Untidy exit on std::terminate()

[JoshCollins746]

If the process exits by std::terminate() after calling ScreenInteractive::Install(), the terminal is left in an untidy state. Specifically it appears to be because ScreenInteractive::Uninstall() is not run. The obvious symptom that I am facing is that when the process exits in this way, mouse events (such as moving the mouse on the terminal) cause cause a bunch of escape sequences to appear. However, there may well be other cleanup steps that cause other issues I am overlooking. My workaround at the moment is to issue reset to restore the terminal state.

I was able to reproduce this issue on Ubuntu 22.04 using xterm (echo $TERM -> xterm-256color) by adding a call to std::terminate() directly after a Loop is constructed, for example line 45 at https://github.com/ArthurSonzogni/FTXUI/blob/7b1f4d435bedecc49abc3f935bd97dc997a41977/examples/component/custom_loop.cpp

I narrowed down the mouse specific issue to failure to Reset() (at least one of) DECMode::kMouseVt200, DECMode::kMouseAnyEvent, DECMode::kMouseUrxvtMode and DECMode::kMouseSgrExtMode, and was able to fix it by installing a terminate handler at the top of main() and manually issuing the missing cleanup:

std::set_terminate([] {
  std::cout << "\x1b["
                "?"
                "1000"
                ";"
                "1003"
                ";"
                "1015"
                ";"
                "1006"
                "l"
            << '\0' << std::flush;
});

I hope this helps to reproduce and understand the issue, and that nicely handling std::terminate() is something you would be interested in addressing.

[ArthurSonzogni]

Thanks for reporting it!

FTXUI does handle SIGSTP signal to cleanup when terminating the app. This is for event outside of the app.
Here, std::terminate is called from inside the app. It is not supported.

I guess we could add support for it too.