How do I map "caplock to escape but shift+caplock = normal caplock", like Gnome has?

I use i3wm, and to map cap lock to escape, I run:

setxkbmap -option caps:swapescape

This works fine, but sometimes while hitting the F1 key, my pinky can accidentally hit the Escape key, which turns on CapsLock.

Gnome has a very nice way to do this, where Shift + Escape = CapsLock. Hitting Escape on its own will do nothing.