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#include <QtGui>

#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]

//! [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());

}