Operate PhotoBooth with mouse clicks I would like to make a wedding photo booth using my macbookpro and the osx photo booth software. To prevent that the guest can click away the apps or do things that I don't want to, I build the laptop into a box so the keyboard and trackpad are covered. I connected an old USB mouse with 2 switches soldered to the left and right buttons and I want the left button to activate the shutter and the other button change the build in effects. 

Is there anybody who can point me in the right direction?

Thanks in advance!
The problem with your solution is that as far as I know PhotoBooth doesn't have a "next effect" command. One must click the "effects" button and choose. What you could do is create a new empty user, so people won't access your personal stuff, and lock the computer with PhotoBooth using a script.

Follow these steps, changing the application from Finder to PhotoBooth:
https://apple.stackexchange.com/a/337191/197509

People won't be able to do other stuff unless they can reach the keyboard.