undocommand.h

/*
 * SPDX-FileCopyrightText: (C) 2020 Carl Schwan <carl@carlschwan.eu>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */
 
#pragma once
 
class QImage;
 
/**
 * A class implementing the command pattern. This is used to implemented various filters.
 */
class UndoCommand
{
public:
    virtual ~UndoCommand() = 0;
 
    /**
     * Applies the change to the document.
     */
    virtual QImage redo(QImage image) = 0;
 
    /**
     * Revert a change to the document.
     */
    virtual QImage undo(QImage image) = 0;
};