How to check if the application has been minimized

[summit]

int main(int argc, char *argv[])
{
    QApplication application(argc, argv);
    Renderer w(model ); // This is  QWidget
    w.show();
    QObject::connect(&w, &QWindow::windowStateChanged, [&](Qt::WindowState state) {
        });

        // how will i define the QObject::connect 
    return application.exec();
}

What would be the parameters for the QObject::connect function ?

[jsulm]

@summit said in How to check if the application has been minimized:

What would be the parameters for the QObject::connect function ?

You already have the connect, so what is the question?
Just check state == Qt::WindowMinimized in your lambda...

[summit]

@jsulm No this does not connect it gives an error during compile time , no instance of overloaded function matches the argument list.

so i try this

QWindow *wndQT = (QWindow*)w.window();
		QObject::connect(wndQT, &QWindow::windowStateChanged , [&](Qt::WindowState state) {
			qDebug() << "Minimized";
		});

This is able to compile but the lambda is never executed.

[jsulm]

@summit w.window() returns a QWidget, not QWindow.
Try

QObject::connect(QApplication::activeWindow(), &QWindow::windowStateChanged , [&](Qt::WindowState state) {
			qDebug() << "Minimized";
		});

[summit]

@jsulm This does not compile as QApplication::activeWindow() also returns QWidget*

i have to cast it to compile.

QObject::connect((QWindow*)QApplication::activeWindow(), &QWindow::windowStateChanged , [&](Qt::WindowState state) {
qDebug() << "Minimized";
});

But still lambda does not execute.

[summit]

Using QApplication::focusWindow() i was able to get the window.

QObject::connect(QApplication::focusWindow(), &QWindow::windowStateChanged , [&](Qt::WindowState state) {
qDebug() << "Minimized";
});

[JonB]

@summit
Just for the record, you do actually need/ought check the value of the state parameter to the lambda:

if (state == Qt::WindowMinimized) qDebug() << "Minimized";

?

[summit]

@JonB Yes i am doing that.