using QString as argmuent in SLOT macro

Question

Is it possible to be used as an argument QString in SLOT macro? PS. I mean a simple solution .. Not as in QMetaObject::connectSlotsByName().

Answer 1

No you cannot pass QString to SLOT macro. But you can use QString for connect. Also connect cannot take QString, so you have to convert it to const char *. Simple example is:

QString slotName = SLOT(clicked());
connect(ui->pushButton, SIGNAL(clicked()), qPrintable(slotName));

SLOT just stringifies passed parameter and concatenate it with 1:

# define SLOT(a)     qFlagLocation("1"#a QLOCATION)

If you don't want to use SLOT it's possible to write code like this:

QString slotName = QString::number(QSLOT_CODE) + "clicked()";

Answer 2

This is raw code from my current project. It parses chat commands like /me customtext and calls cmd_me( const QString& params ); slot. To introduce new command it's enough to create private slot with void cmd_*( const QString& ); signature.

Here is code:

void ConsoleController::onCommand( const QString& cmd )
    {
        if ( cmd.length() < 1 )
            return ;
        if ( cmd[0] != '/' )
            return ;

        const QMetaObject *meta = metaObject();

        int posParam = cmd.indexOf( ' ' );
        if ( posParam == -1 )
            posParam = cmd.length();
        const QString command = cmd.mid( 1, posParam - 1 ).toLower();
        const QString params = cmd.mid( posParam + 1 );
        const QString slotName = QString( "cmd_%1( const QString& )" ).arg( command );
        const QString normalizedSlotName = QMetaObject::normalizedSignature( slotName.toStdString().c_str() );

        for ( int i = 0; i < meta->methodCount(); i++ )
        {
            QMetaMethod method = meta->method( i );
            if ( method.methodType() != QMetaMethod::Slot )
                continue;

            const QString signature = method.signature();
            if ( normalizedSlotName == signature )
            {
                method.invoke( this, Q_ARG( QString, params ) );
                return ;
            }
        }

        log( QString( "Command \"%1\" not recognized, type /help to list all available commands" ).arg( command ) );
    }

You can take an idea and adapt it for your needs.