gecko-dev/editor/libeditor/CreateElementTransaction.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 "CreateElementTransaction.h"

#include <algorithm>
#include <stdio.h>

#include "mozilla/dom/Element.h"
#include "mozilla/dom/Selection.h"

#include "mozilla/Casting.h"
#include "mozilla/EditorBase.h"
#include "mozilla/EditorDOMPoint.h"

#include "nsAlgorithm.h"
#include "nsAString.h"
#include "nsDebug.h"
#include "nsError.h"
#include "nsIContent.h"
#include "nsIEditor.h"
#include "nsINode.h"
#include "nsISupportsUtils.h"
#include "nsMemory.h"
#include "nsReadableUtils.h"
#include "nsStringFwd.h"
#include "nsString.h"

namespace mozilla {

using namespace dom;

CreateElementTransaction::CreateElementTransaction(
                            EditorBase& aEditorBase,
                            nsAtom& aTag,
                            const EditorRawDOMPoint& aPointToInsert)
  : EditTransactionBase()
  , mEditorBase(&aEditorBase)
  , mTag(&aTag)
  , mPointToInsert(aPointToInsert)
{
}

CreateElementTransaction::~CreateElementTransaction()
{
}

NS_IMPL_CYCLE_COLLECTION_INHERITED(CreateElementTransaction,
                                   EditTransactionBase,
                                   mEditorBase,
                                   mPointToInsert,
                                   mNewNode)

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


NS_IMETHODIMP
CreateElementTransaction::DoTransaction()
{
  if (NS_WARN_IF(!mEditorBase) || NS_WARN_IF(!mTag) ||
      NS_WARN_IF(!mPointToInsert.IsSet())) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  mNewNode = mEditorBase->CreateHTMLContent(mTag);
  NS_ENSURE_STATE(mNewNode);

  // Try to insert formatting whitespace for the new node:
  mEditorBase->MarkNodeDirty(GetAsDOMNode(mNewNode));

  // Insert the new node
  ErrorResult error;
  InsertNewNode(error);
  if (NS_WARN_IF(error.Failed())) {
    return error.StealNSResult();
  }

  // Only set selection to insertion point if editor gives permission
  if (!mEditorBase->GetShouldTxnSetSelection()) {
    // Do nothing - DOM range gravity will adjust selection
    return NS_OK;
  }

  RefPtr<Selection> selection = mEditorBase->GetSelection();
  NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);

  EditorRawDOMPoint afterNewNode(mNewNode);
  if (NS_WARN_IF(!afterNewNode.AdvanceOffset())) {
    // If mutation observer or mutation event listener moved or removed the
    // new node, we hit this case.  Should we use script blocker while we're
    // in this method?
    return NS_ERROR_FAILURE;
  }
  selection->Collapse(afterNewNode, error);
  if (error.Failed()) {
    NS_WARNING("selection could not be collapsed after insert");
    error.SuppressException();
  }
  return NS_OK;
}

void
CreateElementTransaction::InsertNewNode(ErrorResult& aError)
{
  if (mPointToInsert.IsSetAndValid()) {
    if (mPointToInsert.IsEndOfContainer()) {
      mPointToInsert.Container()->AppendChild(*mNewNode, aError);
      NS_WARNING_ASSERTION(!aError.Failed(), "Failed to append the new node");
      return;
    }
    mPointToInsert.Container()->InsertBefore(*mNewNode,
                                             mPointToInsert.GetChildAtOffset(),
                                             aError);
    NS_WARNING_ASSERTION(!aError.Failed(), "Failed to insert the new node");
    return;
  }

  if (NS_WARN_IF(mPointToInsert.GetChildAtOffset() &&
                 mPointToInsert.Container() !=
                   mPointToInsert.GetChildAtOffset()->GetParentNode())) {
    aError.Throw(NS_ERROR_FAILURE);
    return;
  }

  // If mPointToInsert has only offset and it's not valid, we need to treat
  // it as pointing end of the container.
  mPointToInsert.Container()->AppendChild(*mNewNode, aError);
  NS_WARNING_ASSERTION(!aError.Failed(), "Failed to append the new node");
}

NS_IMETHODIMP
CreateElementTransaction::UndoTransaction()
{
  if (NS_WARN_IF(!mEditorBase) || NS_WARN_IF(!mPointToInsert.IsSet())) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  ErrorResult error;
  mPointToInsert.Container()->RemoveChild(*mNewNode, error);
  if (NS_WARN_IF(error.Failed())) {
    return error.StealNSResult();
  }
  return NS_OK;
}

NS_IMETHODIMP
CreateElementTransaction::RedoTransaction()
{
  if (NS_WARN_IF(!mEditorBase) || NS_WARN_IF(!mPointToInsert.IsSet())) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  // First, reset mNewNode so it has no attributes or content
  // XXX We never actually did this, we only cleared mNewNode's contents if it
  // was a CharacterData node (which it's not, it's an Element)
  // XXX Don't we need to set selection like DoTransaction()?

  // Now, reinsert mNewNode
  ErrorResult error;
  InsertNewNode(error);
  if (NS_WARN_IF(error.Failed())) {
    return error.StealNSResult();
  }
  return NS_OK;
}

NS_IMETHODIMP
CreateElementTransaction::GetTxnDescription(nsAString& aString)
{
  aString.AssignLiteral("CreateElementTransaction: ");
  aString += nsDependentAtomString(mTag);
  return NS_OK;
}

already_AddRefed<Element>
CreateElementTransaction::GetNewNode()
{
  return nsCOMPtr<Element>(mNewNode).forget();
}

} // namespace mozilla