1 /****************************************************************************

     2 **

     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

     4 ** All rights reserved.

     5 ** Contact: Nokia Corporation (qt-info@nokia.com)

     6 **

     7 ** This file is part of the examples of the Qt Toolkit.

     8 **

     9 ** $QT_BEGIN_LICENSE:LGPL$

    10 ** No Commercial Usage

    11 ** This file contains pre-release code and may not be distributed.

    12 ** You may use this file in accordance with the terms and conditions

    13 ** contained in the Technology Preview License Agreement accompanying

    14 ** this package.

    15 **

    16 ** GNU Lesser General Public License Usage

    17 ** Alternatively, this file may be used under the terms of the GNU Lesser

    18 ** General Public License version 2.1 as published by the Free Software

    19 ** Foundation and appearing in the file LICENSE.LGPL included in the

    20 ** packaging of this file.  Please review the following information to

    21 ** ensure the GNU Lesser General Public License version 2.1 requirements

    22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

    23 **

    24 ** In addition, as a special exception, Nokia gives you certain additional

    25 ** rights.  These rights are described in the Nokia Qt LGPL Exception

    26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

    27 **

    28 ** If you have questions regarding the use of this file, please contact

    29 ** Nokia at qt-info@nokia.com.

    30 **

    31 **

    32 **

    33 **

    34 **

    35 **

    36 **

    37 **

    38 ** $QT_END_LICENSE$

    39 **

    40 ****************************************************************************/

    41 

    42 #include <QtGui>

    43 

    44 #include "commands.h"

    45 #include "diagramitem.h"

    46 

    47 //! [0]

    48 MoveCommand::MoveCommand(DiagramItem *diagramItem, const QPointF &oldPos,

    49                  QUndoCommand *parent)

    50     : QUndoCommand(parent)

    51 {

    52     myDiagramItem = diagramItem;

    53     newPos = diagramItem->pos();

    54     myOldPos = oldPos;

    55 }

    56 //! [0]

    57 

    58 //! [1]

    59 bool MoveCommand::mergeWith(const QUndoCommand *command)

    60 {

    61     const MoveCommand *moveCommand = static_cast<const MoveCommand *>(command);

    62     DiagramItem *item = moveCommand->myDiagramItem;

    63 

    64     if (myDiagramItem != item)

    65     return false;

    66 

    67     newPos = item->pos();

    68     setText(QObject::tr("Move %1")

    69         .arg(createCommandString(myDiagramItem, newPos)));

    70 

    71     return true;

    72 }

    73 //! [1]

    74 

    75 //! [2]

    76 void MoveCommand::undo()

    77 {

    78     myDiagramItem->setPos(myOldPos);

    79     myDiagramItem->scene()->update();

    80     setText(QObject::tr("Move %1")

    81         .arg(createCommandString(myDiagramItem, newPos)));

    82 }

    83 //! [2]

    84 

    85 //! [3]

    86 void MoveCommand::redo()

    87 {

    88     myDiagramItem->setPos(newPos);

    89     setText(QObject::tr("Move %1")

    90         .arg(createCommandString(myDiagramItem, newPos)));

    91 }

    92 //! [3]

    93 

    94 //! [4]

    95 DeleteCommand::DeleteCommand(QGraphicsScene *scene, QUndoCommand *parent)

    96     : QUndoCommand(parent)

    97 {

    98     myGraphicsScene = scene;

    99     QList<QGraphicsItem *> list = myGraphicsScene->selectedItems();

   100     list.first()->setSelected(false);

   101     myDiagramItem = static_cast<DiagramItem *>(list.first());

   102     setText(QObject::tr("Delete %1")

   103         .arg(createCommandString(myDiagramItem, myDiagramItem->pos())));

   104 }

   105 //! [4]

   106 

   107 //! [5]

   108 void DeleteCommand::undo()

   109 {

   110     myGraphicsScene->addItem(myDiagramItem);

   111     myGraphicsScene->update();

   112 }

   113 //! [5]

   114 

   115 //! [6]

   116 void DeleteCommand::redo()

   117 {

   118     myGraphicsScene->removeItem(myDiagramItem);

   119 }

   120 //! [6]

   121 

   122 //! [7]

   123 AddCommand::AddCommand(DiagramItem::DiagramType addType,

   124                        QGraphicsScene *scene, QUndoCommand *parent)

   125     : QUndoCommand(parent)

   126 {

   127     static int itemCount = 0;

   128 

   129     myGraphicsScene = scene;

   130     myDiagramItem = new DiagramItem(addType);

   131     initialPosition = QPointF((itemCount * 15) % int(scene->width()),

   132                               (itemCount * 15) % int(scene->height()));

   133     scene->update();

   134     ++itemCount;

   135     setText(QObject::tr("Add %1")

   136         .arg(createCommandString(myDiagramItem, initialPosition)));

   137 }

   138 //! [7]

   139 

   140 //! [8]

   141 void AddCommand::undo()

   142 {

   143     myGraphicsScene->removeItem(myDiagramItem);

   144     myGraphicsScene->update();

   145 }

   146 //! [8]

   147 

   148 //! [9]

   149 void AddCommand::redo()

   150 {

   151     myGraphicsScene->addItem(myDiagramItem);

   152     myDiagramItem->setPos(initialPosition);

   153     myGraphicsScene->clearSelection();

   154     myGraphicsScene->update();

   155 }

   156 //! [9]

   157 

   158 QString createCommandString(DiagramItem *item, const QPointF &pos)

   159 {

   160     return QObject::tr("%1 at (%2, %3)")

   161         .arg(item->diagramType() == DiagramItem::Box ? "Box" : "Triangle")

   162         .arg(pos.x()).arg(pos.y());

   163 }