QSerialPortInfo isValid() and isBusy()

Question

QSerialPortInfo class has const methods isValid() (deprecated since 5.2) and isBusy() (deprecated since 5.6). They both seem to work but QT documentation does not provide with info whether they should be replaced with isNull() or state of QSerialPortInfo object should be checked some other way.

Can anyone please tell me actual way to check serial port availability?

Answer 1

With reference to the documentation, both isValid() and isBusy() are obsolete and not recommended to be used in new code.

Quote from documentation (emphasis mine):

They are provided to keep old source code working. We strongly advise against using them in new code.

The See also section points to isNull() method so it should be used.

See commit.

Answer 2

I am using the same function call and it appears to work, so I was wondering why the function is obsolete. Turns out, the function opens the port in question, see bug report here. This side effect seems to be the reason why it was marked obsolete and deprecated.

If that side effect is okay with you (and the reported "other issues" by the maintainer in the bug report), then that appears to be an okay way to get done what you're asking for.