This is on the constructor:
Qt Code: 
  1. trayIcon = new QSystemTrayIcon(this);
  2.     trayIcon->setIcon(QIcon(":/icons/omg4.png"));
  3.     trayIcon->setToolTip("Wallpaper Changer \nDouble click to show the window.\nMiddle click to exit the application.\nRight click for some options.");
  4.     connect(trayIcon,SIGNAL(activated(QSystemTrayIcon::ActivationReason)),this,SLOT(clickSysTrayIcon(QSystemTrayIcon::ActivationReason)));
  5.     connect(this,SIGNAL(minimized()),this,SLOT(hide()),Qt::QueuedConnection);
  6.     QMenu *clock_menu = new QMenu;
  7.     //clock_menu->addAction("&Play",this,SLOT(playClicked()));
  8.     //clock_menu->addAction("P&ause",this,SLOT(pauseClicked()));
  9.     //clock_menu->addAction("St&op",this,SLOT(stopClicked()));
  10.     clock_menu->addAction("&Show",this,SLOT(showClicked()));
  11.     clock_menu->addAction("Se&ttings",this,SLOT(showSettings()));
  12.     clock_menu->addAction(QIcon(":/new/clock/clock.png"),"&About",this,SLOT(showAbout()));
  13.     clock_menu->addSeparator();
  14.     clock_menu->addAction("&Exit",qApp,SLOT(quit()));
  15.     trayIcon->setContextMenu(clock_menu);
To copy to clipboard, switch view to plain text mode 
This on the change event:
Qt Code: 
  1. switch (e->type()) {
  2.     case QEvent::LanguageChange:
  3.         ui->retranslateUi(this);
  4.         break;
  5.  
  6.     //see if the event is changing the window state
  7.     case QEvent::WindowStateChange:
  8.         //if it is, we need to see that this event is minimize
  9.  
  10.         if (isMinimized()) {
  11.             //EDWWWWWWWW
  12.             trayIcon->show();
  13.            // QCoreApplication::sendPostedEvents(QObject *trayIcon);
  14.             enum MessageIcon { NoIcon, Information, Warning, Critical };
  15.                        QSystemTrayIcon::MessageIcon icon = QSystemTrayIcon::MessageIcon(Information);
  16.  
  17.                        trayIcon->showMessage("titlos", "mplampla", icon, 10000);
  18.             emit minimized();}
  19.  
  20.     default:
  21.         break;
  22.  
  23.         QMainWindow::changeEvent(e); }
To copy to clipboard, switch view to plain text mode 
And this is the void function while it is minimized:
Qt Code: 
  1. void MainWindow::clickSysTrayIcon(QSystemTrayIcon::ActivationReason reason)
  2. {
  3.     //reason is a variable that holds the type of activation or click done on the icon tray
  4.     switch (reason) {
  5.     case QSystemTrayIcon::DoubleClick: //if it's a double click
  6.     //hide the icon
  7.     trayIcon->hide();
  8.     //show the main window
  9.     this->showNormal();
  10.     break;
  11.     case QSystemTrayIcon::MiddleClick:
  12.     //quit the application
  13.     qApp->quit();
  14.     break;
  15.     case QSystemTrayIcon::Unknown:
  16.     break;
  17.     case QSystemTrayIcon::Context:
  18.     break;
  19.     case QSystemTrayIcon::Trigger:
  20.     break;
  21.     default :
  22.             ;
  23.     }
  24. }
To copy to clipboard, switch view to plain text mode 
I don't know why but the message is shown on the left and not below the application's icon. Why is this happening and how can I fix it?