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WIP Return Escape immediately after one press
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@atanunq
atanunq committed Oct 7, 2020
1 parent 0da89c5 commit c8ea46f
Showing 1 changed file with 163 additions and 65 deletions.
228 changes: 163 additions & 65 deletions src/unix_term.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -80,6 +80,60 @@ pub fn read_secure() -> io::Result<String> {
})
}

fn read_single_byte(fd: i32) -> io::Result<Option<u8>> {
let mut readfds = core::mem::MaybeUninit::uninit();
unsafe {
libc::FD_SET(fd, readfds.as_mut_ptr());
};
let mut readfds = unsafe { readfds.assume_init() };

// zero timeout, i.e check if there is something to be read right now
let mut timeout = libc::timeval {
tv_sec: 0,
tv_usec: 0,
};

let ret = unsafe {
libc::select(
fd + 1,
&mut readfds as *mut _,
std::ptr::null_mut(),
std::ptr::null_mut(),
&mut timeout,
)
};
if ret < 0 {
return Err(io::Error::last_os_error());
}

let is_ready = unsafe { libc::FD_ISSET(fd, &mut readfds as *mut _) };

if is_ready {
//there is something to be read

// let mut buf: [u8; 1] = [0];
// let read = unsafe { libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 1) };

//read only 1 byte
let mut byte: u8 = 0;
let read = unsafe { libc::read(fd, &mut byte as *mut u8 as _, 1) };

if read < 0 {
Err(io::Error::last_os_error())
} else if byte == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
} else {
Ok(Some(byte))
}
} else {
//there is nothing to be read
Ok(None)
}
}

pub fn read_single_key() -> io::Result<Key> {
let tty_f;
let fd = unsafe {
Expand All @@ -92,74 +146,118 @@ pub fn read_single_key() -> io::Result<Key> {
};
let mut buf = [0u8; 20];
let mut termios = core::mem::MaybeUninit::uninit();
c_result(|| unsafe { libc::tcgetattr(fd, termios.as_mut_ptr()) })?;
c_result(|| unsafe { libc::tcgetattr(fd, termios.as_mut_ptr()) })?;
let mut termios = unsafe { termios.assume_init() };
let original = termios;
unsafe { libc::cfmakeraw(&mut termios) };
c_result(|| unsafe { libc::tcsetattr(fd, libc::TCSADRAIN, &termios) })?;
let rv = unsafe {
let read = libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 1);
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[0] == b'\x1b' {
// read 19 more bytes if the first byte was the ESC code
let read = libc::read(fd, buf[1..].as_mut_ptr() as *mut libc::c_void, 19);
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[1] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
} else {
Ok(key_from_escape_codes(&buf[..(read + 1) as usize]))
}
} else if buf[0] & 224u8 == 192u8 {
// a two byte unicode character
let read = libc::read(fd, buf[1..].as_mut_ptr() as *mut libc::c_void, 1);
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[1] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))

let byte = read_single_byte(fd)?;
let rv = match byte {
Some(b'\x1b') => {
// Escape was read, keep reading in case we find a familiar key
if let Some(b1) = read_single_byte(fd)? {
if b1 == b'[' {
if let Some(b2) = read_single_byte(fd)? {
match b2 {
b'A' => Ok(Key::ArrowUp),
b'B' => Ok(Key::ArrowDown),
b'C' => Ok(Key::ArrowRight),
b'D' => Ok(Key::ArrowLeft),
b'H' => Ok(Key::Home),
b'F' => Ok(Key::End),
b'3' => {
if let Some(b'~') = read_single_byte(fd)? {
Ok(Key::Del)
} else {
Ok(Key::Escape)
}
}
_ => Ok(Key::Escape),
}
} else {
// \x1b[ and no more input
Ok(Key::Escape)
}
} else {
// char after escape is not [
Ok(Key::Escape)
}
} else {
Ok(key_from_escape_codes(&buf[..2 as usize]))
//nothing after escape
Ok(Key::Escape)
}
} else if buf[0] & 240u8 == 224u8 {
// a three byte unicode character
let read = libc::read(fd, buf[1..].as_mut_ptr() as *mut libc::c_void, 2);
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[1] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
}
Some(byte) => {
buf[0] = byte;
if byte & 224u8 == 192u8 {
// a two byte unicode character
let read = unsafe { libc::read(fd, buf[1..].as_mut_ptr() as *mut libc::c_void, 1) };
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[1] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
} else {
Ok(key_from_escape_codes(&buf[..2 as usize]))
}
} else if byte & 240u8 == 224u8 {
// a three byte unicode character
let read = unsafe { libc::read(fd, buf[1..].as_mut_ptr() as *mut libc::c_void, 2) };
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[1] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
} else {
Ok(key_from_escape_codes(&buf[..3 as usize]))
}
} else if byte & 248u8 == 240u8 {
// a four byte unicode character
let read = unsafe { libc::read(fd, buf[1..].as_mut_ptr() as *mut libc::c_void, 3) };
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[1] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
} else {
Ok(key_from_escape_codes(&buf[..4 as usize]))
}
} else {
Ok(key_from_escape_codes(&buf[..3 as usize]))
Ok(key_from_escape_codes(&[byte]))
}
} else if buf[0] & 248u8 == 240u8 {
// a four byte unicode character
let read = libc::read(fd, buf[1..].as_mut_ptr() as *mut libc::c_void, 3);
if read < 0 {
Err(io::Error::last_os_error())
} else if buf[1] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
} else {
Ok(key_from_escape_codes(&buf[..4 as usize]))
}
None => {
//there is no subsequent byte ready to be read, block and wait for input

let mut readfds = core::mem::MaybeUninit::uninit();
unsafe {
libc::FD_SET(fd, readfds.as_mut_ptr());
};
let mut readfds = unsafe { readfds.assume_init() };

// block until there is something to be read
let ret = unsafe {
libc::select(
fd + 1,
&mut readfds as *mut _,
std::ptr::null_mut(),
std::ptr::null_mut(),
// null timeout pointer means that it will block indefinitely
std::ptr::null_mut(),
)
};
if ret < 0 {
return Err(io::Error::last_os_error());
}
} else if buf[0] == b'\x03' {
Err(io::Error::new(
io::ErrorKind::Interrupted,
"read interrupted",
))
} else {
Ok(key_from_escape_codes(&buf[..read as usize]))

read_single_key()
}
};
c_result(|| unsafe { libc::tcsetattr(fd, libc::TCSADRAIN, &original) })?;
Expand All @@ -178,17 +276,17 @@ pub fn read_single_key() -> io::Result<Key> {

pub fn key_from_escape_codes(buf: &[u8]) -> Key {
match buf {
b"\x1b[D" => Key::ArrowLeft,
b"\x1b[C" => Key::ArrowRight,
b"\x1b" => Key::Escape,
b"\x1b[A" => Key::ArrowUp,
b"\x1b[B" => Key::ArrowDown,
b"\n" | b"\r" => Key::Enter,
b"\x1b" => Key::Escape,
b"\x7f" => Key::Backspace,
b"\x1b[C" => Key::ArrowRight,
b"\x1b[D" => Key::ArrowLeft,
b"\x1b[H" => Key::Home,
b"\x1b[F" => Key::End,
b"\t" => Key::Tab,
b"\x1b[3~" => Key::Del,
b"\n" | b"\r" => Key::Enter,
b"\x7f" => Key::Backspace,
b"\t" => Key::Tab,
buf => {
if let Ok(s) = str::from_utf8(buf) {
if let Some(c) = s.chars().next() {
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