How to react to actions like changing the current focused item or closing snap?

[leiserfg]

I'm thinking to add a colorscheme picker for snap but those are stoppers for me.
My plan with the current API is like

• Producer stores the current colorscheme and produces the list of known ones.
• A preview that changes the colorsheme to the one selected and shows something in the buffer (as it's required) like a line with several words highlighted using the termial_color_# (this is a workaround to the fact that there is not, as far as I know, how to react to focusing an item)
• If the user selects it we have nothing to do as the theme is already set.
• If the user cancels (ESC) we just have to bring back the old colorscheme (I don't know how to implement it properly or at least workaround it )

[camspiers]

Really interesting ideas, I will have to think about the API for this, because it's definitely doable.