some improvements

bdio-mode.el

-;;; bdio-mode.el --- View .bdio files using lsbdio
+;;; bdio-mode.el --- View .bdio files using lsbdio -*- lexical-binding: t; -*-
 (require 's)
 (require 'f)
 
-(defvar bdio-mode-hook nil)
-(defvar source-file nil)
-(defvar lsbdio "lsbdio")
+(defvar-local bdio-mode--source-file nil)
 
-(defun bdio--render-file (file)
+(defgroup bdio nil
+  "BDIO viewer."
+  :group 'tools)
+
+(defcustom bdio-lsbdio "lsbdio"
+  "Path to the lsbdio executable."
+  :type 'string
+  :group 'bdio)
+
+
+(defun bdio-mode--render-file (file)
   "Render FILE using lsbdio into current buffer."
   (let ((inhibit-read-only t))
     (erase-buffer)
     (let ((exit-code
-	   (call-process lsbdio nil t nil file "-c 0")))
+	   (call-process bdio-lsbdio nil t nil file "-c 0")))
       (unless (eq exit-code 0)
 	(insert (format "Error running lsbdio on %s\n" file))))
     (goto-char (point-min))
@@ -24,26 +32,25 @@
 	))))
 
 
-(defun bdio-open-file ()
+(defun bdio-mode--open-file ()
   "Open .bdio file using lsbdio."
-  (setq source-file buffer-file-name)
+  ;;(setq-local bdio-mode--source-file buffer-file-name)
   (let ((file (buffer-file-name)))
     (when file
       (rename-buffer
        (format "*BDIO* %s" (file-name-nondirectory file)) t)
       (set-visited-file-name nil t)
       (bdio-mode)
-      (bdio--render-file file))))
+      (bdio-mode--render-file file))))
 
 
-(defun bdio-toggle-record ()
+(defun bdio-mode--toggle-record ()
   "Expand/collapse current record."
   (interactive)
-  (setq bdio-file source-file)
-  (setq lstart (line-beginning-position)
-	lend (line-end-position)
-	cpoint (point))
-
+  (let  ((bdio-file bdio-mode--source-file)
+	 (setq lstart (line-beginning-position))
+	 (lend (line-end-position))
+	 (cpoint (point)))
     (let* ((record (get-text-property lstart 'bdio-record))
 	   (inhibit-read-only t))
       (when record
@@ -61,17 +68,14 @@
 	    (insert "\n")
 	    (let ((output-start (point)))
 	      ;; insert command output
-	  (call-process lsbdio  nil t nil bdio-file "-d" (number-to-string record)))
+	      (call-process bdio-lsbdio  nil t nil bdio-file "-d" (number-to-string record)))
 	    ;; mark inserted region
 	    (put-text-property lstart lend 'bdio-expanded t)))))
-  (goto-char cpoint))
-;;               ;; optional face
-;;               (add-text-properties
-;;                output-start
-;;                (point)
-;;                '(face shadow)))))))))
+    (goto-char cpoint)))
 
-(setq-local revert-buffer-function #'bdio-revert-buffer)
+(defun bdio-mode--refresh-file (&rest ARGS)
+  (interactive)
+  (bdio-mode--render-file bdio-mode--source-file))
 
 (defun bdio-mode--clone-repo (dir)
   (message "cloning bdio in " dir)
@@ -91,42 +95,40 @@
 
 (defun bdio-mode--make-tools (bdio-dir)
   (message "making tools")
-  (defvar current-dir default-directory)
-  (cd bdio-dir)
-  (call-process "make" nil nil nil)
-  (cd "tools")
-  (call-process "make" nil nil nil)
-  (cd current-dir))
+  (let ((default-directory bdio-dir))
+    (call-process "make" nil nil nil))
 
-(defun bdio-mode--get-lsbdio ()
-  (defvar bdio-dir (f-join package-user-dir "bdio"))
+  (let ((default-directory (expand-file-name "tools" bdio-dir)))
+    (call-process "make" nil nil nil)))
 
-  (if (not (file-directory-p bdio-dir))
+(defun bdio-mode--get-lsbdio ()
+  (let* ((bdio-dir (expand-file-name "bdio" package-user-dir))
+	 (lsbdio-path
+	  (expand-file-name "tools/lsbdio" bdio-dir)))
+    (unless (file-directory-p bdio-dir)
       (bdio-mode--clone-repo bdio-dir))
-  (defvar lsbdio-path (f-join bdio-dir "tools" lsbdio))
-  (if (not (file-exists-p lsbdio-path))
+    (unless (file-exists-p lsbdio-path)
       (bdio-mode--make-tools bdio-dir))
-  (setq lsbdio (f-join bdio-dir "tools" lsbdio)))
+    (setq bdio-lsbdio lsbdio-path)))
 
 (defun bdio-mode--check-for-lsbdio ()
   (interactive)
-  (if (not (executable-find lsbdio))
+  (unless (executable-find bdio-lsbdio)
       (bdio-mode--get-lsbdio)))
 
-
 ;;;###autoload
-(add-to-list 'auto-mode-alist '("\\.bdio\\'" . bdio-open-file))
+(add-to-list 'auto-mode-alist '("\\.bdio\\'" . bdio-mode))
 
 (defvar bdio-mode-map
   (let ((map (make-sparse-keymap)))
-    (keymap-set map "<tab>" #'bdio-toggle-record)
+    (keymap-set map "<tab>" #'bdio-mode--toggle-record)
     map))
 
 (define-derived-mode bdio-mode special-mode "BDIO"
   "Major mode for viewing BDIO files via lsbdio."
-  (use-local-map bdio-mode-map)
   (bdio-mode--check-for-lsbdio)
-  (setq buffer-read-only t))
-
+  (setq-local revert-buffer-function #'bdio-mode--refresh-file)
+  (setq-local bdio-mode--source-file buffer-file-name)
+  (when bdio-mode--source-file (bdio-mode--render-file bdio-mode--source-file)))
 
 (provide 'bdio-mode)