;;; bad-alpha.el --- interface to frame transparency -*- lexical-binding: t -*-
;;
;;; Commentary:
;;
;; This is an interface to the transparency parameter of an Emacs frame a.k.a.
;; a window in a window system, e.g. X11 if it doesn't work it is likely one
;; doesn't have a composition manager, for Linux/X, try 'picom --backend glx &'
;; in ~/.xinitrc.
;;
;; (bad-alpha 0.3)   ; 30%
;; (bad-alpha)       ; return
;; M-x bad-alpha RET ; echo
;;
;; (bad-alpha-inc 0.1) ; +10%
;; (bad-alpha-dec 0.1) ; decrease same
;; (bad-alpha-inc)     ; default = 1.25%
;; (bad-alpha-dec)     ; same
;;
;; (bad-alpha-7) a.k.a. (bad-alpha-full)  ; 100%
;; (bad-alpha-6)                          ; 86%
;; (bad-alpha-5) a.k.a. (bad-alpha-huge)  ; 71%
;; (bad-alpha-4)                          ; 57%
;; (bad-alpha-3) a.k.a. (bad-alpha-some)  ; 42%
;; (bad-alpha-2)                          ; 29%
;; (bad-alpha-1) a.k.a. (bad-alpha-tiny)  ; 14%
;; (bad-alpha-0) a.k.a. (bad-alpha-none)  ;  0%
;;
;;; Code:

(require 'cl-lib)
(cl-pushnew "." load-path :test #'string=)
(require 'luki-lisp)

(defun bad-alpha (&optional alpha) (i)
  (if (and (! alpha) (! (called-interactively-p 'interactive)))
      (- 1 (frame-parameter nil 'alpha-background))
    (when (n alpha)
      (setf alpha (min 1.0 (max 0.0 alpha)))
      (set-frame-parameter nil 'alpha-background (- 1 alpha)))
    ($ "alpha: %.0f%%" (* 100 (- 1 (frame-parameter nil 'alpha-background))))))

(defun bad-alpha-7 () (i) (bad-alpha  1  ))
(defun bad-alpha-6 () (i) (bad-alpha .86 ))
(defun bad-alpha-5 () (i) (bad-alpha .71 ))
(defun bad-alpha-4 () (i) (bad-alpha .57 ))
(defun bad-alpha-3 () (i) (bad-alpha .42 ))
(defun bad-alpha-2 () (i) (bad-alpha .29 ))
(defun bad-alpha-1 () (i) (bad-alpha .14 ))
(defun bad-alpha-0 () (i) (bad-alpha  0  ))

(defalias 'bad-alpha-full #'bad-alpha-7)
(defalias 'bad-alpha-huge #'bad-alpha-5)
(defalias 'bad-alpha-some #'bad-alpha-3)
(defalias 'bad-alpha-tiny #'bad-alpha-1)
(defalias 'bad-alpha-none #'bad-alpha-0)

(defun bad-alpha-inc (&optional step) (i) (or step (setf step 0.125)) (bad-alpha (+ (bad-alpha) step)))
(defun bad-alpha-dec (&optional step) (i) (or step (setf step 0.125)) (bad-alpha-inc (- step)))

(<- 'bad-alpha)
;;; bad-alpha.el ends here