Qt menu popups grab keyboard and pointer, preventing user from using system hotkeys (e.g. doing a screenshot)

In Qt applications under X11, menus grab the pointer and keyboard when being popupped. This creates some inconvenience: user can't make a screenshot or use other system hotkeys while the popup is opened. Also, if application hangs in such state, the whole X11 display gets blocked until the application is killed and the grabs are released.

The suggestion is to implement menu popups in a way which doesn't involve grabbing. This would resolve all described (and other similar) issues.