termion/src/screen.rs

92 lines
2.4 KiB
Rust

//! Managing switching between main and alternate screen buffers.
//!
//! Note that this implementation uses xterm's new escape sequences for screen switching and thus
//! only works for xterm compatible terminals (which should be most terminals nowadays).
//!
//! # Example
//!
//! ```rust
//! use termion::screen::AlternateScreen;
//! use std::io::{Write, stdout};
//!
//! fn main() {
//! {
//! let mut screen = AlternateScreen::from(stdout());
//! write!(screen, "Writing to alternate screen!").unwrap();
//! screen.flush().unwrap();
//! }
//! println!("Writing to main screen.");
//! }
//! ```
use std::io::{self, Write};
use std::ops;
use std::fmt;
/// Switch to the main screen buffer of the terminal.
pub struct ToMainScreen;
impl fmt::Display for ToMainScreen {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, csi!("?1049l"))
}
}
/// Switch to the alternate screen buffer of the terminal.
pub struct ToAlternateScreen;
impl fmt::Display for ToAlternateScreen {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, csi!("?1049h"))
}
}
/// A terminal restorer, which wraps a type implementing Write, and causes all writes to be written
/// to an alternate screen.
///
/// This is achieved by switching the terminal to the alternate screen on creation and
/// automatically switching it back to the original screen on drop.
pub struct AlternateScreen<W: Write> {
/// The output target.
output: W,
}
impl<W: Write> AlternateScreen<W> {
/// Create an alternate screen wrapper struct for the provided output and switch the terminal
/// to the alternate screen.
pub fn from(mut output: W) -> Self {
write!(output, "{}", ToAlternateScreen).expect("switch to alternate screen");
AlternateScreen { output: output }
}
}
impl<W: Write> Drop for AlternateScreen<W> {
fn drop(&mut self) {
write!(self, "{}", ToMainScreen).expect("switch to main screen");
}
}
impl<W: Write> ops::Deref for AlternateScreen<W> {
type Target = W;
fn deref(&self) -> &W {
&self.output
}
}
impl<W: Write> ops::DerefMut for AlternateScreen<W> {
fn deref_mut(&mut self) -> &mut W {
&mut self.output
}
}
impl<W: Write> Write for AlternateScreen<W> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.output.write(buf)
}
fn flush(&mut self) -> io::Result<()> {
self.output.flush()
}
}