termion/
raw.rs

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1//! Managing raw mode.
2//!
3//! Raw mode is a particular state a TTY can have. It signifies that:
4//!
5//! 1. No line buffering (the input is given byte-by-byte).
6//! 2. The input is not written out, instead it has to be done manually by the programmer.
7//! 3. The output is not canonicalized (for example, `\n` means "go one line down", not "line
8//!    break").
9//!
10//! It is essential to design terminal programs.
11//!
12//! # Example
13//!
14//! ```rust,no_run
15//! use termion::raw::IntoRawMode;
16//! use std::io::{Write, stdout};
17//!
18//! fn main() {
19//!     let mut stdout = stdout().into_raw_mode().unwrap();
20//!
21//!     write!(stdout, "Hey there.").unwrap();
22//! }
23//! ```
24
25use std::io::{self, Write};
26use std::ops;
27
28use sys::Termios;
29use sys::attr::{get_terminal_attr, raw_terminal_attr, set_terminal_attr};
30
31/// The timeout of an escape code control sequence, in milliseconds.
32pub const CONTROL_SEQUENCE_TIMEOUT: u64 = 100;
33
34/// A terminal restorer, which keeps the previous state of the terminal, and restores it, when
35/// dropped.
36///
37/// Restoring will entirely bring back the old TTY state.
38pub struct RawTerminal<W: Write> {
39    prev_ios: Termios,
40    output: W,
41}
42
43impl<W: Write> Drop for RawTerminal<W> {
44    fn drop(&mut self) {
45        set_terminal_attr(&self.prev_ios).unwrap();
46    }
47}
48
49impl<W: Write> ops::Deref for RawTerminal<W> {
50    type Target = W;
51
52    fn deref(&self) -> &W {
53        &self.output
54    }
55}
56
57impl<W: Write> ops::DerefMut for RawTerminal<W> {
58    fn deref_mut(&mut self) -> &mut W {
59        &mut self.output
60    }
61}
62
63impl<W: Write> Write for RawTerminal<W> {
64    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
65        self.output.write(buf)
66    }
67
68    fn flush(&mut self) -> io::Result<()> {
69        self.output.flush()
70    }
71}
72
73/// Types which can be converted into "raw mode".
74///
75/// # Why is this type defined on writers and not readers?
76///
77/// TTYs has their state controlled by the writer, not the reader. You use the writer to clear the
78/// screen, move the cursor and so on, so naturally you use the writer to change the mode as well.
79pub trait IntoRawMode: Write + Sized {
80    /// Switch to raw mode.
81    ///
82    /// Raw mode means that stdin won't be printed (it will instead have to be written manually by
83    /// the program). Furthermore, the input isn't canonicalised or buffered (that is, you can
84    /// read from stdin one byte of a time). The output is neither modified in any way.
85    fn into_raw_mode(self) -> io::Result<RawTerminal<Self>>;
86}
87
88impl<W: Write> IntoRawMode for W {
89    fn into_raw_mode(self) -> io::Result<RawTerminal<W>> {
90        let mut ios = get_terminal_attr()?;
91        let prev_ios = ios;
92
93        raw_terminal_attr(&mut ios);
94
95        set_terminal_attr(&ios)?;
96
97        Ok(RawTerminal {
98            prev_ios: prev_ios,
99            output: self,
100        })
101    }
102}
103
104impl<W: Write> RawTerminal<W> {
105    pub fn suspend_raw_mode(&self) -> io::Result<()> {
106        set_terminal_attr(&self.prev_ios)?;
107        Ok(())
108    }
109
110    pub fn activate_raw_mode(&self) -> io::Result<()> {
111        let mut ios = get_terminal_attr()?;
112        raw_terminal_attr(&mut ios);
113        set_terminal_attr(&ios)?;
114        Ok(())
115    }
116}
117
118#[cfg(test)]
119mod test {
120    use super::*;
121    use std::io::{Write, stdout};
122
123    #[test]
124    fn test_into_raw_mode() {
125        let mut out = stdout().into_raw_mode().unwrap();
126
127        out.write_all(b"this is a test, muahhahahah\r\n").unwrap();
128
129        drop(out);
130    }
131}
termion/raw.rs

termion/
raw.rs
