emacs/lisp/acdw-org.el

;;; acdw-org.el -*- lexical-binding: t; coding: utf-8-unix -*-
;; Author: Various
;; URL: https://tildegit.org/acdw/emacs

;; This file is NOT part of GNU Emacs.

;;; License:
;; Everyone is permitted to do whatever with this software, without
;; limitation.  This software comes without any warranty whatsoever,
;; but with two pieces of advice:
;; - Don't hurt yourself.
;; - Make good choices.

;;; Commentary:
;; This file is for the weird little `org-mode' functions that just take up
;; space in my main init file.  I've tried to give credit where credit is due.

;;; Code:

;;; unpackaged.el: https://github.com/alphapapa/unpackaged.el

;;; ORG-RETURN-DWIM

(defun unpackaged/org-element-descendant-of (type element)
  "Return non-nil if ELEMENT is a descendant of TYPE.
TYPE should be an element type, like `item' or `paragraph'.
ELEMENT should be a list like that returned by
`org-element-context'."
  ;; MAYBE: Use `org-element-lineage'.
  (when-let* ((parent (org-element-property :parent element)))
    (or (eq type (car parent))
	(unpackaged/org-element-descendant-of type parent))))

(defun unpackaged/org-return-dwim (&optional default)
  "A helpful replacement for `org-return'.  With prefix,
call `org-return'.

On headings, move point to position after entry content.  In
lists, insert a new item or end the list, with checkbox if
appropriate.  In tables, insert a new row or end the table."
  ;; Inspired by John Kitchin:
  ;; http://kitchingroup.cheme.cmu.edu/blog/2017/04/09/A-better-return-in-org-mode/
  (interactive "P")
  (if default
      (org-return)
    (cond
      ;; Act depending on context around point.

      ;; NOTE: I prefer RET to not follow links, but by uncommenting
      ;; this block, links will be followed.
      ;; FURTHER NOTE: Ideally, I would follow links unless point
      ;; /appeared/ to be at the end of the line (even if it's still
      ;; inside the link) -- when it would do `org-return'.  That
      ;; would take some /doing/, however.

      ;; ((eq 'link (car (org-element-context)))
      ;;  ;; Link: Open it.
      ;;  (org-open-at-point-global))

      ((org-at-heading-p)
       ;; Heading: Move to position after entry content.  NOTE: This is
       ;; probably the most interesting feature of this function.
       (let ((heading-start (org-entry-beginning-position)))
	 (goto-char (org-entry-end-position))
	 (cond ((and (org-at-heading-p)
		     (= heading-start (org-entry-beginning-position)))
		;; Entry ends on its heading; add newline after
		(end-of-line)
		(insert "\n\n"))
	       (t
		;; Entry ends after its heading; back up
		(forward-line -1)
		(end-of-line)
		(when (org-at-heading-p)
		  ;; At the same heading
		  (forward-line)
		  (insert "\n")
		  (forward-line -1))
		;; FIXME: looking-back is supposed to be called with
		;; more arguments.
		(while (not (looking-back (rx
					   (repeat 3
						   (seq (optional blank)
							"\n")))
					  nil))
		  (insert "\n"))
		(forward-line -1)))))

      ((org-at-item-checkbox-p)
       ;; Checkbox: Insert new item with checkbox.
       (org-insert-todo-heading nil))

      ((org-in-item-p)
       ;; Plain list.  Yes, this gets a little complicated...
       (let ((context (org-element-context)))
	 (if (or (eq 'plain-list (car context))  ; First item in list
		 (and (eq 'item (car context))
		      (not (eq (org-element-property
				:contents-begin context)
			       (org-element-property
				:contents-end context))))
		 ;; Element in list item, e.g. a link
		 (unpackaged/org-element-descendant-of 'item context))
	     ;; Non-empty item: Add new item.
	     (org-insert-item)
	   ;; Empty item: Close the list.
	   ;; TODO: Do this with org functions rather than operating
	   ;; on the text. Can't seem to find the right function.
	   (delete-region (line-beginning-position) (line-end-position))
	   (insert "\n"))))

      ((when (fboundp 'org-inlinetask-in-task-p)
	 (org-inlinetask-in-task-p))
       ;; Inline task: Don't insert a new heading.
       (org-return))

      ((org-at-table-p)
       (cond ((save-excursion
		(beginning-of-line)
		;; See `org-table-next-field'.
		(cl-loop with end = (line-end-position)
		   for cell = (org-element-table-cell-parser)
		   always (equal (org-element-property
				  :contents-begin cell)
				 (org-element-property
				  :contents-end cell))
		   while (re-search-forward "|" end t)))
	      ;; Empty row: end the table.
	      (delete-region (line-beginning-position)
			     (line-end-position))
	      (org-return))
	     (t
	      ;; Non-empty row: call `org-return'.
	      (org-return))))
      (t
       ;; All other cases: call `org-return'.
       (org-return)))))

;;; ORG-FIX-BLANK-LINES ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun unpackaged/org-fix-blank-lines (&optional prefix)
  "Ensure that blank lines exist between headings and
 between headings and their contents.  With prefix, operate on
 whole buffer. Ensures that blank lines exist after each
 headings's drawers."
  (interactive "P")
  (org-map-entries (lambda ()
		     (org-with-wide-buffer
		      ;; `org-map-entries' narrows the buffer, which
		      ;; prevents us from seeing newlines before the
		      ;; current heading, so we do this part widened.
		      (while (not (looking-back "\n\n" nil))
			;; Insert blank lines before heading.
			(insert "\n")))
		     (let ((end (org-entry-end-position)))
		       ;; Insert blank lines before entry content
		       (forward-line)
		       (while (and (org-at-planning-p)
				   (< (point) (point-max)))
			 ;; Skip planning lines
			 (forward-line))
		       (while (re-search-forward
			       org-drawer-regexp end t)
			 ;; Skip drawers. You might think that
			 ;; `org-at-drawer-p' would suffice, but for
			 ;; some reason it doesn't work correctly when
			 ;; operating on hidden text.  This works, taken
			 ;; from `org-agenda-get-some-entry-text'.
			 (re-search-forward "^[ \t]*:END:.*\n?" end t)
			 (goto-char (match-end 0)))
		       (unless (or (= (point) (point-max))
				   (org-at-heading-p)
				   (looking-at-p "\n"))
			 (insert "\n"))))
		   t (if prefix
			 nil
		       'tree)))

(defun acdw/hook--org-mode-fix-blank-lines ()
  (when (eq major-mode 'org-mode)
    (let ((current-prefix-arg 4))
      (call-interactively #'unpackaged/org-fix-blank-lines))))

(provide 'acdw-org)