Question about making Lem extensions/packages: Front/Backend

[gggion]

When adding functionality to certain UI elements, do I need to add frontend specific code to target ncurses, webview, etc?
I've read: Display Concepts and #1311 (comment)

[cianoc]

It really depends upon the changes. What are you trying to do?

[gggion]

Don't have a specific thing in mind but for the sake of the argument lets say I want to add a 'slideshow' window, in which I cycle through images on path using a configurable timer that can be increased/decreased to manipulate speed, and I wanted to also be able to manipulate the opacity of the images when they're being displayed.

If this was the case , I could use imagemagick to manipulate the opacity, but I could probably also use css/js if in webview.
My question then would be what would happen if I were to then use ncurses or sdl2. Would my package work exclusively with webview? would it break my config when trying to use ncurses/sdl2? Would I need to add safeguards in my code to check for features before enabling the package?

Sorry if this is too meandering, I'm trying to wrap my head around designing things in this backend/frontend dichotomy, I could probably try things out but I'm not familiar enough with webview yet.

[cianoc]

Gotcha.

I don't know enough about this to give good advice, but I'd suggest start off by looking at how the SDL2 (which is being deprecated), curses and webview fronts are handled using generics.

Generally you're going to want as little implementation specific code as possible, and to have a clean interface to it.

Alternatively you could write a package that only works for webview, and then make sure that if its loaded in ncurses it doesn't break anything.