@MrCrackPotBuilder said in Detecting the removal of a screen and modifying the app accordingly.:

Its also saying the same as before so I.m definitely going to have to use the QGuiApplication but how that i cant figure out... Yet

you #include <QGuiApplication> in your class that than allows you access to the (unique) application instance pointer qApp than you can use that to update your Layout.

QObject::connect(qApp, &QGuiApplication::screenCountChanged, this, &myClass::screenCountSlot);

@SGaist yes but i removed it because now i am facing a new problem and here its.

Yes i did.

And with that clue i figured it out! QApplication::desktop()->screenGeometry(screenIndex); works like a charm.
Tyvm!

You're welcome,

the good thing is that it's easy to mix Objective-C code and C++ Qt