Support white background terminals

[goerz]

This library assumes that it is being used in a dark background terminal.

It would be great to be able to use it in white background terminal:

• There seem to be many hard-code color values, for example, the name of the scheme being printed in white in the above screenshot, from here:

  Term.jl/src/theme.jl

  Lines 94 to 105 in 4ab195d

  	return print(
  	io,
  	Panel(
  	content;
  	width = 44,
  	justify = :center,
  	title = "Theme: {bold}$(theme.name){/bold}",
  	padding = (4, 4, 1, 1),
  	style = "#9bb3e0",
  	title_style = "white",
  	),
  	)

  Similarly, there are lots of hard-coded values in errors.jl and logs.jl, which unfortunately makes the otherwise very nice install_term_logger and install_term_stacktrace impossible to use. All of these colors should refer to something configurable in the color scheme

• There should be a switch to turn off all color, for monochrome or reduced-color terminals. The framed backtraces and such would be quite nice to have, but they should be rendered black on white (or white on black) in such environments

• It would be nice to have a built-in colorscheme that is tested for readability on white background terminals.

• The cherry on top would be to detect the background color of the terminal (e.g. via the COLORFGBG environment variable) and to choose the default scheme based on that.

[FedeClaudi]

Hey,

Thanks for opening this issue, it's a very good point.
I completely agree, all the hardcoded color values should be offloaded to the theme to allow complete customization.
Further, there should be a few pre-defined themes for light/dark and readability, as you suggest.

It seems like a fairly easy fix, perfect for someone that wants to actively contribute to Term 😄
Would you be interested in working on a PR?

[goerz]

Interested, yes 😀. Available, probably not (or at least I shouldn't).

Maybe I won't be able to help myself, so let's see. But if someone else wants to jump in, it would save me from the procrastination hole. 😉

[FedeClaudi]

Hahah, it seems like we're on the same boat here!

Let's leave it open and see who gives in first 😉

[FedeClaudi]

Fixed by #158