1 ;;; sndio.el --- Interact with sndio(8)  -*- lexical-binding: t; -*-
2 
3 ;; Copyright (C) 2020 Omar Polo
4 
5 ;; Author: Omar Polo <op@omarpolo.com>
6 ;; Version: 1.0
7 ;; Keywords: multimedia
8 ;; URL: https://git.omarpolo.com/sndioctl.el
9 
10 ;;; Commentary:
11 
12 ;; This package provides the sndio major mode to interact with
13 ;; OpenBSD' sndio(8).
14 
15 ;;; Code:
16 
17 (require 'cl-lib)
18 
19 (defvar sndioctl-cmd "sndioctl"
20   "Path to the sndioctl executable.")
21 
22 (defvar sndio-step 0.02
23   "Step for `sndio-increase' and `sndio-decrease'.")
24 
25 (define-derived-mode sndio-mode special-mode "sndio"
26   "Major mode for sndio interaction."
27 
28   (define-key sndio-mode-map (kbd "n") #'forward-line)
29   (define-key sndio-mode-map (kbd "p") #'previous-line)
30   (define-key sndio-mode-map (kbd "i") #'sndio-increase)
31   (define-key sndio-mode-map (kbd "d") #'sndio-decrease)
32   (define-key sndio-mode-map (kbd "m") #'sndio-mute)
33   (define-key sndio-mode-map (kbd "t") #'sndio-toggle)
34   (define-key sndio-mode-map (kbd "g") #'sndio-update)
35 
36   (buffer-disable-undo)
37 
38   (sndio-update))
39 
40 (defun sndio-update ()
41   "Update the current sndio buffer."
42   (interactive)
43   (with-current-buffer "*sndio*"
44     (save-excursion
45       (let ((inhibit-read-only t))
46         (erase-buffer)
47         (process-file sndioctl-cmd nil (current-buffer) nil)))))
48 
49 (defun sndio--run (&rest args)
50   "Run `sndioctl-cmd' with ARGS yielding its output."
51   (with-temp-buffer
52     (when (zerop (apply #'process-file sndioctl-cmd nil t nil args))
53       (buffer-string))))
54 
55 (defun sndio--current-io ()
56   "Yield the input/poutput at point as string."
57   (when-let (end (save-excursion
58                    (beginning-of-line)
59                    (ignore-errors (search-forward "="))))
60     (buffer-substring-no-properties (line-beginning-position)
61                                     (1- end))))
62 
63 (defun sndio--update-value (x)
64   "Update the value for the input/output at point setting it to X."
65   (save-excursion
66     (search-forward "=")
67     (let ((inhibit-read-only t))
68       (delete-region (point) (line-end-position))
69       (insert (string-trim-right x)))))
70 
71 (defun sndio-increase ()
72   "Increase the volume for the input/output at point."
73   (interactive)
74   (when-let (x (sndio--current-io))
75     (when-let (val (sndio--run "-n" (concat x "=+" (number-to-string sndio-step))))
76       (sndio--update-value val))))
77 
78 (defun sndio-decrease ()
79   "Decrease the volume for the input/output at point."
80   (interactive)
81   (when-let (x (sndio--current-io))
82     (when-let (val (sndio--run "-n" (concat x "=-" (number-to-string sndio-step))))
83       (sndio--update-value val))))
84 
85 (defun sndio-mute ()
86   "Mute the input/output at point."
87   (interactive)
88   (when-let (x (sndio--current-io))
89     (when-let (val (sndio--run "-n" (concat x "=0")))
90       (sndio--update-value val))))
91 
92 (defun sndio-toggle ()
93   "Toggle input/output at point."
94   (interactive)
95   (when-let (x (sndio--current-io))
96     (when-let (val (sndio--run "-n" (concat x "=!")))
97       (sndio--update-value val))))
98 
99 ;;;###autoload
100 (defun sndio ()
101   "Launch sndio."
102   (interactive)
103   (switch-to-buffer "*sndio*")
104   (sndio-mode))
105 
106 (provide 'sndio)
107 ;;; sndio.el ends here.