Hiding System Tray Icon with QSystemTrayIcon::hide() in Qt Widgets

Purpose

• Hides the application's icon from the system tray notification area. This is useful when you want to minimize the user's visual clutter or when your application no longer needs to be readily accessible from the tray.

Usage

1. #include <QtWidgets>
   

2. Create a QSystemTrayIcon object
   

   QSystemTrayIcon* trayIcon = new QSystemTrayIcon(this);
   

3. (Optional) Customize the icon
   

   • Use setIcon() to set the icon displayed in the tray.
   • Use setToolTip() to set a tooltip that appears when the user hovers over the icon.

4. Show the icon initially (if desired)
   

   trayIcon->show();
   

5. Hide the icon when needed
   

   trayIcon->hide();
   

Complete Example

#include <QtWidgets>

int main(int argc, char* argv[]) {
    QApplication app(argc, argv);

    QSystemTrayIcon* trayIcon = new QSystemTrayIcon(QIcon(":/icon.png"), &app);
    trayIcon->setToolTip("My Application");
    trayIcon->show();

    // ... your application logic ...

    // Hide the icon when necessary
    trayIcon->hide();

    return app.exec();
}

Additional Considerations

• Consider using signals and slots to trigger hiding the icon based on specific events in your application, such as the main window closing.
• To show the icon again after hiding it, use show().
• You can check if the icon is currently visible using visible().

---

#include <QtWidgets>

class MyWindow : public QWidget {
    Q_OBJECT

public:
    MyWindow(QWidget* parent = nullptr) : QWidget(parent) {
        setWindowTitle("My Application");
        setFixedSize(400, 300);

        // Create and configure the tray icon
        trayIcon = new QSystemTrayIcon(QIcon(":/icon.png"), this);
        trayIcon->setToolTip("My Application");
        trayIcon->show();
    }

protected:
    void closeEvent(QCloseEvent* event) override {
        if (trayIcon->isVisible()) {
            // Hide the tray icon before closing the window
            trayIcon->hide();
            event->ignore(); // Prevent immediate window closing
        } else {
            // Allow closing if the tray icon is already hidden
            accept();
        }
    }

private:
    QSystemTrayIcon* trayIcon;
};

int main(int argc, char* argv[]) {
    QApplication app(argc, argv);

    MyWindow window;
    window.show();

    return app.exec();
}

1. • Inherits from QWidget to create a simple window.
   • Creates a QSystemTrayIcon object with an icon and tooltip.
   • Shows the icon initially.

2. closeEvent
   

   • Overrides the closeEvent to handle window closing.
   • Checks if the tray icon is visible using isVisible().
   • If visible, hides the icon with hide() and ignores the close event (event->ignore()) to prevent immediate closing.
   • This allows the application to handle any necessary actions before fully closing (e.g., saving user data).
   • If the tray icon is already hidden, allows closing by calling accept().

Key Points

• Remember to include the necessary header (#include <QtWidgets>) and any icon resources you use (:/icon.png).
• You can adapt this approach to hide the icon based on other events in your application.
• This example demonstrates a common scenario for hiding the tray icon when the main window closes.

---

setVisible(bool)

• You can use it to both hide (setVisible(false)) and show (setVisible(true)) the icon dynamically.
• This function offers the same functionality as hide() but provides more flexibility.

ContextMenu

• Add an action to the menu that triggers hiding the icon when clicked. Connect the action's triggered() signal to a slot that calls setVisible(false).
• Create a context menu for the system tray icon using setContextMenu(QMenu*).

Custom Visibility Logic

• Use isVisible() to check the current visibility and setVisible() to control it based on your conditions.
• This could involve checking application state, user preferences, or system events.
• Implement your own logic for determining when to hide the icon.

Platform-Specific Approaches (Less Common)

• In some cases, Qt might expose platform-specific APIs for interacting with the system tray. However, these are generally less portable and discouraged for cross-platform development.

• Avoid platform-specific approaches unless absolutely necessary to maintain portability across different operating systems.
• For complex visibility logic, implement your own checks using isVisible() and setVisible().
• If you need more control over user interaction or context-based hiding, a context menu action might be suitable.
• For simple hiding and showing, setVisible() is a convenient option.