If some changes happen to the screen, hot-plugging, removal, or resolution change, then you can receive the notification.
One way is to use
configure-notify-hook.(see X Hooks)
Then the window argument is set to the symbol
root. The other way
is to use
randr-change-notify-hook below. Both are called,
but there’s no guarantee of the order.
Notice that both may be called several times for one change. For example, “xrandr” command invocation from shell triggers three calls of both hooks in an author’s environment.
Called when screen configuration changes, via RandR extension support. When RandR is not supported, then this hook will never be called.