This is in response to issue# d2aeb57, where the cursor is not shown when interrupting rad when a progress spinner thread is present.

This is mainly achieved by adding signal handling for spinners now using radicle-signals and crossbeam-channel. When a SIGINT signal fires off while a spinner is active, it will drop its respective HideCursor object and exit the process entirely.

Some other somewhat related changes to this patch:

• to better pass on handling to the OS/another CLI element, radicle-signals::uninstall() is implemented and used for the spinners.
  • the CLI pager also used radicle-signals, so that was also modified to use the above
• doc changes to the spinner/pager to include the tidbits on signal handling

No longer use ctrlc to handle interruption. Using radicle-signals + crossbeam_channel for that now. Implementation of this is working but may need some (significant) improvement.

Clean up

Adhere to “Radicle house style choice” + improve(?) errors for init_channels()

radicle-signals can now uninstall handlers now. - made spinner uninstall signal on any state of finish

Reason why I made that happen is because the pager also installs signal handlers and I didn’t want either to conflict.

I forgot to uninstall handlers for pagers so I’ll do that now

• Pagers now uninstall signal handlers when finished
• (un)init_channels() now actually returns io::Result<()>
• ran $ cargo fmt

remove CHANNEL static and (un)init_channel() functions.

• Don’t panic if we can’t install signal handlers, just keep spinning.
• also added sections to spinner_to()/page()’s comments on signal handling (spinner() kinda counts but its mostly meant to redirect to spinner_to()).

• _(un)install() iterates over a slice of signals (now const SIGNALS).

• use sig_rx.try_recv() rather than chan::select! for getting signals
• draw spinner as being cancelled before exiting
• change exit code to -1 rather than 0

Rebase.