examples: Connect Quit action to QCoreApplication::quit, not QWidget::close

Change-Id: I44ca7b61a4a261a7d3aad0dfeb870eb927ee768d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit 850ef55fc57e62b70bab72705038e671002ca86e)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

examples/network/broadcastreceiver/receiver.cpp

@@ -5,6 +5,7 @@
 #include <QPushButton>
 #include <QUdpSocket>
 #include <QVBoxLayout>
+#include <QCoreApplication>
 
 #include "receiver.h"
 
@@ -26,7 +27,7 @@ Receiver::Receiver(QWidget *parent)
             this, &Receiver::processPendingDatagrams);
 //! [1]
     connect(quitButton, &QPushButton::clicked,
-            this, &Receiver::close);
+            qApp, &QCoreApplication::quit);
 
     auto buttonLayout = new QHBoxLayout;
     buttonLayout->addStretch(1);

examples/network/broadcastsender/sender.cpp

@@ -25,7 +25,7 @@ Sender::Sender(QWidget *parent)
 //! [0]
 
     connect(startButton, &QPushButton::clicked, this, &Sender::startBroadcasting);
-    connect(quitButton, &QPushButton::clicked, this, &Sender::close);
+    connect(quitButton, &QPushButton::clicked, qApp, &QCoreApplication::quit);
     connect(&timer, &QTimer::timeout, this, &Sender::broadcastDatagram);
 
     auto mainLayout = new QVBoxLayout;

examples/network/loopback/dialog.cpp

@@ -25,7 +25,7 @@ Dialog::Dialog(QWidget *parent)
     buttonBox->addButton(quitButton, QDialogButtonBox::RejectRole);
 
     connect(startButton, &QAbstractButton::clicked, this, &Dialog::start);
-    connect(quitButton, &QAbstractButton::clicked, this, &QWidget::close);
+    connect(quitButton, &QAbstractButton::clicked, qApp, &QCoreApplication::quit);
     connect(&tcpServer, &QTcpServer::newConnection,
             this, &Dialog::acceptConnection);
     connect(&tcpClient, &QAbstractSocket::connected, this, &Dialog::startTransfer);

examples/network/multicastreceiver/receiver.cpp

@@ -38,7 +38,7 @@ Receiver::Receiver(QWidget *parent)
     connect(&udpSocket6, &QUdpSocket::readyRead,
             this, &Receiver::processPendingDatagrams);
     connect(quitButton, &QPushButton::clicked,
-            this, &Receiver::close);
+            qApp, &QCoreApplication::quit);
 }
 
 void Receiver::processPendingDatagrams()

examples/sql/books/bookwindow.cpp

@@ -111,7 +111,7 @@ void BookWindow::createMenuBar()
     helpMenu->addAction(aboutAction);
     helpMenu->addAction(aboutQtAction);
 
-    connect(quitAction, &QAction::triggered, this, &BookWindow::close);
+    connect(quitAction, &QAction::triggered, qApp, &QCoreApplication::quit);
     connect(aboutAction, &QAction::triggered, this, &BookWindow::about);
     connect(aboutQtAction, &QAction::triggered, qApp, &QApplication::aboutQt);
 }

examples/sql/masterdetail/mainwindow.cpp

@@ -341,7 +341,7 @@ void MainWindow::createMenuBar()
     connect(deleteAction, &QAction::triggered,
             this, &MainWindow::deleteAlbum);
     connect(quitAction, &QAction::triggered,
-            this, &MainWindow::close);
+            qApp, &QCoreApplication::quit);
     connect(aboutAction, &QAction::triggered,
             this, &MainWindow::about);
     connect(aboutQtAction, &QAction::triggered,

examples/widgets/mainwindows/dockwidgets/mainwindow.cpp

@@ -215,7 +215,7 @@ void MainWindow::createActions()
 
     fileMenu->addSeparator();
 
-    QAction *quitAct = fileMenu->addAction(tr("&Quit"), this, &QWidget::close);
+    QAction *quitAct = fileMenu->addAction(tr("&Quit"), qApp, &QCoreApplication::quit);
     quitAct->setShortcuts(QKeySequence::Quit);
     quitAct->setStatusTip(tr("Quit the application"));
 

examples/widgets/mainwindows/mainwindow/mainwindow.cpp

@@ -93,7 +93,7 @@ void MainWindow::setupMenuBar()
     menu->addAction(tr("Switch layout direction"),this, &MainWindow::switchLayoutDirection);
 
     menu->addSeparator();
-    menu->addAction(tr("&Quit"), this, &QWidget::close);
+    menu->addAction(tr("&Quit"), qApp, &QCoreApplication::quit);
 
     mainWindowMenu = menuBar()->addMenu(tr("Main window"));
 

examples/widgets/richtext/textedit/textedit.cpp

@@ -171,7 +171,7 @@ void TextEdit::setupFileActions()
     menu->addSeparator();
 #endif
 
-    a = menu->addAction(tr("&Quit"), this, &QWidget::close);
+    a = menu->addAction(tr("&Quit"), qApp, &QCoreApplication::quit);
     a->setShortcut(Qt::CTRL | Qt::Key_Q);
 }
 

examples/widgets/widgets/icons/mainwindow.cpp

@@ -417,7 +417,7 @@ void MainWindow::createActions()
 
     fileMenu->addSeparator();
 
-    QAction *exitAct = fileMenu->addAction(tr("&Quit"), this, &QWidget::close);
+    QAction *exitAct = fileMenu->addAction(tr("&Quit"), qApp, &QCoreApplication::quit);
     exitAct->setShortcuts(QKeySequence::Quit);
 
     QMenu *viewMenu = menuBar()->addMenu(tr("&View"));