ColorfulTheme's MultiSelect basically can't be used with an empty environment

[Ekleog]

For reasons that are yet unclear to me, ColorfulTheme becomes monochrome when being used with an empty environment (env -i [binary]).

This, in turn, makes its MultiSelect, that exclusively relies on colors to identify which items are selected, unusable.

Would it make sense to have ColorfulTheme automatically detect when it's being used in a way that will make colors not work, and have it fall back to SimpleTheme? If not, how would you suggest one to handle this scenario?

Anyway, thank you for indicatif and dialoguer, they're both awesome crates :)

[Ekleog]

Actually I found a bypass myself: using console::colors_enabled() to automatically dispatch between ColorfulTheme and SimpleTheme.

This being said… I wonder whether this should not be done upstream? If only so that people with screenreaders (who… hopefully can use the SimpleTheme? I'm not sure) could use programs made by people who didn't think of this case and just used ColorfulTheme without giving it a second thought.

[pksunkara]

The colors are switched on if a TTY is found. I am not exactly sure what happened with env -i [binary].

I think the best solution here is to edit the rendering of multi-select in ColorfulTheme.

[Ekleog]

I'd guess the reason why env -i makes coloring fail is because it loses the TERM variable and thus means that terminfo can't be found. As for auto-TTY-detection… I must say that I'm not sure it works? Using env -i does trigger my workaround based on console::colors_enabled() and generate a SimpleTheme, so I'd guess something that is not console::colors_enabled() is being used if there's already TTY detection supposed to happen.

This being said, your proposed solution does sound great to me too :)