Revert use of alternate screen

The alternate screen doesn't support scrolling by default. A more comprehensive alternate screen solution could support it, but adding something so complex immediately before the release is a bit risky.

Fixes #3613

crates/typst-cli/Cargo.toml

@@ -31,7 +31,6 @@ chrono = { workspace = true }
 clap = { workspace = true }
 codespan-reporting = { workspace = true }
 comemo = { workspace = true }
-ctrlc = { workspace = true }
 dirs = { workspace = true }
 ecow = { workspace = true }
 env_proxy = { workspace = true }

crates/typst-cli/src/main.rs

@@ -19,7 +19,6 @@ use std::process::ExitCode;
 use clap::Parser;
 use codespan_reporting::term;
 use codespan_reporting::term::termcolor::WriteColor;
-use ecow::eco_format;
 use once_cell::sync::Lazy;
 
 use crate::args::{CliArguments, Command};
@@ -46,13 +45,7 @@ fn main() -> ExitCode {
  Command::Update(command) => crate::update::update(command),
  };
 
- // Leave the alternate screen if it was opened. This operation is done here
- // so that it is executed prior to printing the final error.
- let res_leave = terminal::out()
- .leave_alternate_screen()
- .map_err(|err| eco_format!("failed to leave alternate screen ({err})"));
-
- if let Some(msg) = res.err().or(res_leave.err()) {
+ if let Err(msg) = res {
  set_failed();
  print_error(&msg).expect("failed to print error");
  }

crates/typst-cli/src/terminal.rs

@@ -1,11 +1,8 @@
 use std::io::{self, IsTerminal, Write};
-use std::sync::atomic::{AtomicBool, Ordering};
 
 use codespan_reporting::term::termcolor;
-use ecow::eco_format;
 use once_cell::sync::Lazy;
 use termcolor::{ColorChoice, WriteColor};
-use typst::diag::StrResult;
 
 use crate::ARGS;
 
@@ -18,7 +15,6 @@ pub fn out() -> TermOut {
 /// The stuff that has to be shared between instances of [`TermOut`].
 struct TermOutInner {
  stream: termcolor::StandardStream,
- in_alternate_screen: AtomicBool,
 }
 
 impl TermOutInner {
@@ -32,10 +28,7 @@ impl TermOutInner {
  };
 
  let stream = termcolor::StandardStream::stderr(color_choice);
- TermOutInner {
- stream,
- in_alternate_screen: AtomicBool::new(false),
- }
+ TermOutInner { stream }
  }
 }
 
@@ -48,24 +41,6 @@ pub struct TermOut {
 }
 
 impl TermOut {
- /// Initialize a handler that listens for Ctrl-C signals.
- /// This is used to exit the alternate screen that might have been opened.
- pub fn init_exit_handler(&mut self) -> StrResult<()> {
- // We can safely ignore the error as the only thing this handler would do
- // is leave an alternate screen if none was opened; not very important.
- let mut term_out = self.clone();
- ctrlc::set_handler(move || {
- let _ = term_out.leave_alternate_screen();
-
- // Exit with the exit code standard for Ctrl-C exits[^1].
- // There doesn't seem to be another standard exit code for Windows,
- // so we just use the same one there.
- // [^1]: https://tldp.org/LDP/abs/html/exitcodes.html
- std::process::exit(128 + 2);
- })
- .map_err(|err| eco_format!("failed to initialize exit handler ({err})"))
- }
-
  /// Clears the entire screen.
  pub fn clear_screen(&mut self) -> io::Result<()> {
  // We don't want to clear anything that is not a TTY.
@@ -90,32 +65,6 @@ impl TermOut {
  }
  Ok(())
  }
-
- /// Enters the alternate screen if none was opened already.
- pub fn enter_alternate_screen(&mut self) -> io::Result<()> {
- if self.inner.stream.supports_color()
- && !self.inner.in_alternate_screen.load(Ordering::Acquire)
- {
- let mut stream = self.inner.stream.lock();
- write!(stream, "\x1B[?1049h")?;
- stream.flush()?;
- self.inner.in_alternate_screen.store(true, Ordering::Release);
- }
- Ok(())
- }
-
- /// Leaves the alternate screen if it is already open.
- pub fn leave_alternate_screen(&mut self) -> io::Result<()> {
- if self.inner.stream.supports_color()
- && self.inner.in_alternate_screen.load(Ordering::Acquire)
- {
- let mut stream = self.inner.stream.lock();
- write!(stream, "\x1B[?1049l")?;
- stream.flush()?;
- self.inner.in_alternate_screen.store(false, Ordering::Release);
- }
- Ok(())
- }
 }
 
 impl Write for TermOut {

crates/typst-cli/src/watch.rs

@@ -20,12 +20,6 @@ use crate::{print_error, terminal};
 
 /// Execute a watching compilation command.
 pub fn watch(mut timer: Timer, mut command: CompileCommand) -> StrResult<()> {
- // Enter the alternate screen and handle Ctrl-C ourselves.
- terminal::out().init_exit_handler()?;
- terminal::out()
- .enter_alternate_screen()
- .map_err(|err| eco_format!("failed to enter alternate screen ({err})"))?;
-
  // Create a file system watcher.
  let mut watcher = Watcher::new(command.output())?;
 

docs/changelog.md

@@ -243,8 +243,6 @@ description: |
 - Command line interface
  - Added support for passing [inputs]($category/foundations/sys) via a CLI flag
  - When passing the filename `-`, Typst will now read input from stdin
- - The watch mode now uses the alternate screen so that the original state of
- the terminal is restored when exiting
  - Now uses the system-native TLS implementation for network fetching which
  should be generally more robust
  - Watch mode will now properly detect when a previously missing file is