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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0 WITH Qt-GPL-exception-1.0
#include "main.h"
#include <QApplication>
MyMain::MyMain(QWidget *parent, Qt::WFlags flags)
: QWidget(parent, flags)
{
ui.setupUi(this);
connect(ui.comboBox, QOverload<int>::of(&QComboBox::currentIndexChanged),
this, &MyMain::select);
}
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();
}
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