Fontify done checkbox items in org-mode

My computer crashed over the weekend and during the re-installation I started migrating my install scripts to puppet (I had roughly 60% covered by puppet prior to that already), so I made a check list in org with all the things to not forget to include. The list grew quite large and hard to process visually.

There is a somewhat nice feature of org mode which you can turn on using org-fontify-done-headline flag; if set to t, DONE headlines will be highlighted in org-headline-done face. I let this face inherit from shadow which effectively removes these lines from my attention.

So to solve my problem naturally I would like to extend this behaviour to checkbox lists. I don't always do them in sequence and so the gradual change from "normal" to "hidden" lines nicely illustrates the progress and makes the todo items stand out.

Just throw the following somewhere and reload the org buffers (close and reopen or toggle fundamental-mode then org-mode again).

(font-lock-add-keywords
 'org-mode
 `(("^[ \t]*\\(?:[-+*]\\|[0-9]+[).]\\)[ \t]+\\(\\(?:\\[@\\(?:start:\\)?[0-9]+\\][ \t]*\\)?\\[\\(?:X\\|\\([0-9]+\\)/\\2\\)\\][^\n]*\n\\)" 1 'org-headline-done prepend))
 'append)

Here's how it looks (list shortened for clarity):

*** TODO Puppet
    :CLOCK:
    CLOCK: [2017-05-21 Sun 18:00]--[2017-05-21 Sun 21:55] =>  3:55
    :END:
- [ ] cli :: Add youtube-dl
- [ ] org :: Add plantuml.jar
- [X] emacs :: Add Cask
- [ ] haskell :: Add Cabal sandbox support and build everything in sandboxes
- [ ] php :: Add Composer
- [ ] emacs :: Add EVM
- [ ] ruby :: Add RVM
- [ ] node :: Add NVM
- [ ] node :: Add NPM
- [X] linux :: Add Wine + Winetricks
- [ ] latin :: Add whitakers-words
- [ ] puppet :: Add support to install "docker" apps
- [X] setup :: Ensure download-local directory
- [ ] prog :: Install global (6.5 at least)
- [ ] linux :: Install pasystray (git)
- [ ] prog :: Install ag (0.31.0+)
- [X] cli :: Install tmux (2.0+)
- [ ] linux :: Install twmn
- [X] desktop :: Install slack (from .deb)
- [ ] cli :: Install fisher
- [X] cli ::Install ledger (from package + elisp mode from source?)
- [ ] mail :: Install isync

(Also note that the above is not a screenshot, it is an embedded org-mode snippet in org-mode's #+BEG_SRC block. Inception.)

I stole the regexp from hlissner's emacs.d who apparently came to the same conclusion. It's a rather nice collection of stuff so check it out, but be warned, it is super idiosyncratic… which in Emacs translation basically means awesome :)