aNumItems ? NS_OK : NS_ERROR_FAILURE;

 }

 nsresult

 nsTransactionItem::RecoverFromUndoError(nsTransactionManager *aTxMgr)

 {

   //

   // If this method gets called, we never got to the point where we

   // successfully called UndoTransaction() for the transaction item itself.

   // Just redo any children that successfully called undo!

   //

   return RedoChildren(aTxMgr);

 }

 nsresult

 nsTransactionItem::RecoverFromRedoError(nsTransactionManager *aTxMgr)

 {

   //

   // If this method gets called, we already successfully called

   // RedoTransaction() for the transaction item itself. Undo all

   // the children that successfully called RedoTransaction(),

   // then undo the transaction item itself.

   //

   nsresult result;

   result = UndoChildren(aTxMgr);

   if (NS_FAILED(result)) {

     return result;

   }

   if (!mTransaction)

     return NS_OK;

   return mTransaction->UndoTransaction();

 }