1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of Qt Creator.
**
** 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 Digia. For licensing terms and
** conditions see http://www.qt.io/licensing. For further information
** use the contact form at http://www.qt.io/contact-us.
**
** 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 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
****************************************************************************/
#include "main.h"
#include <QApplication>
MyMain::MyMain(QWidget *parent, Qt::WFlags flags)
: QWidget(parent, flags)
{
ui.setupUi(this);
connect(ui.comboBox, SIGNAL(currentIndexChanged(int)), this, SLOT(select(int)));
}
void MyMain::add(IComboEntry *obj)
{
m_entries.append(obj);
ui.comboBox->addItem(obj->title());
}
void MyMain::select(int index)
{
IComboEntry *entry = m_entries.at(index);
// with multiple inheritance we would use qobject_cast here
// instead we use query, to get the components if they exist
IText1 *t1 = Aggregation::query<IText1>(entry);
IText2 *t2 = Aggregation::query<IText2>(entry);
IText3 *t3 = Aggregation::query<IText3>(entry);
// set the label texts and enable/disable, depending on whether
// the respective interface implementations exist
ui.text1->setText(t1 ? t1->text() : tr("N/A"));
ui.text2->setText(t2 ? t2->text() : tr("N/A"));
ui.text3->setText(t3 ? t3->text() : tr("N/A"));
ui.text1->setEnabled(t1);
ui.text2->setEnabled(t2);
ui.text3->setEnabled(t3);
}
MyMain::~MyMain()
{
// the following deletes all the Aggregate and IComboEntry and ITextX
// objects, as well as any other components we might have added
qDeleteAll(m_entries);
}
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MyMain w;
// create and set up some objects
// the first does only implement the required IComboEntry
// we don't need an aggregation for this
IComboEntry *obj1 = new IComboEntry("Entry without text");
// the second additionally provides an IText2 implementation
// adding a component to the aggregation is done by setting the aggregation as the parent of the component
Aggregation::Aggregate *obj2 = new Aggregation::Aggregate;
obj2->add(new IComboEntry("Entry with text 2"));
obj2->add(new IText2("This is a text for label 2"));
// and so on... two more objects...
Aggregation::Aggregate *obj3 = new Aggregation::Aggregate;
obj3->add(new IComboEntry("Entry with text 1 and 2"));
obj3->add(new IText1("I love Qt!"));
obj3->add(new IText2("There are software companies..."));
Aggregation::Aggregate *obj4 = new Aggregation::Aggregate;
obj4->add(new IComboEntry("Entry with text 1 and 3"));
obj4->add(new IText1("Some text written here."));
obj4->add(new IText3("I'm a troll."));
// the API takes IComboEntries, so we convert the them to it
// the MyMain object takes the ownership of the whole aggregations
w.add(Aggregation::query<IComboEntry>(obj1));
w.add(Aggregation::query<IComboEntry>(obj2));
w.add(Aggregation::query<IComboEntry>(obj3));
w.add(Aggregation::query<IComboEntry>(obj4));
w.show();
return app.exec();
}
|
