gecko-dev/editor/libeditor/DeleteNodeTransaction.cpp

/* -*- 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 "DeleteNodeTransaction.h"
#include "mozilla/EditorBase.h"
#include "mozilla/SelectionState.h" // RangeUpdater
#include "nsDebug.h"
#include "nsError.h"
#include "nsAString.h"

namespace mozilla {

DeleteNodeTransaction::DeleteNodeTransaction()
  : mEditorBase(nullptr)
  , mRangeUpdater(nullptr)
{
}

DeleteNodeTransaction::~DeleteNodeTransaction()
{
}

NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteNodeTransaction, EditTransactionBase,
                                   mNode,
                                   mParent,
                                   mRefNode)

NS_IMPL_ADDREF_INHERITED(DeleteNodeTransaction, EditTransactionBase)
NS_IMPL_RELEASE_INHERITED(DeleteNodeTransaction, EditTransactionBase)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeleteNodeTransaction)
NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)

nsresult
DeleteNodeTransaction::Init(EditorBase* aEditorBase,
                            nsINode* aNode,
                            RangeUpdater* aRangeUpdater)
{
  NS_ENSURE_TRUE(aEditorBase && aNode, NS_ERROR_NULL_POINTER);
  mEditorBase = aEditorBase;
  mNode = aNode;
  mParent = aNode->GetParentNode();

  // do nothing if the node has a parent and it's read-only
  NS_ENSURE_TRUE(!mParent || mEditorBase->IsModifiableNode(mParent),
                 NS_ERROR_FAILURE);

  mRangeUpdater = aRangeUpdater;
  return NS_OK;
}

NS_IMETHODIMP
DeleteNodeTransaction::DoTransaction()
{
  NS_ENSURE_TRUE(mNode, NS_ERROR_NOT_INITIALIZED);

  if (!mParent) {
    // this is a no-op, there's no parent to delete mNode from
    return NS_OK;
  }

  // remember which child mNode was (by remembering which child was next);
  // mRefNode can be null
  mRefNode = mNode->GetNextSibling();

  // give range updater a chance.  SelAdjDeleteNode() needs to be called
  // *before* we do the action, unlike some of the other RangeItem update
  // methods.
  if (mRangeUpdater) {
    mRangeUpdater->SelAdjDeleteNode(mNode->AsDOMNode());
  }

  ErrorResult error;
  mParent->RemoveChild(*mNode, error);
  return error.StealNSResult();
}

NS_IMETHODIMP
DeleteNodeTransaction::UndoTransaction()
{
  if (!mParent) {
    // this is a legal state, the txn is a no-op
    return NS_OK;
  }
  if (!mNode) {
    return NS_ERROR_NULL_POINTER;
  }

  ErrorResult error;
  nsCOMPtr<nsIContent> refNode = mRefNode;
  mParent->InsertBefore(*mNode, refNode, error);
  return error.StealNSResult();
}

NS_IMETHODIMP
DeleteNodeTransaction::RedoTransaction()
{
  if (!mParent) {
    // this is a legal state, the txn is a no-op
    return NS_OK;
  }
  if (!mNode) {
    return NS_ERROR_NULL_POINTER;
  }

  if (mRangeUpdater) {
    mRangeUpdater->SelAdjDeleteNode(mNode->AsDOMNode());
  }

  ErrorResult error;
  mParent->RemoveChild(*mNode, error);
  return error.StealNSResult();
}

NS_IMETHODIMP
DeleteNodeTransaction::GetTxnDescription(nsAString& aString)
{
  aString.AssignLiteral("DeleteNodeTransaction");
  return NS_OK;
}

} // namespace mozilla