Emergency messaging buttons on a pc

Hi Is there a way of having emergency messaging buttons on a pc desktop that will deploy to all the screens , like for example evacuate.

Technically yes, assuming you’re using 1.8 series CMS and players.

You could write a script that would use Xibo API, triggered by the press of a button.
You would need to create a special layout for the occasion - even just with text widget and the message you want to show.
The script would send a changeLayout call to ALL displays (thanks to XMR it should be pushed to the player immediately).

Similar could be achieved with the overlayLayout action.

You could also have a special layout with notification widget in it, then in the script you’d add a new notification to the specified displays (or all of them) and then issue changeLayout with that layout to specified displays (or all of them).