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   (define-key sndio-mode-map (kbd "d") #'kill-buffer)
36 
37   (buffer-disable-undo)
38 
39   (sndio-update))
40 
41 (defun sndio-update ()
42   "Update the current sndio buffer."
43   (interactive)
44   (with-current-buffer "*sndio*"
45     (save-excursion
46       (let ((inhibit-read-only t))
47         (erase-buffer)
48         (process-file sndioctl-cmd nil (current-buffer) nil)))))
49 
50 (defun sndio--run (&rest args)
51   "Run `sndioctl-cmd' with ARGS yielding its output."
52   (with-temp-buffer
53     (when (zerop (apply #'process-file sndioctl-cmd nil t nil args))
54       (buffer-string))))
55 
56 (defun sndio--current-io ()
57   "Yield the input/poutput at point as string."
58   (when-let (end (save-excursion
59                    (beginning-of-line)
60                    (ignore-errors (search-forward "="))))
61     (buffer-substring-no-properties (line-beginning-position)
62                                     (1- end))))
63 
64 (defun sndio--update-value (x)
65   "Update the value for the input/output at point setting it to X."
66   (save-excursion
67     (search-forward "=")
68     (let ((inhibit-read-only t))
69       (delete-region (point) (line-end-position))
70       (insert (string-trim-right x)))))
71 
72 (defun sndio-increase ()
73   "Increase the volume for the input/output at point."
74   (interactive)
75   (when-let (x (sndio--current-io))
76     (when-let (val (sndio--run "-n" (concat x "=+" (number-to-string sndio-step))))
77       (sndio--update-value val))))
78 
79 (defun sndio-decrease ()
80   "Decrease the volume for the input/output at point."
81   (interactive)
82   (when-let (x (sndio--current-io))
83     (when-let (val (sndio--run "-n" (concat x "=-" (number-to-string sndio-step))))
84       (sndio--update-value val))))
85 
86 (defun sndio-mute ()
87   "Mute the input/output at point."
88   (interactive)
89   (when-let (x (sndio--current-io))
90     (when-let (val (sndio--run "-n" (concat x "=0")))
91       (sndio--update-value val))))
92 
93 (defun sndio-toggle ()
94   "Toggle input/output at point."
95   (interactive)
96   (when-let (x (sndio--current-io))
97     (when-let (val (sndio--run "-n" (concat x "=!")))
98       (sndio--update-value val))))
99 
100 ;;;###autoload
101 (defun sndio ()
102   "Launch sndio."
103   (interactive)
104   (switch-to-buffer "*sndio*")
105   (sndio-mode))
106 
107 (provide 'sndio)
108 ;;; sndio.el ends here.