Use proper method for deferred calls

src/app/application.cpp

@@ -47,6 +47,7 @@
 #include <QByteArray>
 #include <QDebug>
 #include <QLibraryInfo>
+#include <QMetaObject>
 #include <QProcess>
 
 #ifndef DISABLE_GUI
@@ -770,7 +771,7 @@ void Application::shutdownCleanup(QSessionManager &manager)
     // According to the qt docs we shouldn't call quit() inside a slot.
     // aboutToQuit() is never emitted if the user hits "Cancel" in
     // the above dialog.
-    QTimer::singleShot(0, qApp, &QCoreApplication::quit);
+    QMetaObject::invokeMethod(qApp, &QCoreApplication::quit, Qt::QueuedConnection);
 }
 #endif
 

src/base/search/searchhandler.cpp

@@ -29,6 +29,7 @@
 
 #include "searchhandler.h"
 
+#include <QMetaObject>
 #include <QProcess>
 #include <QTimer>
 #include <QVector>
@@ -87,7 +88,8 @@ SearchHandler::SearchHandler(const QString &pattern, const QString &category, co
     m_searchTimeout->start(180000); // 3 min
 
     // deferred start allows clients to handle starting-related signals
-    QTimer::singleShot(0, this, [this]() { m_searchProcess->start(QIODevice::ReadOnly); });
+    QMetaObject::invokeMethod(this, [this]() { m_searchProcess->start(QIODevice::ReadOnly); }
+        , Qt::QueuedConnection);
 }
 
 bool SearchHandler::isActive() const

src/gui/mainwindow.cpp

@@ -40,6 +40,7 @@
 #include <QFileSystemWatcher>
 #include <QKeyEvent>
 #include <QMessageBox>
+#include <QMetaObject>
 #include <QMimeData>
 #include <QProcess>
 #include <QPushButton>
@@ -348,8 +349,7 @@ MainWindow::MainWindow(QWidget *parent)
     on_actionWarningMessages_triggered(m_ui->actionWarningMessages->isChecked());
     on_actionCriticalMessages_triggered(m_ui->actionCriticalMessages->isChecked());
     if (m_ui->actionSearchWidget->isChecked())
-        QTimer::singleShot(0, this, &MainWindow::on_actionSearchWidget_triggered);
+        QMetaObject::invokeMethod(this, &MainWindow::on_actionSearchWidget_triggered, Qt::QueuedConnection);
-
     // Auto shutdown actions
     auto *autoShutdownGroup = new QActionGroup(this);
     autoShutdownGroup->setExclusive(true);
@@ -1195,7 +1195,7 @@ void MainWindow::closeEvent(QCloseEvent *e)
     if (!m_forceExit && m_systrayIcon && goToSystrayOnExit && !this->isHidden())
     {
         e->ignore();
-        QTimer::singleShot(0, this, &QWidget::hide);
+        QMetaObject::invokeMethod(this, &QWidget::hide, Qt::QueuedConnection);
         if (!pref->closeToTrayNotified())
         {
             showNotificationBalloon(tr("qBittorrent is closed to tray"), tr("This behavior can be changed in the settings. You won't be reminded again."));
@@ -1292,7 +1292,7 @@ bool MainWindow::event(QEvent *e)
                 {
                     qDebug("Minimize to Tray enabled, hiding!");
                     e->ignore();
-                    QTimer::singleShot(0, this, &QWidget::hide);
+                    QMetaObject::invokeMethod(this, &QWidget::hide, Qt::QueuedConnection);
                     if (!pref->minimizeToTrayNotified())
                     {
                         showNotificationBalloon(tr("qBittorrent is minimized to tray"), tr("This behavior can be changed in the settings. You won't be reminded again."));