/* -*- 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 ChangeAttributeTransaction_h
#define ChangeAttributeTransaction_h

#include "EditTransactionBase.h"  // base class

#include "mozilla/Attributes.h"            // override
#include "nsCOMPtr.h"                      // nsCOMPtr members
#include "nsCycleCollectionParticipant.h"  // NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED
#include "nsISupportsImpl.h"               // NS_DECL_ISUPPORTS_INHERITED
#include "nsString.h"                      // nsString members

class nsAtom;

namespace mozilla {
namespace dom {
class Element;
}  // namespace dom

/**
 * A transaction that changes an attribute of a content node.  This transaction
 * covers add, remove, and change attribute.
 */
class ChangeAttributeTransaction final : public EditTransactionBase {
 protected:
  ChangeAttributeTransaction(dom::Element& aElement, nsAtom& aAttribute,
                             const nsAString* aValue);

 public:
  /**
   * Creates a change attribute transaction to set an attribute to something.
   * This method never returns nullptr.
   *
   * @param aElement    The element whose attribute will be changed.
   * @param aAttribute  The name of the attribute to change.
   * @param aValue      The new value for aAttribute.
   */
  static already_AddRefed<ChangeAttributeTransaction> Create(
      dom::Element& aElement, nsAtom& aAttribute, const nsAString& aValue);

  /**
   * Creates a change attribute transaction to remove an attribute.  This
   * method never returns nullptr.
   *
   * @param aElement    The element whose attribute will be changed.
   * @param aAttribute  The name of the attribute to remove.
   */
  static already_AddRefed<ChangeAttributeTransaction> CreateToRemove(
      dom::Element& aElement, nsAtom& aAttribute);

  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeAttributeTransaction,
                                           EditTransactionBase)

  NS_DECL_EDITTRANSACTIONBASE
  NS_DECL_EDITTRANSACTIONBASE_GETASMETHODS_OVERRIDE(ChangeAttributeTransaction)

  MOZ_CAN_RUN_SCRIPT NS_IMETHOD RedoTransaction() override;

  friend std::ostream& operator<<(
      std::ostream& aStream, const ChangeAttributeTransaction& aTransaction);

 private:
  virtual ~ChangeAttributeTransaction() = default;

  // The element to operate upon
  nsCOMPtr<dom::Element> mElement;

  // The attribute to change
  RefPtr<nsAtom> mAttribute;

  // The value to set the attribute to (ignored if mRemoveAttribute==true)
  nsString mValue;

  // The value to set the attribute to for undo
  nsString mUndoValue;

  // True if the operation is to remove mAttribute from mElement
  bool mRemoveAttribute;

  // True if the mAttribute was set on mElement at the time of execution
  bool mAttributeWasSet;
};

}  // namespace mozilla

#endif  // #ifndef ChangeAttributeTransaction_h