Configure QSettings ((QSettings::Format and QSettings::Scope )

[hbatalha]

I use QSettings in many places in my application so I want to use:

QCoreApplication::setOrganizationName("MySoft"); 
QCoreApplication::setOrganizationDomain("mysoft.com"); 
QCoreApplication::setApplicationName("Star Runner");

And then only use QSettings settings. But if I call the default constructor the default QSettings::Format and QSettings::Scope used is not what I want.

I want to know if I can set QSettings::Format and QSettings::Scope just like I set the Organization Name beforehand?

[Chris Kawa]

@hbatalha QSettings has static setDefaultFormat that you can call along those other set* functions, so the only part missing is the default scope, but it's not so bad I think?

QSettings settings(QSettings::SystemScope);

It does feel like it would be kinda completing the API nicely if there was also something like static QSettings::setDefaultScope(QSettings::Scope). You could file a feature request on bugreports.qt.io if that's something you'd like to see in future versions.

[jsulm]

@hbatalha said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

QCoreApplication::setOrganizationName("MySoft");
QCoreApplication::setOrganizationDomain("mysoft.com");
QCoreApplication::setApplicationName("Star Runner");

Where exactly in your code do you execute this?

[hbatalha]

@jsulm said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

Where exactly in your code do you execute this?

in the main.cpp

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

    QCoreApplication::setOrganizationName("MySoft");
    QCoreApplication::setOrganizationDomain("mysoft.com");
    QCoreApplication::setApplicationName("Star Runner");

...

[VRonin]

Just subclass QSettings

class MySettings : public QSettings{
    Q_OBJECT
    Q_DISABLE_COPY(MySettings)
public:
    explicit MySettings(QObject *parent = nullptr)
        : QSettings(QSettings::IniFormat, QSettings::UserScope, 
#ifdef Q_OS_DARWIN
            QStringLiteral("mysoft.com")
#else
            QStringLiteral("MySoft")
#endif
            , QStringLiteral("Star Runner"), parent)
    {}
};

now use MySettings settings wherever you'd have used QSettings settings

[kshegunov]

@VRonin said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

Just subclass QSettings

Ugh!
Can't we have something like this instead?*

QSettings mySettings()
{
    return QSettings(QSettings::IniFormat, QSettings::UserScope, QStringLiteral(...));
}

*c++17 and later

Use directly on initialization:

QSettings settings = mySettings();

[VRonin]

@kshegunov said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

Can't we have something like this instead?*

Potato/Potatoe

[kshegunov]

@VRonin said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

Potato/Potatoe

The point is to avoid type proliferation, I know you know that's a thing. Why derive anything if you don't have to; you're not changing any behavior here!

[J.Hilk]

@kshegunov don't you still need a class for this, or do you advocate a global free floating function here?

[kshegunov]

@J-Hilk said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

@kshegunov don't you still need a class for this, or do you advocate a global free floating function here?

A normal C-like function, inline-d ideally. Why would you make a class for this?

[SGaist]

@kshegunov you can't as QSettings is a QObject.

It does work with C++17, see @kshegunov answer below.

[Chris Kawa]

@hbatalha QSettings has static setDefaultFormat that you can call along those other set* functions, so the only part missing is the default scope, but it's not so bad I think?

QSettings settings(QSettings::SystemScope);

It does feel like it would be kinda completing the API nicely if there was also something like static QSettings::setDefaultScope(QSettings::Scope). You could file a feature request on bugreports.qt.io if that's something you'd like to see in future versions.

[kshegunov]

@SGaist said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

@kshegunov you can't as QSettings is a QObject.

Au contraire mon ami! Excuse the bad friench, but the point is C++17 mandates RVO, so this compiles and runs correctly with g++. You don't make no copies here.

[SGaist]

The French part is completely correct :-)
I missed the C++17 bits. My bad !

[kshegunov]

@SGaist said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

The French part is completely correct :-)

Good that my initial (and rather inexcusable) error was caught on time ;)

[hbatalha]

@Chris-Kawa said in Configure QSettings ((QSettings::Format and QSettings::Scope ):

QSettings has static setDefaultFormat that you can call along those other set* functions, so the only part missing is the default scope, but it's not so bad I think?

That's a good idea, I read it in the doc but misunderstood its role. I will try this approach and @kshegunov's answer and get back to you.