|  | 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 example classes 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 sales@trolltech.com.
     **
     ** 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());
     }