Add functions to restore custom buffer bookmark properties

README.org

@@ -684,11 +684,32 @@ have ~tab-bar-tab-post-open-functions~, the bookmark context will not
 be available when those functions are called.
 
 #+begin_src emacs-lisp
+  (add-hook 'bufferlo-bookmark-map-functions #'buffer-bookmark-store-fun)
+  (add-hook 'bufferlo-bookmark-buffer-handler-functions #'buffer-bookmark-restore-fun)
   (add-hook 'bufferlo-bookmark-tab-handler-functions #'tab-bookmark-fun)
   (add-hook 'bufferlo-bookmark-frame-handler-functions #'frame-bookmark-fun)
   (add-hook 'bufferlo-bookmark-set-handler-functions #'set-bookmark-fun)
 #+end_src
 
+There are buffer-bookmark convenience functions you can use to persist
+text-scale-mode-amount, and persist buffer-local variables (though you should
+prefer [[https://www.gnu.org/software/emacs/manual/html_node/emacs/File-Variables.html][file-local variables]], and directory variables [[https://www.gnu.org/software/emacs/manual/html_node/emacs/Directory-Variables.html][directory variables]] and
+take care to store buffer local variables that you consider safe to restore,
+see [[https://www.gnu.org/software/emacs/manual/html_node/elisp/File-Local-Variables.html#index-safe_002dlocal_002dvariable_002dp][risky-local-variable-p]]).
+
+Note: These need to be bound before ~bufferlo-mode~ is enabled.
+
+#+begin_src emacs-lisp
+  ;; To persist text-scale-mode-amount
+  (setq bufferlo-bookmark-buffer-locals t)
+#+end_src
+
+#+begin_src emacs-lisp
+  ;; To persist buffer-local variables
+  (setq bufferlo-bookmark-text-scale-mode-amount t)
+  (setq bufferlo-bookmark-buffer-local-variables '(my:special-local-1 my:special-local-2))
+#+end_src
+
 *** Frame geometry options
 
 Bufferlo provides wrappers around Emacs frame functions to provide
@@ -1133,6 +1154,8 @@ remain in force until they are saved if this policy is set to t.
     (setq bufferlo-prefer-local-buffers 'tabs)
     (setq bufferlo-ibuffer-bind-local-buffer-filter t)
     (setq bufferlo-ibuffer-bind-keys t)
+    (setq bufferlo-bookmark-buffer-locals t)
+    (setq bufferlo-bookmark-text-scale-mode-amount t)
     :config
     (setq bufferlo-mode-line-prefix "🐃") ; "🐮"
     (setq bufferlo-mode-line-set-active-prefix "Ⓢ")
@@ -1173,6 +1196,7 @@ remain in force until they are saved if this policy is set to t.
     (setq bufferlo-bookmark-frame-save-on-delete 'when-bookmarked)
     (setq bufferlo-bookmark-tab-save-on-close 'when-bookmarked)
     (setq bufferlo-close-tab-kill-buffers-prompt t)
+    (setq bufferlo-bookmark-buffer-local-variables '(tab-width))
     (setq bufferlo-bookmark-frame-load-make-frame 'restore-geometry)
     (setq bufferlo-bookmark-frame-load-policy 'prompt)
     (setq bufferlo-bookmark-frame-duplicate-policy 'prompt)

bufferlo.el

@@ -191,6 +191,36 @@ This overrides buffers excluded by `bufferlo-bookmark-buffers-exclude-filters'."
   :package-version '(bufferlo . "1.1")
   :type '(repeat regexp))
 
