Detecting the removal of a screen and modifying the app accordingly.

MrCrackPotBuilder

So far I have an application that counts how many screens are available.

QDesktopWidget *widget = QApplication::desktop();
qDebug() << 'Number of screens:' << widget->screenCount();

if (widget->screenCount() > 1) {
    leftScreen.show();
    rightScreen.show();
    singleScreen.close();
} else if (widget->screenCount() == 1){
    leftScreen.close();
    rightScreen.close();
    singleScreen.show();
}

This will debug how many screens to console and if more than 1 the 2 screens are shown and if only one then the one screen.

If i remove a screen though nothing else changes but if i close the application and then open it again the single ui will display.

QGuiApplication has a member called screenRemoved but im struggling to figure out how to incorporate that into my application.

Later i will tell each screen to go to its set place but that is pretty straight forward.

sierdzio

You can listen to screenCountChanged() signal to know when the count changes.

MrCrackPotBuilder

Thanks although what arguments do i put in? The docs don't really mention much.

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

mrjj

@MrCrackPotBuilder
Hi
Its a signal so you would connect it up to your own slot and Qt will then call
this slot when screen count changes.

MrCrackPotBuilder

ah then im going to need to make a new header and source file becuase its all being done in main.cpp

im taking a wild guess but inside my main i could do

QQuiApplicationt::connect(&screenRemoved, &displayChange::displayChange);

J.Hilk

@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);