Allow to customize float window appearance e.g. of the doctor

[lervag]

Describe the feature

The doctor float window is created here:

https://github.com/scalameta/nvim-metals/blob/6065608a98a6add79886ad8ab6d2f2619cff8a09/lua/metals/doctor.lua#L164-L175

It has hardcoded parameters for creating the window and relies on plenary. I would be very happy if this could be more customizeable. I.e., I would want to do something like this to specify configuration:

require("metals").setup {
  floats = {
    window_options = {
      width = 0.9,
      height = 0.9,
      title_pos = "left",
    },
    border = {
      style = "double",
    },
  },
}

where window_options and border have are similar to the options for the builtin nvim_open_win.

Perhaps it would make sense to rely on Popup from nui.nvim instead of plenary here? It provides something that is more in line with nvim_open_win and that it may be easier to customize; possibly.

Potential ways to implement

I could possibly help with implementing this, but I would need some guidance and I think it should be done for more than just the doctor. That is, I would want to allow custom configuration for all the floating windows similar to the doctor using the same mechanism.

[ckipp01]

Thanks for opening this up @lervag. I can understand why someone may want a bit more control here.

Perhaps it would make sense to rely on Popup from nui.nvim instead of plenary here?

I don't think I really want to switch at this time. I use Plenary for a couple other modules throughout nvim-metals, like Path, etc, so it's not as easy to swap it out, even if I wanted to. I also wouldn't want to require another dependency.

Let me think on this a bit and I'll see if I can come up with a direction I feel comfortable with that would allow something like this. It's also worth being said that I've purposefully kept configuration in nvim-metals very minimal just to make maintenance easier, so I also want to be a bit careful here.

[lervag]

Perhaps it would make sense to rely on Popup from nui.nvim instead of plenary here?

I don't think I really want to switch at this time. I use Plenary for a couple other modules throughout nvim-metals, like Path, etc, so it's not as easy to swap it out, even if I wanted to. I also wouldn't want to require another dependency.

Ok, that's fine and understandable.

Let me think on this a bit and I'll see if I can come up with a direction I feel comfortable with that would allow something like this.

Cool!

It's also worth being said that I've purposefully kept configuration in nvim-metals very minimal just to make maintenance easier, so I also want to be a bit careful here.

Yes, I like that idea personally. But on this specific topic, I think there is a reason to allow more flexibility. I've tried to make all my floating windows have a consistent style. I believe for everyone who wants to do that, we actually need a way to provide this configuration. Of course, we will use sensible defaults that many people will be fine with.