qt5base-lts/examples/tools/undoframework/commands.cpp

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/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** 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
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
** the names of its contributors may be used to endorse or promote
** products derived from this software without specific prior written
** permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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** $QT_END_LICENSE$
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****************************************************************************/
#include <QtWidgets>
#include "commands.h"
#include "diagramitem.h"
//! [0]
MoveCommand::MoveCommand(DiagramItem *diagramItem, const QPointF &oldPos,
QUndoCommand *parent)
: QUndoCommand(parent)
{
myDiagramItem = diagramItem;
newPos = diagramItem->pos();
myOldPos = oldPos;
}
//! [0]
//! [1]
bool MoveCommand::mergeWith(const QUndoCommand *command)
{
const MoveCommand *moveCommand = static_cast<const MoveCommand *>(command);
DiagramItem *item = moveCommand->myDiagramItem;
if (myDiagramItem != item)
return false;
newPos = item->pos();
setText(QObject::tr("Move %1")
.arg(createCommandString(myDiagramItem, newPos)));
return true;
}
//! [1]
//! [2]
void MoveCommand::undo()
{
myDiagramItem->setPos(myOldPos);
myDiagramItem->scene()->update();
setText(QObject::tr("Move %1")
.arg(createCommandString(myDiagramItem, newPos)));
}
//! [2]
//! [3]
void MoveCommand::redo()
{
myDiagramItem->setPos(newPos);
setText(QObject::tr("Move %1")
.arg(createCommandString(myDiagramItem, newPos)));
}
//! [3]
//! [4]
DeleteCommand::DeleteCommand(QGraphicsScene *scene, QUndoCommand *parent)
: QUndoCommand(parent)
{
myGraphicsScene = scene;
QList<QGraphicsItem *> list = myGraphicsScene->selectedItems();
list.first()->setSelected(false);
myDiagramItem = static_cast<DiagramItem *>(list.first());
setText(QObject::tr("Delete %1")
.arg(createCommandString(myDiagramItem, myDiagramItem->pos())));
}
//! [4]
//! [5]
void DeleteCommand::undo()
{
myGraphicsScene->addItem(myDiagramItem);
myGraphicsScene->update();
}
//! [5]
//! [6]
void DeleteCommand::redo()
{
myGraphicsScene->removeItem(myDiagramItem);
}
//! [6]
//! [7]
AddCommand::AddCommand(DiagramItem::DiagramType addType,
QGraphicsScene *scene, QUndoCommand *parent)
: QUndoCommand(parent)
{
static int itemCount = 0;
myGraphicsScene = scene;
myDiagramItem = new DiagramItem(addType);
initialPosition = QPointF((itemCount * 15) % int(scene->width()),
(itemCount * 15) % int(scene->height()));
scene->update();
++itemCount;
setText(QObject::tr("Add %1")
.arg(createCommandString(myDiagramItem, initialPosition)));
}
//! [7]
AddCommand::~AddCommand()
{
if (!myDiagramItem->scene())
delete myDiagramItem;
}
//! [8]
void AddCommand::undo()
{
myGraphicsScene->removeItem(myDiagramItem);
myGraphicsScene->update();
}
//! [8]
//! [9]
void AddCommand::redo()
{
myGraphicsScene->addItem(myDiagramItem);
myDiagramItem->setPos(initialPosition);
myGraphicsScene->clearSelection();
myGraphicsScene->update();
}
//! [9]
QString createCommandString(DiagramItem *item, const QPointF &pos)
{
return QObject::tr("%1 at (%2, %3)")
.arg(item->diagramType() == DiagramItem::Box ? "Box" : "Triangle")
.arg(pos.x()).arg(pos.y());
}