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.
void setCurrentWalletBySelectorIndex(int index);
    /** Set the UI status indicators based on the currently selected wallet.
    */
    void updateWalletStatus();
private:
    /** Set the encryption status as shown in the UI.
       @param[in] status            current encryption status
       @see WalletModel::EncryptionStatus
    */
    void setEncryptionStatus(int status);
    /** Set the hd-enabled status as shown in the UI.
     @param[in] hdEnabled         current hd enabled status
     @see WalletModel::EncryptionStatus
     */
    void setHDStatus(bool privkeyDisabled, int hdEnabled);
public Q_SLOTS:
    bool handlePaymentRequest(const SendCoinsRecipient& recipient);
    
    void incomingTransaction(const QString& date, int unit, const CAmount& amount, const QString& type, const QString& address, const QString& label, const QString& walletName);
#endif 
private:
    
    void updateProxyIcon();
    void updateWindowTitle();
public Q_SLOTS:
#ifdef ENABLE_WALLET
    
    void gotoOverviewPage();
    
    void gotoHistoryPage();