xed: Default gtksourceview style doesn't work well with dark themes

[Jeremy7701]

/usr/share/nemo/actions/sample.nemo_action is unreadable, at least in dark mode since most of the text is pale blue on black.

I suggest all colour coding is removed.

Part example:-

[mtwebster]

This Xed's default theme color for comments in many (most?) file formats. It's not specific to nemo action files. Select a different theme in Xed's preferences as a workaround for now. I'm not sure we can modify these themes, depending on what package provides them.

[Jeremy7701]

There is a solution : Xed allows you to choose a theme from its Edit -> preferences.
The 'Kate' theme looks quite good on a dark screen.
Sorry if I misinterpreted your use of the word "theme" !

[clefebvre]

I wonder if we could provide a light gtksourceview theme, and default to it. The one we default to right now, isn't always light, it's made for light, but doesn't hardcode the background color..

[clefebvre]

For the line numbers there's a regression between 21.x and 22:

They went from a relative rgba shade to a hardcoded color.

[clefebvre]

It comes from this commit upstream: https://gitlab.gnome.org/GNOME/gtksourceview/-/commit/7942b41c7929a86bf81a4f0bddbf11f6de8d82ef

[clefebvre]

Reverting this and switching the comments to grey gives a good result in both light and dark scenarios.

[clefebvre]

Fixed in xed 3.6.4 (with new default "Xed" style chosen).