1 //! Enumerate devices in the alsa library configuration
2 //!
3 //! # Example
4 //! Print all devices found in various categories.
5 //!
6 //! ```
7 //! use std::ffi::CString;
8 //! use alsa::device_name::HintIter;
9 //!
10 //! for t in &["pcm", "ctl", "rawmidi", "timer", "seq", "hwdep"] {
11 //! println!("{} devices:", t);
12 //! let i = HintIter::new(None, &*CString::new(*t).unwrap()).unwrap();
13 //! for a in i { println!(" {:?}", a) }
14 //! }
15 //! ```
16
17 use std::ptr;
18 use libc::{c_void, c_int};
19 use alsa;
20 use super::{Card, Direction};
21 use super::error::*;
22 use std::ffi::{CStr, CString};
23
24 /// [snd_device_name_hint](http://www.alsa-project.org/alsa-doc/alsa-lib/group___control.html) wrapper
25 pub struct HintIter(*mut *mut c_void, isize);
26
27 impl Drop for HintIter {
drop(&mut self)28 fn drop(&mut self) { unsafe { alsa::snd_device_name_free_hint(self.0); }}
29 }
30
31 impl HintIter {
32 /// typical interfaces are: "pcm", "ctl", "rawmidi", "timer", "seq" and "hwdep".
new(card: Option<&Card>, iface: &CStr) -> Result<HintIter>33 pub fn new(card: Option<&Card>, iface: &CStr) -> Result<HintIter> {
34 let mut p = ptr::null_mut();
35 let cnr = card.map(|c| c.get_index()).unwrap_or(-1) as c_int;
36 acheck!(snd_device_name_hint(cnr, iface.as_ptr(), &mut p))
37 .map(|_| HintIter(p, 0))
38 }
39
40 /// A constructor variant that takes the interface as a Rust string slice.
new_str(card: Option<&Card>, iface: &str) -> Result<HintIter>41 pub fn new_str(card: Option<&Card>, iface: &str) -> Result<HintIter> {
42 HintIter::new(card, &CString::new(iface).unwrap())
43 }
44 }
45
46 impl Iterator for HintIter {
47 type Item = Hint;
next<'a> (&'a mut self) -> Option<Hint>48 fn next<'a> (&'a mut self) -> Option<Hint> {
49 if self.0.is_null() { return None; }
50 let p = unsafe { *self.0.offset(self.1) };
51 if p.is_null() { return None; }
52 self.1 += 1;
53 Some(Hint::new(p))
54 }
55 }
56
57
58 /// [snd_device_name_get_hint](http://www.alsa-project.org/alsa-doc/alsa-lib/group___control.html) wrapper
59 #[derive(Debug, Clone)]
60 pub struct Hint {
61 pub name: Option<String>,
62 pub desc: Option<String>,
63 pub direction: Option<Direction>,
64 }
65
66 impl Hint {
get_str(p: *const c_void, name: &str) -> Option<String>67 fn get_str(p: *const c_void, name: &str) -> Option<String> {
68 let c = unsafe { alsa::snd_device_name_get_hint(p, CString::new(name).unwrap().as_ptr()) };
69 from_alloc("snd_device_name_get_hint", c).ok()
70 }
71
new(p: *const c_void) -> Hint72 fn new(p: *const c_void) -> Hint {
73 let d = Hint::get_str(p, "IOID").and_then(|x| match &*x {
74 "Input" => Some(Direction::Capture),
75 "Output" => Some(Direction::Playback),
76 _ => None,
77 });
78 Hint { name: Hint::get_str(p, "NAME"), desc: Hint::get_str(p, "DESC"), direction: d }
79 }
80 }
81
82 #[test]
print_hints()83 fn print_hints() {
84 for t in &["pcm", "ctl", "rawmidi", "timer", "seq", "hwdep"] {
85 println!("{} devices:", t);
86 let i = HintIter::new(None, &*CString::new(*t).unwrap()).unwrap();
87 for a in i { println!(" {:?}", a) }
88 }
89 }
90