Struct Spinner 

pub struct Spinner { /* private fields */ }

Progress spinner for long-running CLI operations.

When stderr is a TTY, draws an animated spinner via indicatif, ticks in the background, and disables stdin echo to prevent keypress jank. When stderr is not a TTY, skips all indicatif machinery and falls back to plain stderr writes. Call finish with a completion message to replace it with a final line, or let it drop to remove it silently; Drop also restores echo and clears the bar so a panic or early ? propagation leaves the terminal in a usable state. Under panic = "abort", Drop does NOT run on a panic — the panic hook installed by install_spinner_termios_panic_hook restores termios instead, so the panic message renders cleanly before SIGABRT kills the process. Note: Drop also does NOT run on SIGINT/SIGTERM kill; if the spinner is interrupted mid-operation, run stty sane to restore echo.

Implementations

impl Spinner

pub fn start(msg: impl Into<Cow<'static, str>>) -> Self

Start a spinner with the given message (e.g. “Building kernel…”).

When stderr is not a TTY, no ProgressBar or ticker thread is created — all output methods fall back to plain eprintln!.

pub fn set_message(&self, msg: impl Into<Cow<'static, str>>)

Update the spinner message.

pub fn finish(self, msg: impl Into<Cow<'static, str>>)

Finish the spinner, replacing it with a completion message.

In non-TTY mode, prints the message to stderr directly.

pub fn println(&self, msg: impl AsRef<str>)

Print a line above the spinner. The spinner redraws below.

In non-TTY mode, prints directly to stderr.

pub fn suspend<F: FnOnce() -> R, R>(&self, f: F) -> R

Suspend the spinner tick, execute a closure, then resume. Use for terminal output that must not race with the spinner.

In non-TTY mode, calls f directly (no spinner to suspend).

pub fn with_progress<T, E, F>( start_msg: impl Into<Cow<'static, str>>, success_msg: impl Into<Cow<'static, str>>, f: F, ) -> Result<T, E>

where F: FnOnce(&Spinner) -> Result<T, E>,

Run f under a spinner that starts with start_msg, replaces itself with success_msg on Ok, and drops silently on Err so the error propagates without a stale progress bar obscuring the caller’s diagnostics. The closure receives the live &Spinner so it can call Self::println / Self::suspend / Self::set_message during the operation.

Trait Implementations

impl Drop for Spinner

fn drop(&mut self)

Restore terminal echo and clear any live progress bar on drop.

finish calls Self::teardown and takes self.pb via Option::take, so this impl is a no-op after an explicit end. When the spinner is dropped implicitly (panic, ? propagation, drop(sp), or scope exit), this restores the termios saved in Self::disable_echo and clears the live bar so stdin is usable afterwards.