Home · All Classes · Main Classes · Grouped Classes · Modules · Functions

commands.cpp Example File
^{tools/undoframework/commands.cpp}

 /****************************************************************************
 **
 ** Copyright (C) 2007-2008 Trolltech ASA. All rights reserved.
 **
 ** This file is part of the documentation of the Qt Toolkit.
 **
 ** This file may be used under the terms of the GNU General Public
** License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the files LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file.  Alternatively you may (at
** your option) use any later version of the GNU General Public
** License if such license has been publicly approved by Trolltech ASA
** (or its successors, if any) and the KDE Free Qt Foundation. In
** addition, as a special exception, Trolltech gives you certain
** additional rights. These rights are described in the Trolltech GPL
** Exception version 1.2, which can be found at
** http://www.trolltech.com/products/qt/gplexception/ and in the file
** GPL_EXCEPTION.txt in this package.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/. If
** you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at [email protected].
**
** In addition, as a special exception, Trolltech, as the sole
** copyright holder for Qt Designer, grants users of the Qt/Eclipse
** Integration plug-in the right for the Qt/Eclipse Integration to
** link to functionality provided by Qt Designer and its related
** libraries.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not expressly
** granted herein.
 **
 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 **
 ****************************************************************************/

 #include <QtGui>

 #include "commands.h"
 #include "diagramitem.h"

 MoveCommand::MoveCommand(DiagramItem *diagramItem, const QPointF &oldPos,
                  QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     myDiagramItem = diagramItem;
     newPos = diagramItem->pos();
     myOldPos = oldPos;
 }

 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;
 }

 void MoveCommand::undo()
 {
     myDiagramItem->setPos(myOldPos);
     myDiagramItem->scene()->update();
     setText(QObject::tr("Move %1")
         .arg(createCommandString(myDiagramItem, newPos)));
 }

 void MoveCommand::redo()
 {
     myDiagramItem->setPos(newPos);
     setText(QObject::tr("Move %1")
         .arg(createCommandString(myDiagramItem, newPos)));
 }

 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())));
 }

 void DeleteCommand::undo()
 {
     myGraphicsScene->addItem(myDiagramItem);
     myGraphicsScene->update();
 }

 void DeleteCommand::redo()
 {
     myGraphicsScene->removeItem(myDiagramItem);
 }

 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)));
 }

 void AddCommand::undo()
 {
     myGraphicsScene->removeItem(myDiagramItem);
     myGraphicsScene->update();
 }

 void AddCommand::redo()
 {
     myGraphicsScene->addItem(myDiagramItem);
     myDiagramItem->setPos(initialPosition);
     myGraphicsScene->clearSelection();
     myGraphicsScene->update();
 }

 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());
 }