commands.cpp Example File

tools/undoframework/commands.cpp
/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/
#include <QtWidgets> #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))); } AddCommand::~AddCommand() { if (!myDiagramItem->scene()) delete myDiagramItem; } 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()); }