PDF multi view

While playing with Rust on μCs I’ve always at least one date sheet or reference manual open. These pdf files, especially the reference manuals, are huge (> 1k pages) and consume a fair amount of RAM when opened in a viewer like evince or zathura. I found myself struggling to navigate between different parts of the manual with a pretty high frequency. Take a look at some transfer sequence diagram, check the description of the control register, go back to the diagram, …

What I needed was a way to view at least two different parts of the same pdf file at the same time. Turns out no pdf viewer known to me was able to split the view into multiple views on the same document. Opening the file two times works, but eats the RAM.

Someone suggested to implement it as some kind of plugin for Atom. Nahhh never, if I had that much RAM to waste I would just open the file several times ;-) But wait, Atom is an editor, I use an editor, I use Emacs, I bet Emacs can do this.

And indeed Emacs would open the pdf file using DocView mode and handle it like a normal buffer, which means I can open many windows and just point them at different parts of the buffer. Cool but not optimal since I had no way to recolor the pdf and don’t go blind reading these at night (or day, doesn’t really matter for me). There is an alternative mode to work with pdf files: pdf-tools. And it’s quite awesome. Using its midnight mode and customizing some colors I was back to where I left zathura.

(custom-set-variables
    '(pdf-view-midnight-colors (quote ("#f2be0f" . "#1a1a1a"))))

There is even a spacemacs layer you can enable by adding pdf-tools to your dotspacemacs-configuration-layers.

And there I am wondering why I left Emacs to view pdf files in the first place. Stupid me.