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//! Enumerate devices in the alsa library configuration
//!
//! # Example
//! Print all devices found in various categories.
//!
//! ```
//! use std::ffi::CString;
//! use alsa::device_name::HintIter;
//!
//! for t in &["pcm", "ctl", "rawmidi", "timer", "seq", "hwdep"] {
//! println!("{} devices:", t);
//! let i = HintIter::new(None, &*CString::new(*t).unwrap()).unwrap();
//! for a in i { println!(" {:?}", a) }
//! }
//! ```
use std::ptr;
use libc::{c_void, c_int};
use crate::alsa;
use super::{Card, Direction};
use super::error::*;
use std::ffi::{CStr, CString};
/// [snd_device_name_hint](http://www.alsa-project.org/alsa-doc/alsa-lib/group___control.html) wrapper
pub struct HintIter(*mut *mut c_void, isize);
impl Drop for HintIter {
fn drop(&mut self) { unsafe { alsa::snd_device_name_free_hint(self.0); }}
}
impl HintIter {
/// typical interfaces are: "pcm", "ctl", "rawmidi", "timer", "seq" and "hwdep".
pub fn new(card: Option<&Card>, iface: &CStr) -> Result<HintIter> {
let mut p = ptr::null_mut();
let cnr = card.map(|c| c.get_index()).unwrap_or(-1) as c_int;
acheck!(snd_device_name_hint(cnr, iface.as_ptr(), &mut p))
.map(|_| HintIter(p, 0))
}
/// A constructor variant that takes the interface as a Rust string slice.
pub fn new_str(card: Option<&Card>, iface: &str) -> Result<HintIter> {
HintIter::new(card, &CString::new(iface).unwrap())
}
}
impl Iterator for HintIter {
type Item = Hint;
fn next(&mut self) -> Option<Hint> {
if self.0.is_null() { return None; }
let p = unsafe { *self.0.offset(self.1) };
if p.is_null() { return None; }
self.1 += 1;
Some(Hint::new(p))
}
}
/// [snd_device_name_get_hint](http://www.alsa-project.org/alsa-doc/alsa-lib/group___control.html) wrapper
#[derive(Debug, Clone)]
pub struct Hint {
pub name: Option<String>,
pub desc: Option<String>,
pub direction: Option<Direction>,
}
impl Hint {
fn get_str(p: *const c_void, name: &str) -> Option<String> {
let name = CString::new(name).unwrap();
let c = unsafe { alsa::snd_device_name_get_hint(p, name.as_ptr()) };
from_alloc("snd_device_name_get_hint", c).ok()
}
fn new(p: *const c_void) -> Hint {
let d = Hint::get_str(p, "IOID").and_then(|x| match &*x {
"Input" => Some(Direction::Capture),
"Output" => Some(Direction::Playback),
_ => None,
});
Hint { name: Hint::get_str(p, "NAME"), desc: Hint::get_str(p, "DESC"), direction: d }
}
}
#[test]
fn print_hints() {
for t in &["pcm", "ctl", "rawmidi", "timer", "seq", "hwdep"] {
println!("{} devices:", t);
let i = HintIter::new(None, &*CString::new(*t).unwrap()).unwrap();
for a in i { println!(" {:?}", a) }
}
}