Show window in Qt without stealing focus

Question

I\'m using the Qt library to show a slideshow on the second monitor when the user isn\'t using the second monitor. An example is the user playing a game in the first monitor

Answer 1

Widgets don't accept focus by default but presumably you haven't created a plain widget? Which subclass was it? QMainWindow or something else?

It's possible the window subclasses default to accepting focus so try explicitly calling QWidget::setFocusPolicy with Qt::NoFocus before calling QWidget::show().

Also, make sure you're not calling QWidget::activateWindow() on the window or any of its widgets at any point.

Answer 2

It took me a while to find it but I found it: setAttribute(Qt::WA_ShowWithoutActivating);

This forces the window not to activate. Even with the Qt::WindowStaysOnTopHint flag

Answer 3

If you want to make floating preview box/ any other widget just use below

thumbnail = new QLabel;
thumbnail->setAttribute(Qt::WA_ShowWithoutActivating);
thumbnail->setParent(0);
thumbnail->setWindowFlags(Qt::Tool | Qt::FramelessWindowHint|Qt::WindowStaysOnTopHint);

Qt::Tool is important flag to make it work. I mean not stealing focus.