lsp signature (stealed from nvchad/ui)

lua/configs/lspconfig.lua

@@ -58,3 +58,56 @@ vim.diagnostic.config({
   -- update_in_insert = false,
   -- severity_sort = false,
 })
+
+vim.api.nvim_create_autocmd("LspAttach", {
+  callback = function(args)
+    vim.schedule(function()
+      local client = vim.lsp.get_client_by_id(args.data.client_id)
+
+      if client then
+        local signatureProvider = client.server_capabilities.signatureHelpProvider
+        if signatureProvider and signatureProvider.triggerCharacters then
+          local M = {}
+          local api = vim.api
+
+          vim.lsp.handlers["textDocument/signatureHelp"] = vim.lsp.with(vim.lsp.handlers.signature_help, {
+            focusable = false,
+            silent = true,
+            max_height = 7,
+          })
+
+          local function check_triggeredChars(triggerChars)
+            local cur_line = api.nvim_get_current_line()
+            local pos = api.nvim_win_get_cursor(0)[2]
+            local prev_char = cur_line:sub(pos - 1, pos - 1)
+            local cur_char = cur_line:sub(pos, pos)
+
+            for _, char in ipairs(triggerChars) do
+              if cur_char == char or prev_char == char then
+                return true
+              end
+            end
+          end
+
+          M.setup = function(client, bufnr)
+            local group = api.nvim_create_augroup("LspSignature", { clear = false })
+            api.nvim_clear_autocmds { group = group, buffer = bufnr }
+
+            local triggerChars = client.server_capabilities.signatureHelpProvider.triggerCharacters
+
+            api.nvim_create_autocmd("TextChangedI", {
+              group = group,
+              buffer = bufnr,
+              callback = function()
+                if check_triggeredChars(triggerChars) then
+                  vim.lsp.buf.signature_help()
+                end
+              end,
+            })
+          end
+          M.setup(client, args.buf)
+        end
+      end
+    end)
+  end,
+})