From a4b634cf9cc82cb1c0f85281471b5f9d120f814e Mon Sep 17 00:00:00 2001
From: Case Duckworth
Date: Sun, 26 Dec 2021 13:02:43 -0600
Subject: Customize 'customize'

---
 init.el           | 18 ++++++++++++++
 lisp/+cus-edit.el | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 lisp/+cus-edit.el

diff --git a/init.el b/init.el
index 45133df..835af08 100644
--- a/init.el
+++ b/init.el
@@ -136,6 +136,24 @@
            calendar-latitude _location-latitude
            calendar-longitude _location-longitude))
 
+(setup cus-edit
+  ;; I don't use Custom to actually /make/ any customizations, but it's handy to
+  ;; (A) see what options are available and (B) persist some changes across
+  ;; restarts, for example, `safe-local-variables'.
+  (:also-load +cus-edit)
+  (:option custom-file (private/ "custom.el")
+           custom-magic-show nil
+           custom-magic-show-button t
+           custom-raised-buttons nil
+           custom-unlispify-tag-names nil
+           custom-variable-default-form 'lisp
+           +custom-variable-allowlist '(safe-local-variable-values))
+  (when (file-exists-p custom-file)
+    (+custom-load-ignoring-most-customizations t))
+  (advice-add 'custom-buffer-create-internal :after '+cus-edit-expand-widgets)
+  (:with-mode Custom-mode
+    (:local-set imenu-generic-expression +cus-edit-imenu-generic-expression)))
+
 (setup dired
   (:also-load dired-x)
   (:also-straight dired-subtree
diff --git a/lisp/+cus-edit.el b/lisp/+cus-edit.el
new file mode 100644
index 0000000..2f9769d
--- /dev/null
+++ b/lisp/+cus-edit.el
@@ -0,0 +1,72 @@
+;;; +cus-edit.el -*- lexical-binding: t; -*-
+
+;;; Commentary:
+
+;; The naming convention for this library, called "cus-edit.el" on the
+;; filesystem, is all over the damn place.  Whatever.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'seq)
+
+(defgroup +customize nil
+  "Extra customize customizations."
+  :prefix "+customize-"
+  :group 'customize)
+
+(defcustom +cus-edit-imenu-generic-expression ; thanks u/oantolin!
+  `(("Faces" ,(rx (seq bol
+                      (or "Show" "Hide") " "
+                      (group (zero-or-more nonl))
+                      " face: [sample]"))
+     1)
+    ("Variables" ,(rx (seq bol
+                          (or "Show Value" "Hide") " "
+                          (group (zero-or-more
+                                  (not (any "\n:"))))))
+     1))
+  "Show faces and variables in `imenu' in a `customize' buffer."
+  :type 'sexp                           ; This is .. over-simplified.
+  )
+
+(defcustom +custom-variable-allowlist nil
+  "Variables to allow changing while loading the Custom file.")
+
+(defun +custom-load-ignoring-most-customizations (&optional
+                                                     noerror
+                                                     nomessage
+                                                     nosuffix
+                                                     must-suffix)
+  "Load `custom-file', ignoring most customizations.
+Ignore all faces, and only load variables in
+`+customize-variable-allowlist'.  All the optional
+variables---NOERROR, NOMESSAGE, NOSUFFIX, MUST-SUFFIX---are
+passed on to `load'."
+  (cl-letf (((symbol-function 'custom-set-faces) 'ignore)
+            ((symbol-function 'custom-set-variables)
+             (lambda (&rest args)
+               (apply 'custom-theme-set-variables 'user
+                      (seq-filter (lambda (el)
+                                    (memq (car el)
+                                          +customize-variable-allowlist))
+                                  args)))))
+    (load custom-file noerror nomessage nosuffix must-suffix)))
+
+(defun +cus-edit-expand-widgets (&rest _)
+  "Expand descriptions in `Custom-mode' buffers."
+  (interactive)
+  ;; "More/Hide" widgets (thanks alphapapa!)
+  (widget-map-buttons (lambda (widget _)
+                        (pcase (widget-get widget :off)
+                          ("More" (widget-apply-action widget)))
+                        nil))
+  ;; "Show Value" widgets (the little triangles)
+  (widget-map-buttons (lambda (widget _)
+                        (pcase (widget-get widget :off)
+                          ("Show Value"
+                           (widget-apply-action widget)))
+                        nil)))
+
+(provide '+cus-edit)
+;;; +cus-edit.el ends here
-- 
cgit 1.4.1-21-gabe81