Org-mode Source Block Visibility Cycling - emacs

Question

I'm trying to add source blocks to the visibility cycling tree. Essentially I want a source block to be treated as a child of its heading. Consider the following org-mode document:
* Heading 1
** Heading 2
#+BEGIN_SRC R
print("hello world")
#+END_SRC
** Heading 3
I would like to be able to press TAB on heading one to cycle through the folding of the various parts including the source block. Currently org-mode does seem to have the facilities for folding the source block, because I can fold that if I go to #+BEGIN_SRC R and hit tab, but it doesnt seem to be being treated in the global cycling. Any suggestions to add it?
Thanks!

Answer 1

This is a slight modification of the code contained in the link mentioned in my first comment above: https://stackoverflow.com/a/21594242/2112489
All I did was replace the begin / end html regexp for the SRC regexp. Go ahead and give it a whirl and see if it is what you're looking for. I left my prior footnote modification in there.
(require 'org)
(defalias 'org-cycle-hide-drawers 'lawlist-block-org-cycle-hide-drawers)
(defun lawlist-block-org-cycle-hide-drawers (state)
"Re-hide all drawers, footnotes or html blocks after a visibility state change."
(when
(and
(derived-mode-p 'org-mode)
(not (memq state '(overview folded contents))))
(save-excursion
(let* (
(globalp (memq state '(contents all)))
(beg (if globalp (point-min) (point)))
(end
(cond
(globalp
(point-max))
((eq state 'children)
(save-excursion (outline-next-heading) (point)))
(t (org-end-of-subtree t)) )))
(goto-char beg)
(while
(re-search-forward
".*\\[fn\\|^\\#\\+BEGIN_SRC.*$\\|^[ \t]*:PROPERTIES:[ \t]*$" end t)
(lawlist-org-flag t))))))
(defalias 'org-cycle-internal-local 'lawlist-block-org-cycle-internal-local)
(defun lawlist-block-org-cycle-internal-local ()
"Do the local cycling action."
(let ((goal-column 0) eoh eol eos has-children children-skipped struct)
(save-excursion
(if (org-at-item-p)
(progn
(beginning-of-line)
(setq struct (org-list-struct))
(setq eoh (point-at-eol))
(setq eos (org-list-get-item-end-before-blank (point) struct))
(setq has-children (org-list-has-child-p (point) struct)))
(org-back-to-heading)
(setq eoh (save-excursion (outline-end-of-heading) (point)))
(setq eos (save-excursion (1- (org-end-of-subtree t t))))
(setq has-children
(or
(save-excursion
(let ((level (funcall outline-level)))
(outline-next-heading)
(and
(org-at-heading-p t)
(> (funcall outline-level) level))))
(save-excursion
(org-list-search-forward (org-item-beginning-re) eos t)))))
(beginning-of-line 2)
(if (featurep 'xemacs)
(while
(and
(not (eobp))
(get-char-property (1- (point)) 'invisible))
(beginning-of-line 2))
(while
(and
(not (eobp))
(get-char-property (1- (point)) 'invisible))
(goto-char (next-single-char-property-change (point) 'invisible))
(and
(eolp)
(beginning-of-line 2))))
(setq eol (point)))
(cond
((= eos eoh)
(unless (org-before-first-heading-p)
(run-hook-with-args 'org-pre-cycle-hook 'empty))
(org-unlogged-message "EMPTY ENTRY")
(setq org-cycle-subtree-status nil)
(save-excursion
(goto-char eos)
(outline-next-heading)
(if (outline-invisible-p)
(org-flag-heading nil))))
((and
(or
(>= eol eos)
(not (string-match "\\S-" (buffer-substring eol eos))))
(or
has-children
(not (setq children-skipped
org-cycle-skip-children-state-if-no-children))))
(unless (org-before-first-heading-p)
(run-hook-with-args 'org-pre-cycle-hook 'children))
(if (org-at-item-p)
;; then
(org-list-set-item-visibility (point-at-bol) struct 'children)
;; else
(org-show-entry)
(org-with-limited-levels (show-children))
(when (eq org-cycle-include-plain-lists 'integrate)
(save-excursion
(org-back-to-heading)
(while (org-list-search-forward (org-item-beginning-re) eos t)
(beginning-of-line 1)
(let* (
(struct (org-list-struct))
(prevs (org-list-prevs-alist struct))
(end (org-list-get-bottom-point struct)))
(mapc (lambda (e) (org-list-set-item-visibility e struct 'folded))
(org-list-get-all-items (point) struct prevs))
(goto-char (if (< end eos) end eos)))))))
(org-unlogged-message "CHILDREN")
(save-excursion
(goto-char eos)
(outline-next-heading)
(if (outline-invisible-p)
(org-flag-heading nil)))
(setq org-cycle-subtree-status 'children)
(unless (org-before-first-heading-p)
(run-hook-with-args 'org-cycle-hook 'children)))
((or
children-skipped
(and
(eq last-command this-command)
(eq org-cycle-subtree-status 'children)))
(unless (org-before-first-heading-p)
(run-hook-with-args 'org-pre-cycle-hook 'subtree))
(outline-flag-region eoh eos nil)
(org-unlogged-message
(if children-skipped
"SUBTREE (NO CHILDREN)"
"SUBTREE"))
(setq org-cycle-subtree-status 'subtree)
(unless (org-before-first-heading-p)
(run-hook-with-args 'org-cycle-hook 'subtree)))
((eq org-cycle-subtree-status 'subtree)
(org-show-subtree)
(message "ALL")
(setq org-cycle-subtree-status 'all))
(t
(run-hook-with-args 'org-pre-cycle-hook 'folded)
(outline-flag-region eoh eos t)
(org-unlogged-message "FOLDED")
(setq org-cycle-subtree-status 'folded)
(unless (org-before-first-heading-p)
(run-hook-with-args 'org-cycle-hook 'folded))))))
(defun lawlist-org-flag (flag)
"When FLAG is non-nil, hide any of the following: html code block;
footnote; or, the properties drawer. Otherwise make it visible."
(save-excursion
(beginning-of-line 1)
(cond
((looking-at ".*\\[fn")
(let* (
(begin (match-end 0))
end-footnote)
(if (re-search-forward "\\]"
(save-excursion (outline-next-heading) (point)) t)
(progn
(setq end-footnote (point))
(outline-flag-region begin end-footnote flag))
(user-error "Error beginning at point %s." begin))))
((looking-at "^\\#\\+BEGIN_SRC.*$\\|^[ \t]*:PROPERTIES:[ \t]*$")
(let* ((begin (match-end 0)))
(if (re-search-forward "^\\#\\+END_SRC.*$\\|^[ \t]*:END:"
(save-excursion (outline-next-heading) (point)) t)
(outline-flag-region begin (point-at-eol) flag)
(user-error "Error beginning at point %s." begin)))))))
(defun lawlist-toggle-block-visibility ()
"For this function to work, the cursor must be on the same line as the regexp."
(interactive)
(if
(save-excursion
(beginning-of-line 1)
(looking-at
".*\\[fn\\|^\\#\\+BEGIN_SRC.*$\\|^[ \t]*:PROPERTIES:[ \t]*$"))
(lawlist-org-flag (not (get-char-property (match-end 0) 'invisible)))
(message "Sorry, you are not on a line containing the beginning regexp.")))