Hello,
I created the attached code to be able to preview SVG in org mode. Please
comment if you have suggestions for a better approach.
It works by having svg in a #+begin_src svg block and running org-format-svg on
it.
I took inspiration from org-format-latex and wonder whether it should be merged
with that function.
Upsides:
- The same keybinding (C-c C-x C-l) could be used.
- Less duplicated code
- More?
Downsides:
- The name of the function would be misleading
- Other breakage
- More?
It could also be integrated with the C-c mechanisms on src_blocks. But I don’t
know how to do that.
Best regards
Robert
(defun org--make-svg-preview-overlay (beg end image)
"Build an overlay between BEG and END using the svg image data."
(let ((ov (make-overlay beg end)))
(overlay-put ov 'org-overlay-type 'org-svg-overlay)
(overlay-put ov 'evaporate t)
(overlay-put ov
'modification-hooks
(list (lambda (o _flag _beg _end &optional _l)
(delete-overlay o))))
(overlay-put ov
'display
(find-image `((:type svg :data ,image :scale 1
:transform-smoothing t))))))
(defun org-format-svg (&optional beg end)
(let ((context-regexp "#\\+begin_src +svg"))
(goto-char (or beg (point-min)))
(while (re-search-forward context-regexp end t)
(let* ((context (org-element-context))
(type (org-element-type context)))
(when (and (eq type 'src-block)
(string= (org-element-property :language context) "svg"))
(let* ((value (org-element-property :value context))
(beg (org-element-property :begin context))
(end (save-excursion
(goto-char (org-element-property :end context))
(skip-chars-backward " \r\t\n")
(point))))
(progn
(dolist (o (overlays-in beg end))
(when (eq (overlay-get o 'org-overlay-type) 'org-svg-overlay)
(delete-overlay o))))
(org--make-svg-preview-overlay beg end value)
(goto-char end)))))))
(defun org-clear-svg-preview (&optional beg end)
(let ((overlays (cl-remove-if-not
(lambda (o) (eq (overlay-get o 'org-overlay-type)
'org-svg-overlay))
(overlays-in (or beg (point-min)) (or end (point-max))))))
(mapc #'delete-overlay overlays)
overlays))
(defun org-svg-preview (&optional arg)
"Toggle the preview of the svg fragment at point"
(interactive)
(cond
((not (display-graphic-p)) nil) ;; noop on non-graphic displays
((use-region-p)
(org-format-svg (region-beginning) (region-end)))
((let ((context (org-element-context)))
(and (eq (org-element-type context) 'src-block)
(string= (org-element-property :language context) "svg")
(let ((beg (org-element-property :begin context))
(end (org-element-property :end context)))
(if (org-clear-svg-preview beg end)
(message "SVG preview removed")
(message "Creating SVG preview...")
(org-format-svg beg end)
(message "Creating SVG preview... done."))
t))))))
(provide 'bob-org-svg)
