fix(input): adjust implementation to avoid bugs in prompt buffer (#2)

doc/dressing.txt

@@ -109,5 +109,20 @@ dressing.get_config()                                     *dressing_get_config()
       }
     })
 
+===============================================================================
+                                                                *dressing-prompt*
+Vim has a mechanism that is built for getting input from the user: the
+|prompt-buffer|. This is a specific |buftype| and comes with a lot of special
+handling within vim. Neovim 0.6 and earlier has some bugs with the prompt
+buffer (see https://github.com/stevearc/dressing.nvim/issues/2 and
+https://github.com/neovim/neovim/issues/13715). For this reason, the default
+implementation of |vim.ui.input| does NOT use the prompt buffer, and instead
+mimics its behavior through other means. If you don't mind the bugs, or if
+you're on a version of Neovim after 0.6 (nightly has the fixes now), you can
+pass `prompt_buffer = true` to use that implementation.
+
+There are slight visual differences in where the "prompt" text in placed, but
+otherwise they should be functionally identical.
+
 ===============================================================================
 vim:ft=help:et:ts=2:sw=2:sts=2:norl

doc/tags

@@ -1,6 +1,7 @@
 Dressing	dressing.txt	/*Dressing*
 dressing	dressing.txt	/*dressing*
 dressing-configuration	dressing.txt	/*dressing-configuration*
+dressing-prompt	dressing.txt	/*dressing-prompt*
 dressing.nvim	dressing.txt	/*dressing.nvim*
 dressing.txt	dressing.txt	/*dressing.txt*
 dressing_get_config()	dressing.txt	/*dressing_get_config()*

lua/dressing/config.lua

@@ -18,6 +18,9 @@ local default_config = {
     max_width = nil,
     min_width = 20,
 
+    -- see :help dressing-prompt
+    prompt_buffer = false,
+
     -- see :help dressing_get_config
     get_config = nil,
   },
@@ -60,7 +63,7 @@ local default_config = {
       col = 0,
       border = "rounded",
 
-      -- Window options
+      -- Window transparency (0-100)
       winblend = 10,
 
       -- These can be integers or a float between 0 and 1 (e.g. 0.4 for 40%)

lua/dressing/input.lua

@@ -6,6 +6,7 @@ local context = {
   opts = nil,
   on_confirm = nil,
   winid = nil,
+  title_winid = nil,
 }
 
 local function close_completion_window()
@@ -22,17 +23,40 @@ M.confirm = function(text)
   close_completion_window()
   local ctx = context
   context = {}
-  vim.api.nvim_win_close(ctx.winid, true)
-  vim.cmd("stopinsert")
-  -- stopinsert will move the cursor back 1. We need to move it forward 1 to
-  -- put it in the place you were when you opened the modal.
-  local cursor = vim.api.nvim_win_get_cursor(0)
-  cursor[2] = cursor[2] + 1
-  vim.api.nvim_win_set_cursor(0, cursor)
-  if text == "" then
-    text = nil
-  end
-  vim.schedule_wrap(ctx.on_confirm)(text)
+  -- We have to wait briefly for the popup window to close (if present),
+  -- otherwise vim gets into a very weird and bad state. I was seeing text get
+  -- deleted from the buffer after the input window closes.
+  vim.defer_fn(function()
+    if ctx.title_winid then
+      pcall(vim.api.nvim_win_close, ctx.title_winid, true)
+    end
+    pcall(vim.api.nvim_win_close, ctx.winid, true)
+    vim.cmd("stopinsert")
+    -- stopinsert will move the cursor back 1. We need to move it forward 1 to
+    -- put it in the place you were when you opened the modal.
+    local cursor = vim.api.nvim_win_get_cursor(0)
+    cursor[2] = cursor[2] + 1
+    vim.api.nvim_win_set_cursor(0, cursor)
+    if text == "" then
+      text = nil
+    end
+    -- Defer the callback because we just closed windows and left insert mode.
+    -- In practice from my testing, if the user does something right now (like,
+    -- say, opening another input modal) it could happen improperly. I was
+    -- seeing my successive modals fail to enter insert mode.
+    vim.defer_fn(function()
+      ctx.on_confirm(text)
+    end, 5)
+  end, 5)
+end
+
+M.confirm_non_prompt = function()
+  local text = vim.api.nvim_buf_get_lines(0, 0, 1, true)[1]
+  M.confirm(text)
+end
+
+M.close = function()
+  M.confirm()
 end
 
