Qt5-compliant implementation of is_gui_app()

[aclex]

Avoid using of obsolete (since Qt5) members of QApplication used to check if we are GUI application. Use dynamic_cast to QGuiApplication instead, which could be a little slower, but seems to be the recommended way.

Turned out to be important for KF5-porting of Kopete, which uses internal copy of libiris.

[Ri0n]

I believe it should be qobject_cast<QApplication *>(QCoreApplication::instance()) Isn't it?

[aclex]

Agreed on qobject_cast, but as to casting to QApplication it seems a little tricky: according to the docs, QApplication implies QWidget-based GUI application, so e.g. for QML-based one it would answer false this way. Unfortunately, I don't know the context for this method, so it's hard to say, what behaviour is desired.

[Ri0n]

Well Ok, let it be QGui* My example was copied from commit deprecating type().

[aclex]

Ok, I seem to have consulted the same commit :) Could you please fix it while merging or should I update the request somehow?

[Ri0n]

Please update the request. You can rewrite history and force push so it still will be just one commit.

[aclex]

Thank you for the suggestion, just updated it this way.

[aclex]

Thank you very much for the merge!

[tehnick]

You have dropped Qt 4.x support due to using of QGuiApplication here.

[aclex]

Oh yes, indeed, that was completely slipped my mind. QApplication, as Ri0n proposed, would be the optimal then. Do we have any chance to rewrite it again?

[Ri0n]

new pool request then. I didn't notice this too =)

[Ri0n]

I'd add few ifdefs

[aclex]

Yeah, just done this way: https://github.com/psi-im/iris/pull/40