+(defcustom bufferlo-bookmark-buffer-local-variables '()
+  "List of buffer-local variables to store/restore in/from buffer bookmarks.
+This is a list of symbols; e.g., \\='(my:special-local my:special-local-2).
+
+To use this, add the function
+`bufferlo-bookmark-map-function-buffer-locals` to
+`bufferlo-bookmark-map-functions` to store buffer locals, and its
+corollary function `bufferlo-bookmark-buffer-handler-buffer-locals`
+`bufferlo-bookmark-buffer-handler-functions` to restore them when a
+bufferlo buffer bookmark is restored.
+
+Note: Local file variables and directory variables are the preferred
+methods for managing buffer-local variables.  Use this facility only
+when necessary.
+
+See Info nodes `(elisp) File Local Variables' and `(elisp) Directory
+Local Variables'."
+  :package-version '(bufferlo . "1.3")
+  :type '(repeat symbol))
+
+(defcustom bufferlo-bookmark-buffer-locals t
+  "If non-nil, enable bookmark buffer-local variable persistence."
+  :package-version '(bufferlo . "1.3")
+  :type 'boolean)
+
+(defcustom bufferlo-bookmark-text-scale-mode-amount t
+  "If non-nil, enable bookmark `text-scale-mode-amount` persistence."
+  :package-version '(bufferlo . "1.3")
+  :type 'boolean)
+
 (defcustom bufferlo-bookmark-frame-load-make-frame nil
   "If non-nil, create a new frame to hold a loaded frame bookmark.
 Set to \\='restore-geometry to restore the frame geometry to that
@@ -628,6 +658,17 @@ frame bookmark is a collection of tab bookmarks."
   :package-version '(bufferlo . "0.8")
   :type 'hook)
 
+(defcustom bufferlo-bookmark-buffer-handler-functions nil
+  "Abnormal hooks to call after a bookmark buffer is handled.
+This is the corollary to `bufferlo-bookmark-map-functions` to process
+extra properties added to a buffer bookmark.
+
+Each function is called with the restored buffer current, and with the
+following arguments:
+  bookmark-record: See `bookmark-make-record-default`."
+  :package-version '(bufferlo . "1.3")
+  :type 'hook)
+
 (defcustom bufferlo-bookmark-tab-handler-functions nil
   "Abnormal hooks to call after a bookmark tab is handled.
 Each function takes the following arguments:
@@ -1004,7 +1045,7 @@ string, FACE is the face for STR."
                                  #'string-equal)))
     (setq bufferlo--command-line-noload pos)
     (setq command-line-args (seq-remove-at-position command-line-args pos)))
-  (when (file-exists-p (expand-file-name "bufferlo-noload" user-emacs-directory))
+  (when (locate-user-emacs-file "bufferlo-noload")
     (message "bufferlo-noload file found; inhibiting bufferlo bookmark loading")
     (setq bufferlo--command-line-noload t)))
 
@@ -1100,7 +1141,13 @@ string, FACE is the face for STR."
                   #'bufferlo-bookmark--tab-save-on-close)
         (add-hook 'delete-frame-functions
                   #'bufferlo-bookmark--frame-save-on-delete)
-        ;; bookmark advice
+        (when bufferlo-bookmark-buffer-locals
+          (add-hook 'bufferlo-bookmark-map-functions #'bufferlo-bookmark-map-function-buffer-locals)
+          (add-hook 'bufferlo-bookmark-buffer-handler-functions #'bufferlo-bookmark-buffer-handler-buffer-locals))
+        (when bufferlo-bookmark-text-scale-mode-amount
+          (add-hook 'bufferlo-bookmark-map-functions #'bufferlo-bookmark-map-function-text-scale-mode-amount)
+          (add-hook 'bufferlo-bookmark-buffer-handler-functions #'bufferlo-bookmark-buffer-handler-text-scale-mode-amount))
+        ;; bookmark commands advice
         (advice-add #'bookmark--jump-via :around #'bufferlo--bookmark--jump-via-advice)
         (advice-add #'bookmark-rename :around #'bufferlo--bookmark-rename-advice)
         (advice-add #'bookmark-delete :around #'bufferlo--bookmark-delete-advice)
@@ -1148,7 +1195,19 @@ string, FACE is the face for STR."
                  #'bufferlo-bookmark--tab-save-on-close)
     (remove-hook 'delete-frame-functions
                  #'bufferlo-bookmark--frame-save-on-delete)
-    ;; bookmark advice
+    ;; bufferlo-bookmark-buffer-locals
+    (progn
+      (remove-hook 'bufferlo-bookmark-map-functions
+                   #'bufferlo-bookmark-map-function-buffer-locals)
+      (remove-hook 'bufferlo-bookmark-buffer-handler-functions
+                   #'bufferlo-bookmark-buffer-handler-buffer-locals))
+    ;; bufferlo-bookmark-text-scale-mode-amount
+    (progn
+      (remove-hook 'bufferlo-bookmark-map-functions
+                   #'bufferlo-bookmark-map-function-text-scale-mode-amount)
+      (remove-hook 'bufferlo-bookmark-buffer-handler-functions
+                   #'bufferlo-bookmark-buffer-handler-text-scale-mode-amount))
+    ;; bookmark commands advice
     (advice-remove #'bookmark--jump-via #'bufferlo--bookmark--jump-via-advice)
     (advice-remove #'bookmark-rename #'bufferlo--bookmark-rename-advice)
     (advice-remove #'bookmark-delete #'bufferlo--bookmark-delete-advice)))
@@ -2380,6 +2439,62 @@ empty (no-op) display-func."
                                       err bookmark)))
       nil)))
 
