terminal_io/
terminal.rs

1use duplex::Duplex;
2use std::io::{Read, Write};
3
4/// A trait for devices which may be connected to terminals.
5pub trait Terminal {}
6
7/// An extension trait for input streams connected to terminals.
8pub trait ReadTerminal: Read + Terminal {
9    /// Test whether the input is being sent a line at a time.
10    fn is_line_by_line(&self) -> bool;
11
12    /// Test whether the input is connected to a terminal.
13    ///
14    /// Also known as `isatty`.
15    fn is_input_terminal(&self) -> bool;
16}
17
18/// An extension trait for output streams connected to terminals.
19pub trait WriteTerminal: Write + Terminal {
20    /// Test whether color should be used on this terminal by default. This
21    /// includes both whether color is supported and whether the user has
22    /// not indicated a preference otherwise.
23    fn color_default(&self) -> bool {
24        self.color_support() != TerminalColorSupport::Monochrome && self.color_preference()
25    }
26
27    /// Test whether this output stream supports color control codes.
28    fn color_support(&self) -> TerminalColorSupport;
29
30    /// Test whether the user has indicated a preference for color output by
31    /// default. Respects the `NO_COLOR` environment variable where applicable.
32    fn color_preference(&self) -> bool;
33
34    /// Test whether the output is connected to a terminal.
35    ///
36    /// Also known as `isatty`.
37    fn is_output_terminal(&self) -> bool;
38}
39
40/// An extension trait for input/output streams connected to terminals.
41pub trait DuplexTerminal: ReadTerminal + WriteTerminal + Duplex {
42    /// Test whether both the input stream and output streams are connected to
43    /// terminals.
44    ///
45    /// Also known as `isatty`.
46    fn is_terminal(&self) -> bool {
47        self.is_input_terminal() && self.is_output_terminal()
48    }
49}
50
51/// Color support level, ranging from monochrome (color not supported) to
52/// 24-bit true color.
53#[derive(Copy, Clone, Debug, Eq, PartialEq)]
54pub enum TerminalColorSupport {
55    /// Color is not supported.
56    Monochrome,
57
58    /// Classic ANSI 8 colors. Sometimes extendable to 16 by using bold.
59    Classic8,
60
61    /// 256 colors with a "color cube". See [Wikipedia] for details.
62    ///
63    /// [Wikipedia]: https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit
64    ColorCube256,
65
66    /// 24-bit "true color" support. See [Wikipedia] for details.
67    ///
68    /// [Wikipedia]: https://en.wikipedia.org/wiki/ANSI_escape_code#24-bit
69    TrueColor,
70}
71
72impl Default for TerminalColorSupport {
73    #[inline]
74    fn default() -> Self {
75        Self::Monochrome
76    }
77}
terminal_io/terminal.rs

terminal_io/
terminal.rs
