1/****************************************************************************
2**
3** Copyright (C) 2016 The Qt Company Ltd.
4** Contact: https://www.qt.io/licensing/
5**
6** This file is part of the examples of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:BSD$
9** Commercial License Usage
10** Licensees holding valid commercial Qt licenses may use this file in
11** accordance with the commercial license agreement provided with the
12** Software or, alternatively, in accordance with the terms contained in
13** a written agreement between you and The Qt Company. For licensing terms
14** and conditions see https://www.qt.io/terms-conditions. For further
15** information use the contact form at https://www.qt.io/contact-us.
16**
17** BSD License Usage
18** Alternatively, you may use this file under the terms of the BSD license
19** as follows:
20**
21** "Redistribution and use in source and binary forms, with or without
22** modification, are permitted provided that the following conditions are
23** met:
24** * Redistributions of source code must retain the above copyright
25** notice, this list of conditions and the following disclaimer.
26** * Redistributions in binary form must reproduce the above copyright
27** notice, this list of conditions and the following disclaimer in
28** the documentation and/or other materials provided with the
29** distribution.
30** * Neither the name of The Qt Company Ltd nor the names of its
31** contributors may be used to endorse or promote products derived
32** from this software without specific prior written permission.
33**
34**
35** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
36** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
37** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
38** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
39** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
42** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
43** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
44** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
45** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
46**
47** $QT_END_LICENSE$
48**
49****************************************************************************/
50
51#include "commands.h"
52#include "diagramitem.h"
53
54#include <QGraphicsScene>
55
56//! [0]
57MoveCommand::MoveCommand(DiagramItem *diagramItem, const QPointF &oldPos,
58 QUndoCommand *parent)
59 : QUndoCommand(parent), myDiagramItem(diagramItem)
60 , myOldPos(oldPos), newPos(diagramItem->pos())
61{
62}
63//! [0]
64
65//! [1]
66bool MoveCommand::mergeWith(const QUndoCommand *command)
67{
68 const MoveCommand *moveCommand = static_cast<const MoveCommand *>(command);
69 DiagramItem *item = moveCommand->myDiagramItem;
70
71 if (myDiagramItem != item)
72 return false;
73
74 newPos = item->pos();
75 setText(QObject::tr(s: "Move %1")
76 .arg(a: createCommandString(item: myDiagramItem, point: newPos)));
77
78 return true;
79}
80//! [1]
81
82//! [2]
83void MoveCommand::undo()
84{
85 myDiagramItem->setPos(myOldPos);
86 myDiagramItem->scene()->update();
87 setText(QObject::tr(s: "Move %1")
88 .arg(a: createCommandString(item: myDiagramItem, point: newPos)));
89}
90//! [2]
91
92//! [3]
93void MoveCommand::redo()
94{
95 myDiagramItem->setPos(newPos);
96 setText(QObject::tr(s: "Move %1")
97 .arg(a: createCommandString(item: myDiagramItem, point: newPos)));
98}
99//! [3]
100
101//! [4]
102DeleteCommand::DeleteCommand(QGraphicsScene *scene, QUndoCommand *parent)
103 : QUndoCommand(parent), myGraphicsScene(scene)
104{
105 QList<QGraphicsItem *> list = myGraphicsScene->selectedItems();
106 list.first()->setSelected(false);
107 myDiagramItem = static_cast<DiagramItem *>(list.first());
108 setText(QObject::tr(s: "Delete %1")
109 .arg(a: createCommandString(item: myDiagramItem, point: myDiagramItem->pos())));
110}
111//! [4]
112
113//! [5]
114void DeleteCommand::undo()
115{
116 myGraphicsScene->addItem(item: myDiagramItem);
117 myGraphicsScene->update();
118}
119//! [5]
120
121//! [6]
122void DeleteCommand::redo()
123{
124 myGraphicsScene->removeItem(item: myDiagramItem);
125}
126//! [6]
127
128//! [7]
129AddCommand::AddCommand(DiagramItem::DiagramType addType,
130 QGraphicsScene *scene, QUndoCommand *parent)
131 : QUndoCommand(parent), myGraphicsScene(scene)
132{
133 static int itemCount = 0;
134
135 myDiagramItem = new DiagramItem(addType);
136 initialPosition = QPointF((itemCount * 15) % int(scene->width()),
137 (itemCount * 15) % int(scene->height()));
138 scene->update();
139 ++itemCount;
140 setText(QObject::tr(s: "Add %1")
141 .arg(a: createCommandString(item: myDiagramItem, point: initialPosition)));
142}
143//! [7]
144
145AddCommand::~AddCommand()
146{
147 if (!myDiagramItem->scene())
148 delete myDiagramItem;
149}
150
151//! [8]
152void AddCommand::undo()
153{
154 myGraphicsScene->removeItem(item: myDiagramItem);
155 myGraphicsScene->update();
156}
157//! [8]
158
159//! [9]
160void AddCommand::redo()
161{
162 myGraphicsScene->addItem(item: myDiagramItem);
163 myDiagramItem->setPos(initialPosition);
164 myGraphicsScene->clearSelection();
165 myGraphicsScene->update();
166}
167//! [9]
168
169QString createCommandString(DiagramItem *item, const QPointF &pos)
170{
171 return QObject::tr(s: "%1 at (%2, %3)")
172 .arg(a: item->diagramType() == DiagramItem::Box ? "Box" : "Triangle")
173 .arg(a: pos.x()).arg(a: pos.y());
174}
175

source code of qtbase/examples/widgets/tools/undoframework/commands.cpp