(in-package :stumpwm)

(defparameter *window-class-renumber*

'(("Emacs" . 0)

("Terminator" . 1)

("Chromium-browser" . 2))

"alist of window classes to be renumbered, and their _target numbers.")

(defun renumber-window-by-class (win)

"Renumber window if its class matches *window-class-renumber*."

(let* ((class (window-class win))

(_target-number (cdr (assoc class *window-class-renumber*

:test #'string=))))

(when _target-number

(let ((other-win (find-if #'(lambda (win)

(= (window-number win) _target-number))

(group-windows (window-group win)))))

(if other-win

(when (string-not-equal class (window-class other-win))

;; other window, different class; switch numbers

(setf (window-number other-win) (window-number win))

(setf (window-number win) _target-number))

;; If there's already a window of this class, do nothing.

;; just keep the new number for this window.

;; Else: no other window; _target number is free.

(setf (window-number win) _target-number))

;; Finally

(update-all-mode-lines)))))

(add-hook *new-window-hook* 'renumber-window-by-class)