Files
neutuino/src/unix.rs
2025-06-23 04:02:45 -04:00

334 lines
9.1 KiB
Rust

use std::ffi::{c_int, c_uint, c_ulong, c_ushort};
use std::io;
use std::sync::LazyLock;
use crate::input::{Event, Key, KeyModifiers, KeyType};
use std::ffi::{c_short, c_void};
use std::time::Duration;
unsafe extern "C" {
fn ioctl(fd: c_int, request: c_ulong, argp: *mut u8) -> c_int;
fn cfmakeraw(termios: *mut Termios);
fn tcgetattr(fd: c_int, termios: *mut Termios) -> c_int;
fn tcsetattr(fd: c_int, optional_actions: c_int, termios: *mut Termios) -> c_int;
}
const STDIN_FILENO: c_int = 0;
const STDOUT_FILENO: c_int = 1;
const POLLIN: c_short = 1;
#[cfg(not(target_os = "macos"))]
const TIOCGWINSZ: c_ulong = 0x5413;
#[cfg(not(target_os = "macos"))]
const NCCS: usize = 0x20;
#[cfg(target_os = "macos")]
const TIOCGWINSZ: c_ulong = 0x4008_7468;
#[cfg(target_os = "macos")]
const NCCS: usize = 0x14;
#[repr(C)]
#[derive(Default, Debug, Clone, Copy)]
struct Winsize {
row: c_ushort,
col: c_ushort,
xpixel: c_ushort,
ypixel: c_ushort,
}
#[repr(C)]
#[derive(Default, Debug, Clone, Copy)]
struct Termios {
iflag: c_uint,
oflag: c_uint,
cflag: c_uint,
lflag: c_uint,
cc: [u8; NCCS],
}
fn get_attributes(fd: c_int, termios: &mut Termios) -> io::Result<()> {
if unsafe { tcgetattr(fd, &raw mut *termios) } != 0 {
return Err(io::Error::last_os_error());
}
Ok(())
}
fn set_attributes(fd: c_int, termios: &mut Termios) -> io::Result<()> {
if unsafe { tcsetattr(fd, 0, std::ptr::from_mut(termios)) } != 0 {
return Err(io::Error::last_os_error());
}
Ok(())
}
static TERMIOS: LazyLock<Option<Termios>> = LazyLock::new(|| {
let mut orig_termios = Termios::default();
get_attributes(STDIN_FILENO, &mut orig_termios).ok()?;
Some(orig_termios)
});
/// Enables raw mode, which disables line buffering, input echoing, and output canonicalization
///
/// # Errors
///
/// If there is no stdin,
/// stdin is not a tty,
/// or it fails to change terminal settings
pub fn enable_raw_mode() -> io::Result<()> {
let mut termios = (*TERMIOS).ok_or(io::Error::other("Failed to get terminal properties"))?;
unsafe {
cfmakeraw(&mut termios);
}
set_attributes(STDIN_FILENO, &mut termios)?;
Ok(())
}
/// Disables raw mode, which enables line buffering, input echoing, and output canonicalization
///
/// # Errors
///
/// If there is no stdin,
/// stdin is not a tty,
/// or it fails to change terminal settings
pub fn disable_raw_mode() -> io::Result<()> {
let mut termios = (*TERMIOS).ok_or(io::Error::other("Failed to get terminal properties"))?;
set_attributes(STDIN_FILENO, &mut termios)?;
Ok(())
}
/// Enables ANSI support on Windows terminals
///
/// ANSI is on by default on *nix machines but still exists on them for simpler usage
///
/// # Errors
///
/// Never on *nix
///
/// If There is no stdout,
/// if stdout isn't a TTY, or
/// if it cannot change terminal properties on Windows
#[cfg(unix)]
pub fn enable_ansi() -> io::Result<()> {
// ANSI is on by default on unix platforms
// This is here for compatibility with the windows version of this API
Ok(())
}
/// Gets the size of the terminal
///
/// Returns in (width, height) format
///
/// # Errors
///
/// If there is no stdout,
/// if stdout isn't a TTY, or
/// if it fails to retrieve the terminal size
pub fn get_terminal_size() -> io::Result<(u16, u16)> {
let mut winsize = Winsize::default();
let ioctl_result = unsafe { ioctl(STDOUT_FILENO, TIOCGWINSZ, (&raw mut winsize).cast::<u8>()) };
if ioctl_result == 0 {
Ok((winsize.col, winsize.row))
} else {
Err(io::Error::last_os_error())
}
}
unsafe extern "C" {
fn poll(fds: *mut PollFD, nfds: c_ulong, timeout: c_int) -> c_int;
fn read(fd: c_int, buf: *mut c_void, count: c_ulong) -> c_short;
}
#[repr(C)]
#[derive(Debug, Clone, Copy)]
struct PollFD {
fd: c_int,
events: c_short,
revents: c_short,
}
struct ReadIterator {
fd: c_int,
buf: u8,
}
impl ReadIterator {
fn new(fd: c_int) -> Self {
Self { fd, buf: 0 }
}
}
impl Iterator for ReadIterator {
type Item = io::Result<u8>;
