Add a layer variable osx-swap-option-and-command

set to non-nil to swap command and option key on macOS

CHANGELOG.develop

@@ -2068,6 +2068,8 @@ Other:
 - Fixed key binding issue when Emacs is launched in daemon mode.
 - Added the default value =H-= (hyper) to =kbd-mac-command= if it's neither:
   =hyper=, =super= or =alt= (thanks to Binbin Ye)
+- Added a layer variable =osx-swap-option-and-command= defaults to =nil=
+  (thanks to Binbin Ye)
 **** Pandoc
 - Fixed =spacemacs/run-pandoc= not to reset =pandoc--local-settings=
   (thanks to martian-f)

layers/+os/osx/README.org

@@ -47,13 +47,15 @@ The different modifier keys can be set as follows:
                      osx-function-as      nil
                      osx-right-command-as 'left
                      osx-right-option-as  'left
-                     osx-right-control-as 'left))
+                     osx-right-control-as 'left
+                     osx-swap-option-and-command nil))
 #+END_SRC
 
 These are also the default values. Setting the right modifier to =left=
 will equal the left modifier. Allowed values are: =super=, =meta=, =control=,
 =alt= and =nil=.
 Setting =nil= for modifiers will leave the left modifiers as emacs default.
+Setting =osx-swap-option-and-command= to =t= will swap =command= and =option= key.
 
 *** Use with non-US keyboard layouts
 If you need the ~⌥~ key to type common characters such as ={[]}~= which is usual

layers/+os/osx/config.el

@@ -60,6 +60,9 @@
 (defvar osx-use-dictionary-app t
   "If non nil use osx dictionary app instead of wordnet")
 
+(defvar osx-swap-option-and-command nil
+  "If non nil swap option key and command key")
+
 ;; Use the OS X Emoji font for Emoticons
 (when (fboundp 'set-fontset-font)
   (set-fontset-font "fontset-default"

layers/+os/osx/keybindings.el

@@ -45,6 +45,9 @@
              (when (member key-value allowed-values)
                (setf (symbol-value internal-var) key-value))))
 
+  (when osx-swap-option-and-command
+    (cl-rotatef mac-command-modifier mac-option-modifier))
+
   (defun kbd-mac-command (keys)
     "Wraps `kbd' function with Mac OSX compatible Command-key (⌘).
 KEYS should be a string such as \"f\" which will be turned into values