- Qt 5.5
- Qt Widgets
- Undo Framework Example
- commands.h Example File
- Qt 5.5.1 Reference Documentation

# commands.h Example File

tools/undoframework/commands.h

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
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    **     from this software without specific prior written permission.
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    #ifndef COMMANDS_H
    #define COMMANDS_H

    #include <QUndoCommand>

    #include "diagramitem.h"

    class MoveCommand : public QUndoCommand
    {
    public:
        enum { Id = 1234 };

        MoveCommand(DiagramItem *diagramItem, const QPointF &oldPos,
                    QUndoCommand *parent = 0);

        void undo() Q_DECL_OVERRIDE;
        void redo() Q_DECL_OVERRIDE;
        bool mergeWith(const QUndoCommand *command) Q_DECL_OVERRIDE;
        int id() const Q_DECL_OVERRIDE { return Id; }

    private:
        DiagramItem *myDiagramItem;
        QPointF myOldPos;
        QPointF newPos;
    };

    class DeleteCommand : public QUndoCommand
    {
    public:
        explicit DeleteCommand(QGraphicsScene *graphicsScene, QUndoCommand *parent = 0);

        void undo() Q_DECL_OVERRIDE;
        void redo() Q_DECL_OVERRIDE;

    private:
        DiagramItem *myDiagramItem;
        QGraphicsScene *myGraphicsScene;
    };

    class AddCommand : public QUndoCommand
    {
    public:
        AddCommand(DiagramItem::DiagramType addType, QGraphicsScene *graphicsScene,
                   QUndoCommand *parent = 0);
        ~AddCommand();

        void undo() Q_DECL_OVERRIDE;
        void redo() Q_DECL_OVERRIDE;

    private:
        DiagramItem *myDiagramItem;
        QGraphicsScene *myGraphicsScene;
        QPointF initialPosition;
    };

    QString createCommandString(DiagramItem *item, const QPointF &point);

    #endif