added icon in system tray

mainwindow.h

@@ -39,6 +39,8 @@
 #include <QProcess>
 #include <QToolBar>
 #include <QDir>
+#include <QSystemTrayIcon>
+#include <QMenu>
 
 QT_BEGIN_NAMESPACE
 namespace Ui { class MainWindow; }
@@ -98,6 +100,7 @@ class MainWindow : public QMainWindow
         QDialog Configuration;
         Ui::Configuration config;
         std::vector <QString> serversList;
+        QSystemTrayIcon * trayIcon;
         QList<QString> bwUnitText {
             "KB",
             "MB",
@@ -139,6 +142,9 @@ class MainWindow : public QMainWindow
         void saveDownloadList();
         void loadDownloadList();
         void download();
+        void initSystemTrayIcon();
+        void hideWindow();
+        void showWindow();
 
     private slots:
 
@@ -180,7 +186,13 @@ class MainWindow : public QMainWindow
 
         void cancelled(QProcess *);
 
-    signals:
+        void on_trayIcon_clicked(QSystemTrayIcon::ActivationReason reason);
+
+        void quitApp();
+
+        void on_actionExit_triggered();
+
+signals:
         void stopDownloading(QProcess *);
         void progressSignal(int);
         void finishedSignal(bool = true);