 M.highlight = function()
@@ -71,7 +95,11 @@ M.completefunc = function(findstart, base)
     return findstart == 1 and 0 or {}
   end
   if findstart == 1 then
-    return vim.api.nvim_strwidth(context.opts.prompt)
+    if global_config.input.prompt_buffer then
+      return vim.api.nvim_strwidth(context.opts.prompt)
+    else
+      return 0
+    end
   else
     local completion = context.opts.completion
     local pieces = split(completion, ",")
@@ -117,9 +145,14 @@ setmetatable(M, {
     end
     local config = global_config.get_mod_config("input", opts)
 
-    local bufnr = vim.api.nvim_create_buf(false, true)
+    -- Create or update the window
     local prompt = opts.prompt or config.default_prompt
-    local width = util.calculate_width(config.prefer_width + vim.api.nvim_strwidth(prompt), config)
+    local width
+    if config.prompt_buffer then
+      width = util.calculate_width(config.prefer_width + vim.api.nvim_strwidth(prompt), config)
+    else
+      width = util.calculate_width(config.prefer_width, config)
+    end
     local winopt = {
       relative = config.relative,
       anchor = config.anchor,
@@ -130,40 +163,96 @@ setmetatable(M, {
       height = 1,
       style = "minimal",
     }
-    local winnr
+    local winid, bufnr, title_winid
+    -- If the input window is already open, hijack it
     if context.winid and vim.api.nvim_win_is_valid(context.winid) then
-      winnr = context.winid
+      winid = context.winid
+      -- Make sure the previous on_confirm callback is called with nil
       vim.schedule(context.on_confirm)
-      vim.api.nvim_win_set_width(winnr, width)
-      bufnr = vim.api.nvim_win_get_buf(winnr)
+      vim.api.nvim_win_set_width(winid, width)
+      bufnr = vim.api.nvim_win_get_buf(winid)
+      title_winid = context.title_winid
     else
-      winnr = vim.api.nvim_open_win(bufnr, true, winopt)
+      bufnr = vim.api.nvim_create_buf(false, true)
+      winid = vim.api.nvim_open_win(bufnr, true, winopt)
     end
     context = {
-      winid = winnr,
+      winid = winid,
+      title_winid = title_winid,
       on_confirm = on_confirm,
       opts = opts,
     }
-    vim.api.nvim_buf_set_option(bufnr, "buftype", "prompt")
+
+    -- Finish setting up the buffer
     vim.api.nvim_buf_set_option(bufnr, "swapfile", false)
     vim.api.nvim_buf_set_option(bufnr, "bufhidden", "wipe")
     vim.api.nvim_buf_set_option(bufnr, "filetype", "DressingInput")
     local keyopts = { silent = true, noremap = true }
-    local close_rhs = "<cmd>lua require('dressing.input').confirm()<CR>"
+    local close_rhs = "<cmd>lua require('dressing.input').close()<CR>"
     vim.api.nvim_buf_set_keymap(bufnr, "n", "<Esc>", close_rhs, keyopts)
     if config.insert_only then
       vim.api.nvim_buf_set_keymap(bufnr, "i", "<Esc>", close_rhs, keyopts)
     end
-    vim.fn.prompt_setprompt(bufnr, prompt)
-    -- Would prefer to use v:lua directly here, but it doesn't work :(
-    vim.fn.prompt_setcallback(bufnr, "dressing#prompt_confirm")
-    vim.fn.prompt_setinterrupt(bufnr, "dressing#prompt_cancel")
+
+    if config.prompt_buffer then
+      vim.api.nvim_buf_set_option(bufnr, "buftype", "prompt")
+      vim.fn.prompt_setprompt(bufnr, prompt)
+      -- Would prefer to use v:lua directly here, but it doesn't work :(
