Using master (98958c81f5065a5de13699d46995d278ecb6709e) with Qt `5.12.3` (also tested with depends) with multiple wallets available. None are shown in the `Open Wallet ->` menu in the gui. The wallets can be loaded from the console, bitcoin-cli etc.
{
    Q_OBJECT
public:
    explicit UnitDisplayStatusBarControl(const PlatformStyle *platformStyle);
    
    void setOptionsModel(OptionsModel *optionsModel);
protected:
    
    void mousePressEvent(QMouseEvent *event);
private:
    OptionsModel *optionsModel;
    QMenu* menu;
    
    void onDisplayUnitsClicked(const QPoint& point);
    
    void createContextMenu();
private Q_SLOTS:
    
    void updateDisplayUnit(int newUnits);
    
    void onMenuSelection(QAction* action);
};
#endif