commands.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation ([email protected])
 **
 ** This file is part of the demonstration applications of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** No Commercial Usage
 ** This file contains pre-release code and may not be distributed.
 ** You may use this file in accordance with the terms and conditions
 ** contained in the Technology Preview License Agreement accompanying
 ** this package.
 **
 ** GNU Lesser General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU Lesser
 ** General Public License version 2.1 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.LGPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU Lesser General Public License version 2.1 requirements
 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
 ** In addition, as a special exception, Nokia gives you certain additional
 ** rights.  These rights are described in the Nokia Qt LGPL Exception
 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
 **
 ** If you have questions regarding the use of this file, please contact
 ** Nokia at [email protected].
 **
 **
 **
 **
 **
 **
 **
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "commands.h"

 static const int setShapeRectCommandId = 1;
 static const int setShapeColorCommandId = 2;

 /******************************************************************************
 ** AddShapeCommand
 */

 AddShapeCommand::AddShapeCommand(Document *doc, const Shape &shape, QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     m_doc = doc;
     m_shape = shape;
 }

 void AddShapeCommand::undo()
 {
     m_doc->deleteShape(m_shapeName);
 }

 void AddShapeCommand::redo()
 {
     // A shape only gets a name when it is inserted into a document
     m_shapeName = m_doc->addShape(m_shape);
     setText(QObject::tr("Add %1").arg(m_shapeName));
 }

 /******************************************************************************
 ** RemoveShapeCommand
 */

 RemoveShapeCommand::RemoveShapeCommand(Document *doc, const QString &shapeName,
                                         QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     setText(QObject::tr("Remove %1").arg(shapeName));
     m_doc = doc;
     m_shape = doc->shape(shapeName);
     m_shapeName = shapeName;
 }

 void RemoveShapeCommand::undo()
 {
     m_shapeName = m_doc->addShape(m_shape);
 }

 void RemoveShapeCommand::redo()
 {
     m_doc->deleteShape(m_shapeName);
 }

 /******************************************************************************
 ** SetShapeColorCommand
 */

 SetShapeColorCommand::SetShapeColorCommand(Document *doc, const QString &shapeName,
                                             const QColor &color, QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     setText(QObject::tr("Set %1's color").arg(shapeName));

     m_doc = doc;
     m_shapeName = shapeName;
     m_oldColor = doc->shape(shapeName).color();
     m_newColor = color;
 }

 void SetShapeColorCommand::undo()
 {
     m_doc->setShapeColor(m_shapeName, m_oldColor);
 }

 void SetShapeColorCommand::redo()
 {
     m_doc->setShapeColor(m_shapeName, m_newColor);
 }

 bool SetShapeColorCommand::mergeWith(const QUndoCommand *command)
 {
     if (command->id() != setShapeColorCommandId)
         return false;

     const SetShapeColorCommand *other = static_cast<const SetShapeColorCommand*>(command);
     if (m_shapeName != other->m_shapeName)
         return false;

     m_newColor = other->m_newColor;
     return true;
 }

 int SetShapeColorCommand::id() const
 {
     return setShapeColorCommandId;
 }

 /******************************************************************************
 ** SetShapeRectCommand
 */

 SetShapeRectCommand::SetShapeRectCommand(Document *doc, const QString &shapeName,
                                             const QRect &rect, QUndoCommand *parent)
     : QUndoCommand(parent)
 {
     setText(QObject::tr("Change %1's geometry").arg(shapeName));

     m_doc = doc;
     m_shapeName = shapeName;
     m_oldRect = doc->shape(shapeName).rect();
     m_newRect = rect;
 }

 void SetShapeRectCommand::undo()
 {
     m_doc->setShapeRect(m_shapeName, m_oldRect);
 }

 void SetShapeRectCommand::redo()
 {
     m_doc->setShapeRect(m_shapeName, m_newRect);
 }

 bool SetShapeRectCommand::mergeWith(const QUndoCommand *command)
 {
     if (command->id() != setShapeRectCommandId)
         return false;

     const SetShapeRectCommand *other = static_cast<const SetShapeRectCommand*>(command);
     if (m_shapeName != other->m_shapeName)
         return false;

     m_newRect = other->m_newRect;
     return true;
 }

 int SetShapeRectCommand::id() const
 {
     return setShapeRectCommandId;
 }