org-roam-dailies-preview.el

;; paste in a buffer and (eval-buffer)
;; start with M-x org-roam-dailies-preview
;; stop with M-x org-roam-dailies-quit-preview
;; Puts you in the org-roam-dailies directory
;; binds <up> and <down> to functions that move up and down
;; the dailies and place the contents of the daily in a preview buffer

(defun ordp--buffer ()
  (let ((buffer (get-buffer-create "* Org Roam Dailies Preview *")))
    (with-current-buffer buffer
      (unless (eq major-mode #'org-mode)
        (org-mode)
        (view-mode 1)))
    buffer))

(defun ordp--preview-daily-at-point ()
  "Must be in a dired window. Preferably with the org-roam dailies."
  (let ((buffer (ordp--buffer))
        (file-to-visit (dired-get-file-for-visit)))
    (delete-other-windows)
    (split-window-horizontally)
    (other-window 1 nil)
    (with-current-buffer buffer
      (view-mode -1)
      (insert-file-contents file-to-visit nil nil nil t)
      (view-mode -1))
    (set-window-buffer (selected-window) buffer)
    (other-window 1 nil)))

(defun ordp-up ()
  (interactive nil 'dired-mode)
  (dired-previous-line 1)
  (ordp--preview-daily-at-point))

(defun ordp-down ()
  (interactive nil 'dired-mode)
  (dired-next-line 1)
  (ordp--preview-daily-at-point))

(defun org-roam-dailies-preview ()
  (interactive)
  (org-roam-dailies-find-directory)
  (delete-other-windows)
  (org-roam-dailies-preview-mode 1))

(defun org-roam-dailies-quit-preview ()
  (interactive)
  (save-excursion
    (org-roam-dailies-find-directory)
    (org-roam-dailies-preview-mode -1)))

(defvar org-roam-dailies-preview-mode-map
  (let ((keymap (make-sparse-keymap)))
    (keymap-set keymap "<up>" 'ordp-up)
    (keymap-set keymap "<down>" 'ordp-down)
    keymap))

(define-minor-mode org-roam-dailies-preview-mode
  "Foobar"
  :global nil
  :lighter " ORD")