Revert use of alternate screen (#3648)

Cargo.lock

@@ -501,16 +501,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "ctrlc"
-version = "3.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b467862cc8610ca6fc9a1532d7777cee0804e678ab45410897b9396495994a0b"
-dependencies = [
- "nix",
- "windows-sys 0.52.0",
-]
-
 [[package]]
 name = "data-url"
 version = "0.3.1"
@@ -1406,17 +1396,6 @@ dependencies = [
  "tempfile",
 ]
 
-[[package]]
-name = "nix"
-version = "0.27.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2eb04e9c688eff1c89d72b407f168cf79bb9e867a9d3323ed6c01519eb9cc053"
-dependencies = [
- "bitflags 2.4.2",
- "cfg-if",
- "libc",
-]
-
 [[package]]
 name = "notify"
 version = "6.1.1"
@@ -2605,7 +2584,6 @@ dependencies = [
  "clap_mangen",
  "codespan-reporting",
  "comemo",
- "ctrlc",
  "dirs",
  "ecow",
  "env_proxy",

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