Syntax Highlighting Outside Your Editor

Whether you’re giving a talk, sharing work with your team, or presenting work to your clients, there comes a time when you’ll need to show code outside of a text editor. Copying and pasting code from a text editor to say, Keynote, is an easy process. The difficulties come in when you want to preserve syntax highlighting, which is crucial to bringing code to life.

I’m in the midst of building a few talks that contain a lot of code, so I’ve been exploring tools to improve my workflow from my editor of choice, Sublime Text, to Keynote. I was looking for the easiest way to copy code as rich text—with my preferred color scheme, font face, and font size applied—to be pasted directly into Keynote.

The first tool I tried was a Sublime Text package, installed with Package Control, called SublimeHighlight. With SublimeHighlight installed, you can select code and trigger a command to copy the code to your clipboard as rich text.

Built on top of Pygments, it’s a really nice package for Sublime Text that fits my workflow perfectly. However, the available format options didn’t feel extensive or powerful, and I seemed to be doing a lot of tweaking in Keynote. The speed of copying directly out of Sublime Text was outweighed by the time I spent in Keynote.

I began looking for a tool that would allow me to spend less time tweaking styles in Keynote, and found Highlight, a command line utility with a terrifying amount of documentation. Fear not; the learning curve is low, and the possibilities are endless. To install it, either follow the instructions, or if you’re running OS X and Homebrew, just run brew install highlight.

To achieve my direct-to-Keynote nirvana, I played with the available command line options a bit until I was satisfied. What I came up with looked like this:

highlight -O rtf -t 2 -K 40 -k 'Source Code Pro' --style twilight _output.js | pbcopy

Though verbose, it’s not as complicated as it looks: -O rtf sets the output format to rich text, -t 2 sets tabs to 2 spaces, -K 40 sets font size to 40, and -k 'Source Code Pro' sets the font face to Source Code Pro, my preferred font face. I created a theme to match my preferred color scheme, Twilight, and specify its use by including --style twilight. To use this without the custom theme, just leave the --style twilight out.

The final bit, _output.js | pbcopy, tells Highlight to run _output.js, the file containing code to be processed, through its formatter and copy the results to the clipboard. All I have to do is run that line, paste into Keynote, and I have a perfectly formatted chunk of code.

It’s not the perfect workflow by any means, but I love the amount of flexibility and control Highlight provides. You can see how I’ve been making heavy use of this tool in talks that I’ve posted to Speaker Deck.