+(defun bufferlo-bookmark-map-function-buffer-locals (bookmark-record)
+  "Store buffer local variables in BOOKMARK-RECORD.
+Add this function to `bufferlo-bookmark-map-functions`, and add a list
+of symbols representing the variables you want to store in
+`bufferlo-buffer-locals`.
+
+These are restored upon buffer bookmark loading if
+`bufferlo-bookmark-buffer-handler-buffer-locals` is a member of
+`bufferlo-bookmark-buffer-handler-functions`.
+
+Note: Take care to store buffer local variables that you consider safe
+to restore, which see `risky-local-variable-p`."
+  (when-let* ((buffer-locals
+               (seq-filter
+                (lambda (x) (not (null x)))
+                (mapcar (lambda (sym)
+                          (when (local-variable-p sym)
+                            (cons sym (symbol-value sym))))
+                        bufferlo-bookmark-buffer-local-variables))))
+    (bookmark-prop-set bookmark-record
+                       'bufferlo-buffer-locals
+                       buffer-locals))
+  bookmark-record)
+
+(defun bufferlo-bookmark-buffer-handler-buffer-locals (bookmark-record)
+  "Restore buffer local variables from BOOKMARK-RECORD.
+See `bufferlo-bookmark-map-function-buffer-locals`."
+  (when-let*
+      ((buffer-locals
+        (bookmark-prop-get bookmark-record
+                           'bufferlo-buffer-locals)))
+    (mapc (lambda (pair)
+            (make-local-variable (car pair))
+            (set (car pair) (cdr pair)))
+          buffer-locals)))
+
+(defun bufferlo-bookmark-map-function-text-scale-mode-amount (bookmark-record)
+  "Store the buffer local `text-scale-mode-amount` in BOOKMARK-RECORD.
+Add this function to `bufferlo-bookmark-map-functions`, and its
+corollary `bufferlo-bookmark-buffer-handler-text-scale-mode-amount`
+to`bufferlo-bookmark-buffer-handler-functions`."
+  (when text-scale-mode-amount
+    (bookmark-prop-set bookmark-record
+                       'bufferlo-text-scale-mode-amount
+                       text-scale-mode-amount))
+  bookmark-record)
+
+(defun bufferlo-bookmark-buffer-handler-text-scale-mode-amount (bookmark-record)
+  "Restore `text-scale-mode-amount` from BOOKMARK-RECORD.
+See `bufferlo-bookmark-map-function-text-scale-mode-amount`."
+  (when-let*
+      ((val
+        (bookmark-prop-get bookmark-record
+                           'bufferlo-text-scale-mode-amount)))
+    (text-scale-set val)))
+
 (defun bufferlo--bookmark-get-for-buffer (buffer)
   "Get `buffer-name' and bookmark for BUFFER."
   (with-current-buffer buffer
@@ -2781,6 +2896,9 @@ Returns nil on success, non-nil on abort."
                                         (funcall (or (bookmark-get-handler record)
                                                      'bookmark-default-handler)
                                                  record)
+                                        (run-hook-with-args
+                                         'bufferlo-bookmark-buffer-handler-functions
+                                         record)
                                         (run-hooks 'bookmark-after-jump-hook)
                                         nil)
                                     (error