code-scan starred lsp_signature.nvim

Show function signature when you type

This nvim plugin is made for completion plugins that do not support signature help. Need neovim-0.5+ and enable nvim-lsp.
Part of the code was ported from completion-nvim, which does have lots of cool features.
Fully asynchronous lsp buf request.
Virtual text available

Note: decorator = {"`", "`"} setup is deprecate

Golang with markdown

Highlight with "Search"

signature2.mov

Lua

The plugin also re-write the builtin lsp signature allow the parameter highlight

Using virtual text to show the next parameter

Virtual text only mode

(from @fdioguardi)

Multiple signatures

In case some of the languages allow function overload, the plugin will show all available signatures

Scroll in side signature window

If max_height is set in the config and content exceed max_height, you can scroll up and down in signature window to view the hiding content.

" dein
dein#add('ray-x/lsp_signature.nvim')

" plug
Plug 'ray-x/lsp_signature.nvim'

" Packer
use {
  "ray-x/lsp_signature.nvim",
}

In your init.lua

Call on_attach() when the LSP client attaches to a buffer

e.g. gopls:

local golang_setup = {
  on_attach = function(client, bufnr)
    ...
    require "lsp_signature".on_attach()  -- Note: add in lsp client on-attach
    ...
  end,
  ...
}

require'lspconfig'.gopls.setup(golang_setup)

Alternatively, use setup function

require "lsp_signature".setup()

Configure

Floating window borders

If you have a recent enough build of Neovim, you can configure borders in the signature help floating window(Thanks @Gabriel Sanches for the PR):

local example_setup = {
  on_attach = function(client, bufnr)
    ...
    require "lsp_signature".on_attach({
      bind = true, -- This is mandatory, otherwise border config won't get registered.
      handler_opts = {
        border = "single"
      }
    }, bufnr)
    ...
  end,
  ...
}

Or:

  require'lspconfig'.gopls.setup()
  require "lsp_signature".setup({
    bind = true, -- This is mandatory, otherwise border config won't get registered.
    handler_opts = {
      border = "single"
    }
  })

Full configuration

 cfg = {
  bind = true, -- This is mandatory, otherwise border config won't get registered.
               -- If you want to hook lspsaga or other signature handler, pls set to false
  doc_lines = 2, -- will show two lines of comment/doc(if there are more than two lines in doc, will be truncated);
                 -- set to 0 if you DO NOT want any API comments be shown
                 -- This setting only take effect in insert mode, it does not affect signature help in normal
                 -- mode, 10 by default

  floating_window = true, -- show hint in a floating window, set to false for virtual text only mode
  fix_pos = false,  -- set to true, the floating window will not auto-close until finish all parameters
  hint_enable = true, -- virtual hint enable
  hint_prefix = "🐼 ",  -- Panda for parameter
  hint_scheme = "String",
  use_lspsaga = false,  -- set to true if you want to use lspsaga popup
  hi_parameter = "Search", -- how your parameter will be highlight
  max_height = 12, -- max height of signature floating_window, if content is more than max_height, you can scroll down
                   -- to view the hiding contents
  max_width = 120, -- max_width of signature floating_window, line will be wrapped if exceed max_width
  transpancy = 10, -- set this value if you want the floating windows to be transpant (100 fully transpant), nil to disable(default)
  handler_opts = {
    border = "shadow"   -- double, single, shadow, none
  },

  trigger_on_newline = false, -- set to true if you need multiple line parameter, sometime show signature on new line can be confusing, set it to false for #58
  extra_trigger_chars = {}, -- Array of extra characters that will trigger signature completion, e.g., {"(", ","}
  -- deprecate !!
  -- decorator = {"`", "`"}  -- this is no longer needed as nvim give me a handler and it allow me to highlight active parameter in floating_window
  zindex = 200, -- by default it will be on top of all floating windows, set to 50 send it to bottom
  debug = false, -- set to true to enable debug logging
  log_path = "debug_log_file_path", -- debug log path

  padding = '', -- character to pad on left and right of signature can be ' ', or '|'  etc

  shadow_blend = 36, -- if you using shadow as border use this set the opacity
  shadow_guibg = 'Black', -- if you using shadow as border use this set the color e.g. 'Green' or '#121315'
  toggle_key = nil -- toggle signature on and off in insert mode,  e.g. toggle_key = '<M-x>'
}

require'lsp_signature'.on_attach(cfg, bufnr) -- no need to specify bufnr if you don't use toggle_key

Note: navigator.lua no longer support auto setup for lsp_signature as the setup options is getting more complicated now

Q&A:

Q: What is the default colorscheme in screenshot:

A: aurora

Q: I can not see border after enable border = "single"

A: Try another colorscheme (e.g. colorscheme aurora, or colorscheme luna). If issue persists, please submit an issue

Q: It is not working 😡

A: Here is some trouble shooting: https://github.com/ray-x/lsp_signature.nvim/issues/1

Q:I do not like the pop window background highlight, how to change it?

A: Redefine your NormalFloat and FloatBorder, esp if your colorscheme dose not define it.

Q: How to change parameter highlight

A: By default, the highlight is using "Search" defined in your colorscheme, you can either override "Search" or define, e.g. use IncSearch on_attach({ hi_parameter = "IncSearch"})

Q: I can not see 🐼 in virtual text

A: It is emoji, not nerdfont. Please check how to enable emoji for your terminal.