Pretty Org babel blocks
I show how to use
prettify-symbols-mode to display Org Babel blocks as
something like this:
where “☰” expands to the header arguments of the block as shown in the picture.
I have been using Org and Babel to create “interactive” slides. A slide is a narrowed subtree. To not confuse listeners I want to hide the details of the rather verbose source block syntax.
I tried to hack something together with
even getting the compositing right I was still missing the
“uncomposition” behavior of
prettify-symbols-unprettify-at-point is non-nil (I like
prettify-symbols-alist only supports strings, not
regexps as it uses
regexp-opt behind the scene.
Thus, I decided to just hack something together with
prettify-symbols-mode. rasmus/org-prettify-src–update goes through
the buffer and add all occurrences of header arguments to
prettify-symbols-alist and also removes old chun. This is probably
not very efficient… Next, rasmus/org-prettify-src takes care of
calling the update function whenever the cursor was in a
before and now is not. Finally, rasmus/org-prettify-symbols is a hook
that can be added to Org.
If you don’t want to use the burger icon you can change it by changing rasmus/ob-header-symbol.
This is clearly a hack! Some obvious flaws are:
prettify-symbols-modedoesn’t support regexp you can’t fully match the proper Org syntax. E.g. this is not valid syntax, but would still be prettified.
- It might be nice to reveal the burger whenever the cursor is on the same line as the burger. I tried to get this working, but I couldn’t get it working property.
- It would be nice to turn it into a proper minor-mode to easily toggle fortification of header arguments…
(defvar-local rasmus/org-at-src-begin -1
"Variable that holds whether last position was a ")
(defvar rasmus/ob-header-symbol ?☰
"Symbol used for babel headers")
(defun rasmus/org-prettify-src--update ()
(let ((case-fold-search t)
(re "^[ \t]*#\\+begin_src[ \t]+[^ \f\t\n\r\v]+[ \t]*")
(while (re-search-forward re nil t)
(goto-char (match-end 0))
(let ((args (org-trim
(when (org-string-nw-p args)
(let ((new-cell (cons args rasmus/ob-header-symbol)))
(cl-pushnew new-cell prettify-symbols-alist :test #'equal)
(cl-pushnew new-cell found :test #'equal)))))
(eq (cdr elm) rasmus/ob-header-symbol))
found :test #'equal)))
;; Clean up old font-lock-keywords.
(font-lock-remove-keywords nil prettify-symbols--keywords)
(setq prettify-symbols--keywords (prettify-symbols--make-keywords))
(font-lock-add-keywords nil prettify-symbols--keywords)
(while (re-search-forward re nil t)
(font-lock-flush (line-beginning-position) (line-end-position))))))
(defun rasmus/org-prettify-src ()
"Hide src options via `prettify-symbols-mode'.
`prettify-symbols-mode' is used because it has uncollpasing. It's
may not be efficient."
(let* ((case-fold-search t)
(looking-at "^[ \t]*#\\+begin_src[ \t]+[^ \f\t\n\r\v]+[ \t]*"))))
;; Test if we moved out of a block.
(when (or (and rasmus/org-at-src-begin
;; File was just opened.
(eq rasmus/org-at-src-begin -1))
;; Remove composition if at line; doesn't work properly.
;; (when at-src-block
;; (remove-text-properties (match-end 0)
;; (1+ (line-end-position))
(setq rasmus/org-at-src-begin at-src-block)))
(defun rasmus/org-prettify-symbols ()
(mapc (apply-partially 'add-to-list 'prettify-symbols-alist)
(mapcar (lambda (x) (list x (cons (upcase (car x)) (cdr x))))
`(("#+begin_src" . ?✎) ;; ➤ 🖝 ➟ ➤ ✎
("#+end_src" . ?□) ;; ⏹
("#+header:" . ,rasmus/ob-header-symbol)
("#+begin_quote" . ?»)
("#+end_quote" . ?«)))))
(add-hook 'post-command-hook 'rasmus/org-prettify-src t t))
(add-hook 'org-mode-hook #'rasmus/org-prettify-symbols))