gecko-dev/editor/libeditor/DeleteNodeTransaction.h

/* -*- 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/. */

#ifndef DeleteNodeTransaction_h
#define DeleteNodeTransaction_h

#include "mozilla/EditTransactionBase.h"
#include "nsCOMPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsIContent.h"
#include "nsINode.h"
#include "nsISupportsImpl.h"
#include "nscore.h"

namespace mozilla {

class EditorBase;

/**
 * A transaction that deletes a single element
 */
class DeleteNodeTransaction final : public EditTransactionBase
{
protected:
  DeleteNodeTransaction(EditorBase& aEditorBase, nsINode& aNodeToDelete);

public:
  /**
   * Creates a delete node transaction instance.  This returns nullptr if
   * it cannot remove the node from its parent.
   *
   * @param aEditorBase         The editor.
   * @param aNodeToDelete       The node to be removed from the DOM tree.
   */
  static already_AddRefed<DeleteNodeTransaction>
  MaybeCreate(EditorBase& aEditorBase, nsINode& aNodeToDelete);

  /**
   * CanDoIt() returns true if there are enough members and can modify the
   * parent.  Otherwise, false.
   */
  bool CanDoIt() const;

  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteNodeTransaction,
                                           EditTransactionBase)

  NS_DECL_EDITTRANSACTIONBASE

  NS_IMETHOD RedoTransaction() override;

protected:
  virtual ~DeleteNodeTransaction();

  // The editor for this transaction.
  RefPtr<EditorBase> mEditorBase;

  // The element to delete.
  nsCOMPtr<nsINode> mNodeToDelete;

  // Parent of node to delete.
  nsCOMPtr<nsINode> mParentNode;

  // Next sibling to remember for undo/redo purposes.
  nsCOMPtr<nsIContent> mRefNode;
};

} // namespace mozilla

#endif // #ifndef DeleteNodeTransaction_h