Bootstrap Three State Switch

I'm using bootstrap 2.3.2 with bootstrap switch. Two state switch works well, but now I need a three state switch (true, null, false). Is it possible, using bootstrap switch, to make something like this? Maybe using radio buttons instead of a checkbox... I'm using angularJS too so I'll need I directive.

This certainly is possible to create a UI component that can toggle between 3 states, it is just a matter of deciding how you want the UI to look/feel/act.

  1. I would start off by creating a directive that handles a click event that toggles through the states as you click (named something like threeStateBool)
  2. Initially it would just show the strings true false and null to prove that it works
  3. Then decide how you want it to look, the first thought that came to mind would be to use font awesome's ability to stack icons (link) to create the 3 states