User Active On WebUI Automation Trigger?

Is there an automation trigger or condition that fires only when a user is in the Web/App UI?

I have an event I only want to call when a user is actively on home assistant. The event takes a screenshot and displays it as a camera image. I don’t want to call it if no one will see it!

edit: I can just click the picture and make the default action call the event to update the screen shot. That should work fine if no better solution