[UX] Prevent white lines on (almost) white background

[HansCronau]

Hi there. I hope to contribute to the project with some feedback on the UI: I have a hard time seeing the white connection lines for trains. I'm unfamiliar with the method used for the colouring of the connections, but it does not appear to prevent colours with high similarity to the application's background, which is also (almost) white. Since trains are always white for me (NL) this is a recurring challenge.

[grote]

Line colors are coming from the data source which should use official colors.

[HansCronau]

Hi @grote! Thanks for explaining.

Do you mean 'should' as in:
"The source should use official colours (though maybe it doesn't)"?

In that case I guess the question would be: how would one find a balance between using official colours and keeping them visible on a white background?

[grote]

I guess some data sources use official colors and others don't. I can't travel and investigate this everywhere. A solution could be to add a dark stroke color around the white lines when the user uses the light theme and a bright color when the user uses the dark theme and has dark line colors.

Feel free to do a PR for the stroke solution.

[Altonss]

I implemented a fix for this in #948. In short, these are the things I changed to fix this issue:

• Invert line background color if contrast isn't high enough. (This might lead to some mismatch with some official colors, but it's not that commom, and I'd say it is a good compromise :) )
• Don't use the foreground color provided by line, simple choose the best between white and black for best readability :)

Feel free to give your feedback about it :)

[Altonss]

I'm looking for feedback on the UI changes in #948, if someone is willing to try it out and review the changes it would be great :) I don't feel comfortable merging a big UI change without feedback :)