Add postprocessor for refilling previews

Readme.org

@@ -59,6 +59,9 @@ Provides a structured way to use org-roam for representing multiple
 clients/employers. It provides a simple clocking interface built on org-clock
 and provides integrations with org-capture.
 
+** SPIKE [[file:lisp/org-roam-refill-previews.el][org-roam-refill-previews]] /(spike)/
+Refill previews in the backlinks buffer so they fit the window.
+
 * Installation
 Most packages should be manually installable via =package.el=, assuming you have
 [[https://melpa.org/#/getting-started][MELPA]] set up. But honestly, you're better off just cloning this repo and putting

lisp/org-roam-refill-previews.el

@@ -0,0 +1,81 @@
+;;; org-roam-refill-previews.el --- Refill org-roam backlink previews  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2022  Chris Barrett
+
+;; Author: Chris Barrett <chris@walrus.cool>
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Refills previews displayed in the org-roam buffer to aid reabability in
+;; narrow window layouts.
+
+;; Note that this only works when preview sections are lazily computed, or the
+;; buffer is refreshed.
+
+;; Example configuration:
+;;
+;;   (use-package org-roam-refill-previews
+;;     :after org-roam
+;;     :demand t
+;;     :config
+;;     (add-hook 'org-roam-preview-postprocess-functions #'org-roam-refill-previews))
+
+;;; Code:
+
+(require 'org)
+(require 'org-roam)
+(require 'seq)
+(require 'subr-x)
+
+(defgroup org-roam-refill-previews nil
+  "Fill previews in the org-roam backlinks buffer."
+  :group 'productivity
+  :prefix "org-roam-refill-previews-")
+
+
+(defcustom org-roam-refill-previews-justify-p t
+  "Whether to justify preview text."
+  :group 'org-roam-refill-previews
+  :type 'boolean)
+
+;;; Code:
+(defun org-roam-refill-previews--window-width ()
+  (if-let* ((win (seq-find
+                  (lambda (it)
+                    (with-selected-window it
+                      (derived-mode-p 'org-roam-mode)))
+                  (window-list))))
+      (window-width win)
+    fill-column))
+
+(defun org-roam-refill-previews (preview-str)
+  "Refill PREVIEW-STR to fit the backlinks window.
+
+Expected to be appended to `org-roam-preview-postprocess-functions'."
+  (let ((fill-column (org-roam-refill-previews--window-width)))
+    (with-temp-buffer
+      (insert (org-fontify-like-in-org-mode preview-str))
+      (goto-char (point-max))
+      (skip-chars-backward " \t\n")
+      (while (not (bobp))
+        (ignore-errors
+          (org-fill-element (when org-roam-refill-previews-justify-p 'justify)))
+        (org-backward-paragraph))
+      (buffer-string))))
+
+(provide 'org-roam-refill-previews)
+
+;;; org-roam-refill-previews.el ends here