syntax_theme_file: preview code with a syntect .tmTheme file - #1227

Stop there and read CONTRIBUTING.md

Your Claude should have alerted you at when reading the AGENTS.md file

Hi @Canop apologies I missed that. I do obviously use Claude etc in my day-to-day. I've also looked at https://dystroy.org/blog/contributing/ and understand the burden excessive PR volume/noise can make.

While I believe this PR is well scoped, I'll understand if you want to close it out.

This PR is well scoped. Just like what your previous one, which is why I didn't react immediately.

But this isn't a job task, I'm not payed to review Claude contributions on my FOSS programs. So I ask people to at least write the text of issues and PR themselves, having made the effort to completely understand the problem.

I don't think I'll close this one but I'd like people to take such project like an opportunity to use their brain to build things and overcome difficulties, which becomes harder and harder at work.

Taken as it, there would be some disappointment as ansi or base16 colors of bat wouldn't work because they use RGBA colors with an alpha to 00 or 01 (as in #318).

So I suggest this PR also changes Region::from_syntect in text_view.rs to handle such colors, eg

pub fn from_syntect(region: &(Style, &str)) -> Self {
    let c = region.0.foreground;
    let fg = match c.a {
        0 => Some(Color::AnsiValue(c.r)),
        1 => None,
        _ => Some(Color::Rgb { r: c.r, g: c.g, b: c.b }),
    };
    ...
}

I would also ensure it's possible to unset this, and that a later theme preference isn't overriden by a previous theme_file one.

Thanks, all done:

• bat's ansi and base16 themes: Region::from_syntect now reads the alpha byte the way you suggested.
• Unsetting: syntax_theme_file: "" clears a value set by an earlier conf file. Setting syntax_theme in a later file also replaces it, and the later setting wins.

Note that with the default setup, the skin's syntax_theme: MochaDark now beats a syntax_theme_file set in conf.hjson. The docs suggest putting syntax_theme_file in the skin file your conf.hjson imports (e.g. skins/dark-blue.hjson).