Advanced Customization, How Does Xah Fly Keys Work

2022-01-14 xtodo work in progress. may be outdated.

Advanced Customization, How Does Xah Fly Keys Work

If you look at the file, in 10 minutes you should have a basic idea. The code is simple.

There's these 2 important variables:

xah-fly-key-map

Variable. Value is a elisp keymap. This keymap is used for command mode and insertion mode.

xah-fly-leader-key-map

Variable. Value is a elisp keymap. It's the leader keys sequence.

(note: in elisp, keymap is just a list of key/command pairs. The command part can be another keymap, in which case, it is a key sequence.)

There's these 2 important commands:

xah-fly-command-mode-init

set keybinding for command mode. Basically, it just modify xah-fly-key-map.

xah-fly-insert-mode-init

set keybinding for insert mode. Basically, it just modify xah-fly-key-map, by setting all keys to nil (which means, do emacs default, usually means they do self-insert-command).

xah-fly-command-mode-init looks like this:

(defun xah-fly-command-mode-init ()
  (xah-fly--define-keys
   xah-fly-key-map
   '(

     ("a" . execute-extended-command)
     ("b" . isearch-forward)
     ("c" . previous-line)
     ;; more here

     )))

The "a" "b" "c" there are Dvorak keys.

The function xah-fly--define-keys takes care of translating Dvorak to QWERTY, if user has qwery set (xah-fly-keys-set-layout 'qwerty) .

xah-fly-insert-mode-init looks like this:

(defun xah-fly-insert-mode-init ()
  (xah-fly--define-keys
   xah-fly-key-map
   '(

     ("a" . nil)
     ("b" . nil)
     ("c" . nil)

     ;; more
     )))

xah-fly-leader-key-map looks like this:

(xah-fly--define-keys
 (define-prefix-command 'xah-fly-leader-key-map)
 '(

   ("a" . mark-whole-buffer)
   ("b" . end-of-buffer)
   ("c" . xah-fly-c-keymap)
   ("d" . beginning-of-buffer)
   ("e" . xah-fly-e-keymap)
   ("f" . xah-search-current-word)

   ;; more
   ))

For example, the line ("b" . end-of-buffer) means press leader b will call end-of-buffer.

Note: All keys in the file are Dvorak keys. For example, if you see ("b" . isearch-forward), that's Dvorak b, and when user has QWERTY set, that b is automatically translated to n.