+      vim.fn.prompt_setcallback(bufnr, "dressing#prompt_confirm")
+      vim.fn.prompt_setinterrupt(bufnr, "dressing#prompt_cancel")
+    else
+      local confirm_rhs = "<cmd>lua require('dressing.input').confirm_non_prompt()<CR>"
+      -- If we're not using the prompt buffer, we need to put the prompt into a
+      -- separate title window that will appear in the input window border
+      vim.api.nvim_buf_set_keymap(bufnr, "i", "<C-c>", close_rhs, keyopts)
+      vim.api.nvim_buf_set_keymap(bufnr, "i", "<CR>", confirm_rhs, keyopts)
+      vim.api.nvim_buf_set_keymap(bufnr, "n", "<CR>", confirm_rhs, keyopts)
+      vim.api.nvim_buf_set_lines(bufnr, 0, -1, true, { "" })
+      -- Disable nvim-cmp if installed
+      local ok, cmp = pcall(require, "cmp")
+      if ok then
+        cmp.setup.buffer({ enabled = false })
+      end
+      -- Create the title window once the main window is placed.
+      -- Have to defer here or the title will be in the wrong location
+      vim.defer_fn(function()
+        local titlebuf
+        local trimmed_prompt = string.gsub(prompt, "^%s*(.-)%s*$", "%1")
+        local prompt_width = math.min(width, 2 + vim.api.nvim_strwidth(trimmed_prompt))
+        if context.title_winid and vim.api.nvim_win_is_valid(context.title_winid) then
+          title_winid = context.title_winid
+          titlebuf = vim.api.nvim_win_get_buf(title_winid)
+          vim.api.nvim_win_set_width(title_winid, prompt_width)
+        else
+          titlebuf = vim.api.nvim_create_buf(false, true)
+          title_winid = vim.api.nvim_open_win(titlebuf, false, {
+            relative = "win",
+            win = winid,
+            width = prompt_width,
+            height = 1,
+            row = -1,
+            col = 1,
+            focusable = false,
+            zindex = 151,
+            style = "minimal",
+            noautocmd = true,
+          })
+        end
+        if winid == context.winid then
+          context.title_winid = title_winid
+        end
+        vim.api.nvim_buf_set_lines(titlebuf, 0, -1, true, { " " .. trimmed_prompt })
+        vim.api.nvim_buf_set_option(titlebuf, "bufhidden", "wipe")
+      end, 5)
+    end
+
     if opts.highlight then
       vim.cmd([[
         autocmd TextChanged <buffer> lua require('dressing.input').highlight()
         autocmd TextChangedI <buffer> lua require('dressing.input').highlight()
       ]])
     end
+
     if opts.completion then
       vim.api.nvim_buf_set_option(bufnr, "completefunc", "v:lua.dressing_input_complete")
       vim.api.nvim_buf_set_option(bufnr, "omnifunc", "")
@@ -175,9 +264,11 @@ setmetatable(M, {
         { expr = true }
       )
     end
+
     vim.cmd([[
-        autocmd BufLeave <buffer> ++nested ++once lua require('dressing.input').confirm()
+        autocmd BufLeave <buffer> ++nested ++once lua require('dressing.input').close()
     ]])
+
     vim.cmd("startinsert!")
     if opts.default then
       vim.api.nvim_feedkeys(opts.default, "n", false)

tests/manual/completion.lua

@@ -39,3 +39,13 @@ local function next()
 end
 
 next()
+
+-- Uncomment this to test opening a modal while the previous one is open
+-- vim.ui.input(cases[1], function(text)
+--   print(text)
+-- end)
+-- vim.defer_fn(function()
+--   vim.ui.input(cases[2], function(text)
+--     print(text)
+--   end)
+-- end, 2000)