fn next(&mut self) -> Option<Self::Item> {
let bytes_read = unsafe { read(self.fd, (&raw mut self.buf).cast::<c_void>(), 1) };
match bytes_read {
1.. => Some(Ok(self.buf)),
0 => None,
_ => Some(Err(io::Error::last_os_error())),
}
}
}
/// Attempts to fetch input from stdin
///
/// # Errors
/// If the timeout has expired or
/// there was an error getting the data
pub fn poll_input(timeout: Duration) -> io::Result<Event> {
let mut fds = [PollFD {
fd: STDIN_FILENO,
events: POLLIN,
revents: 0,
}];
let result = unsafe {
#[allow(clippy::cast_possible_truncation)]
poll(
fds.as_mut_ptr(),
fds.len() as c_ulong,
timeout.as_millis() as c_int,
)
};
let mut read_iter = ReadIterator::new(STDIN_FILENO);
let timed_out: io::Error = io::ErrorKind::TimedOut.into();
match result {
1.. => {
let item = read_iter.next().ok_or(timed_out)??;
try_parse_event(item, &mut read_iter)
}
0 => Err(timed_out),
_ => Err(io::Error::last_os_error()),
}
}
fn try_parse_event<I>(item: u8, iter: &mut I) -> io::Result<Event>
where
I: Iterator<Item = io::Result<u8>>,
{
match item {
b'\x1b' => try_parse_ansi_sequence(iter),
b'\r' => Ok(Event::Key(
Key::Char('\n'),
KeyType::Press,
KeyModifiers::none(),
)),
b'\n' => Ok(Event::Key(
Key::Char('j'),
KeyType::Press,
KeyModifiers::none().ctrl(),
)),
b'\t' => Ok(Event::Key(
Key::Char('\t'),
KeyType::Press,
KeyModifiers::none(),
)),
b'\x7f' => Ok(Event::Key(
Key::Backspace,
KeyType::Press,
KeyModifiers::none(),
)),
b'\0' => Ok(Event::Key(Key::Null, KeyType::Press, KeyModifiers::none())),
c @ b'\x01'..=b'\x1a' => Ok(Event::Key(
Key::Char((c + 96) as char),
KeyType::Press,
KeyModifiers::none().ctrl(),
)),
c @ b'\x1c'..=b'\x1f' => Ok(Event::Key(
Key::Char((c + 24) as char),
KeyType::Press,
KeyModifiers::none().ctrl(),
)),
c => {
let character = parse_utf8_char(c, iter)?;
Ok(Event::Key(
Key::Char(parse_utf8_char(c, iter)?),
KeyType::Press,
KeyModifiers {
shift: character.is_uppercase(),
alt: false,
ctrl: false,
meta: false,
},
))
}
}
}
fn parse_utf8_char<I>(c: u8, iter: &mut I) -> io::Result<char>
where
I: Iterator<Item = io::Result<u8>>,
{
let error = || io::Error::new(io::ErrorKind::InvalidData, "Input char is not valid UTF-8");
let mut bytes = vec![c];
for _ in 1..=4 {
if let Ok(string) = std::str::from_utf8(&bytes) {
return Ok(string.chars().next().unwrap());
}
bytes.push(iter.next().ok_or_else(error)??);
}
Err(error())
}
fn try_parse_ansi_sequence<I>(iter: &mut I) -> io::Result<Event>
where
I: Iterator<Item = io::Result<u8>>,
{
let error = io::Error::other("Could not parse event");
match iter.next() {
Some(Ok(b'O')) => match iter.next() {
Some(Ok(val @ b'P'..=b's')) => Ok(Event::Key(
Key::F(1 + val - b'P'),
KeyType::Press,
KeyModifiers::none(),
)),
_ => Err(error),
},
Some(Ok(b'[')) => try_parse_csi_sequence(iter).ok_or(error),
_ => Err(error),
}
}
fn try_parse_csi_sequence<I>(iter: &mut I) -> Option<Event>
where
I: Iterator<Item = io::Result<u8>>,
{
match iter.next() {
Some(Ok(b'[')) => match iter.next() {
Some(Ok(val @ b'A'..=b'E')) => Some(Event::Key(
Key::F(1 + val - b'A'),
KeyType::Press,
KeyModifiers::none(),
)),
_ => None,
},
Some(Ok(b'D')) => Some(Event::Key(Key::Left, KeyType::Press, KeyModifiers::none())),
Some(Ok(b'C')) => Some(Event::Key(Key::Right, KeyType::Press, KeyModifiers::none())),
Some(Ok(b'A')) => Some(Event::Key(Key::Up, KeyType::Press, KeyModifiers::none())),
Some(Ok(b'B')) => Some(Event::Key(Key::Down, KeyType::Press, KeyModifiers::none())),
Some(Ok(b'H')) => Some(Event::Key(Key::Home, KeyType::Press, KeyModifiers::none())),
Some(Ok(b'F')) => Some(Event::Key(Key::End, KeyType::Press, KeyModifiers::none())),
Some(Ok(b'Z')) => Some(Event::Key(
Key::Tab,
KeyType::Press,
KeyModifiers::none().shift(),
)),
_ => None,
}
}
#[test]
fn test_parse_utf8() {
let string = "abcéŷ¤£€ù%323";
let ref mut bytes = string.bytes().map(|x| Ok(x));
let chars = string.chars();
for c in chars {
let b = bytes.next().unwrap().unwrap();
let character = parse_utf8_char(b, bytes).unwrap();
assert!(c == character);
}
}