feat: add NormalFloat hl for floating windows

[jamestansx]

Currently, NvimTreeNormal is used for floating window's background. However, when winblend is set and Normal highlight is set to transparent, the background will turn black. Using NormalFloat allows users to customize the background and not interfere with normal window.

minimal init.lua

vim.g.loaded_netrw = 1
vim.g.loaded_netrwPlugin = 1

vim.cmd [[set runtimepath=$VIMRUNTIME]]
vim.cmd [[set packpath=/tmp/nvt-min/site]]
local package_root = "/tmp/nvt-min/site/pack"
local install_path = package_root .. "/packer/start/packer.nvim"
local function load_plugins()
  require("packer").startup {
    {
      "wbthomason/packer.nvim",
      --"jamestansx/nvim-tree.lua",
      "nvim-tree/nvim-tree.lua",
      "nvim-tree/nvim-web-devicons",
      { "catppuccin/nvim", as = "catppuccin" }
      -- ADD PLUGINS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
    },
    config = {
      package_root = package_root,
      compile_path = install_path .. "/plugin/packer_compiled.lua",
      display = { non_interactive = true },
    },
  }
end
if vim.fn.isdirectory(install_path) == 0 then
  print "Installing nvim-tree and dependencies."
  vim.fn.system { "git", "clone", "--depth=1", "https://github.com/wbthomason/packer.nvim", install_path }
end
load_plugins()
require("packer").sync()
vim.cmd [[autocmd User PackerComplete ++once echo "Ready!" | lua setup()]]
vim.opt.termguicolors = true
vim.opt.cursorline = true
vim.opt.winblend = 10

-- MODIFY NVIM-TREE SETTINGS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
---@diagnostic disable-next-line: duplicate-set-field
_G.setup = function()
  -- run help with `g?` key or enable float
  -- to see the background color in black
  require("nvim-tree").setup {}

  require("catppuccin").setup({
    transparent_background = true, -- to set Normal to transparent
    integrations = {
      nvimtree = false, -- to ensure that no hl is changed by catppuccin
    }
  })
  vim.cmd.colorscheme "catppuccin"
end

[alex-courtis]

There's a regression with the sign column and help window placement. Tested clean under 0.8.3

master:

branch:

[alex-courtis]

I'm aware of some breaking changes for floating window backgrounds under nvim 0.9.0.

Parity between branch and master under 0.9.0 is good enough.

[alex-courtis]

Looking good; we need to ensure default behaviour is unchanged.

[jamestansx]

Noted, I have fixed it. You can refer to the following screenshots.

SignColumn:

Help window:

Float Window:

[alex-courtis]

Many thanks for your contribution