Signal/Slot Connections
/* signal-slot.cpp This file is part of GammaRay, the Qt application inspection and manipulation tool. Copyright (C) 2016-2020 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com Author: Volker Krause <volker.krause@kdab.com> Licensees holding valid commercial KDAB GammaRay licenses may use this file in accordance with GammaRay Commercial License Agreement provided with the Software. Contact info@kdab.com if any conditions of this licensing are not clear to you. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <QApplication> #include <QLCDNumber> #include <QPushButton> #include <QVBoxLayout> #include <QWidget> class Widget : public QWidget { Q_OBJECT public: explicit Widget(QWidget *parent = nullptr) : QWidget(parent) { auto layout = new QVBoxLayout(this); m_emitButton = new QPushButton("Emit Signal", this); layout->addWidget(m_emitButton); connect(m_emitButton, &QPushButton::clicked, this, &Widget::signalEmitted); auto reconnectButton = new QPushButton("Reconnect Signal", this); layout->addWidget(reconnectButton); connect(reconnectButton, &QPushButton::clicked, this, &Widget::reconnectSignal); m_counter = new QLCDNumber(this); layout->addWidget(m_counter); } public slots: void reconnectSignal() { disconnect(m_emitButton, &QPushButton::clicked, this, &Widget::signalEmitted); connect(m_emitButton, &QAbstractButton::clicked, this, &Widget::signalEmitted); } void signalEmitted() { m_counter->display(m_counter->intValue() + 1); } private: QPushButton *m_emitButton; QLCDNumber *m_counter; }; int main(int argc, char **argv) { QApplication app(argc, argv); Widget w; w.show(); return app.exec(); } #include "signal-slot.moc"