Speed improvement hack for dired with EWW

I have used EWW in Emacs for some of my browsing for a while and it does the job very well unless browsing single page applications or other sites that do not send HTML unless you run JavaScript. Thank you Lars Magne Ingebrigtsen for making EWW! Hitting R filters out all the noise for a really pleasant reading experience. It is good to browse within Emacs with no context switching in a keyboard-driven way.

(Apropos the joys of context switching: When I am a bit tired, I use Emacs keybindings everywhere. Tap-to-click is naturally off on my laptops to prevent insanity. I am often able to "help" my students a lot within just a few seconds of random keybindings and clicking everywhere on their laptops. It is really good for students to learn patience and tolerance towards people unable to handle computers. They need that for their user support class and future work in the IT industry.)

When Joshua Blaise wrote about his eww setup and use, I read it with interest and stole most of his ideas for my own config. The important one for this little hack is that I set up URLs with endings like .mp3, .mp4, .m4v, .mkv etc to launch in mpv when browsing to them. This makes watching videos and listening to audio content easy with EWW. EWW is also good for browsing local files by hitting W with point on a file in dired.

In dired, I usually launch external programs for photo editing, media playback etc by pressing & with point on a file name. This brings up the completing-read interface in the minibuffer which asks me if I would like to use dired's guess as to which program to use (which I have set to guess xdg-open first) or something else. I press return and then mpv, gimp, darktable or whatever launches with the file.

I had an html file in my downloads folder which I launched with W to read in EWW. I then, by mistake, hit W when on a .mp3 file, and it launched in mpv. Since W launches the file in EWW and EWW was configured to open .mp3 files in mpv, it did that without asking me which program to use. It is faster to hit W than to hit & RET, or in worst case write a program name and RET. So now I launch media files with W in dired in stead of using &. It speeds things up a bit.

(While writing this, I also remembered that I have functions for playing enclosure links and links in elfeed through mpv that I might replace or improve by shuffling the links to EWW or einar-browse-url-mpv. I wrote my configuration for elfeed very early in my Emacs journey, without really understanding any of it, by copying snippets from the Emacs wiki, blogs and Reddit so it is high time to look at it again anyway. I can probably simplify it.)

Here are the relevant parts of my configuration for EWW to get this working:

(defun einar-browse-url-mpv (url &rest _args)
  "Opens URL in mpv."
  (start-process "mpv" nil "mpv" url))

(use-package eww
  :config
  (setopt browse-url-handlers
          '(("\\(youtube\\.com\\|youtu\\.be\\|vimeo\\.com\\|twitch\\.tv\\)" . einar-browse-url-mpv)
            ("\\.mp3$" . einar-browse-url-mpv)
            ("\\.mp4$" . einar-browse-url-mpv)
            ("\\.webp$" . einar-browse-url-mpv)
            ("\\.m4v$" . einar-browse-url-mpv)
            ("\\.mkv$" . einar-browse-url-mpv)
            ("\\.pdf$" . einar-browse-url-pdf)
            ("." . eww-browse-url))))