feat: more style controls in config

lua/input-form/config.lua

@@ -51,6 +51,41 @@ M.defaults = {
   multiline = {
     height = 5,
   },
+  --- Visual styling
+  style = {
+    --- Chevron glyphs shown on the right side of `select` inputs to indicate
+    --- the dropdown state. Override either to taste (e.g. `"v"`/`"^"` for
+    --- ASCII, or extra spacing for wider icons).
+    chevron = {
+      --- Glyph shown when the dropdown is closed.
+      closed = "⌄",
+      --- Glyph shown when the dropdown is open.
+      open = "⌃",
+    },
+    --- Highlight groups applied on every `form:show()`. Each entry is passed
+    --- directly to `vim.api.nvim_set_hl(0, name, spec)`, so any option that
+    --- `nvim_set_hl` accepts (`fg`, `bg`, `link`, `bold`, `italic`,
+    --- `default`, ...) is valid. User overrides fully replace the default
+    --- spec for the matching group (they are NOT deep-merged field by field).
+    highlights = {
+      -- Parent form window
+      InputFormNormal = { link = "NormalFloat", default = true },
+      InputFormBorder = { link = "FloatBorder", default = true },
+      InputFormTitle = { link = "FloatTitle", default = true },
+      InputFormHelp = { fg = "Cyan", default = true },
+      -- Individual input fields
+      InputFormField = { link = "NormalFloat", default = true },
+      InputFormFieldBorder = { link = "FloatBorder", default = true },
+      InputFormFieldTitle = { link = "FloatTitle", default = true },
+      -- Error state for individual input fields
+      InputFormFieldError = { fg = "Red", default = true },
+      InputFormFieldErrorBorder = { fg = "Red", default = true },
+      InputFormFieldErrorTitle = { fg = "Red", default = true },
+      -- Select dropdown list
+      InputFormDropdown = { link = "NormalFloat", default = true },
+      InputFormDropdownActive = { link = "PmenuSel", default = true },
+    },
+  },
 }
 
 M.options = vim.deepcopy(M.defaults)
@@ -60,7 +95,16 @@ M.options = vim.deepcopy(M.defaults)
 ---@param user_opts table|nil
 ---@return table
 function M.setup(user_opts)
-  M.options = utils.merge(vim.deepcopy(M.defaults), user_opts or {})
+  local merged = utils.merge(vim.deepcopy(M.defaults), user_opts or {})
+  -- Highlight specs must be replaced per-group, not deep-merged, so a user
+  -- override like `{ fg = "#ff5555" }` doesn't inherit the default's
+  -- `default = true` flag (which would let a colorscheme clobber it).
+  if user_opts and user_opts.style and user_opts.style.highlights then
+    for name, spec in pairs(user_opts.style.highlights) do
+      merged.style.highlights[name] = spec
+    end
+  end
+  M.options = merged
   return M.options
 end
 

lua/input-form/form.lua

@@ -122,6 +122,10 @@ function M:show()
   -- form buffers. Runs once per nvim session.
   utils.register_ui_exclusions()
 
+  -- Apply configured highlight groups (user-configurable via
+  -- `setup({ style = { highlights = { ... } } })`).
+  self:_apply_highlights()
+
   local layout = self:_compute_layout()
   self._layout = layout
 
@@ -161,9 +165,6 @@ function M:show()
       win_opts.footer_pos = "center"
     end
   end
-  -- Default highlight for the footer (help text): cyan, overridable by the user.
-  pcall(vim.api.nvim_set_hl, 0, "InputFormHelp", { fg = "Cyan", default = true })
-
   self._parent_win = vim.api.nvim_open_win(self._parent_buf, false, win_opts)
   vim.wo[self._parent_win].winblend = config.options.window.winblend
   vim.wo[self._parent_win].winhl = table.concat({
@@ -191,16 +192,21 @@ function M:show()
     self:_install_validation(input)
   end
 
-  -- Default highlight groups for validation error state. `default = true`
-  -- means user overrides take precedence.
-  pcall(vim.api.nvim_set_hl, 0, "InputFormFieldError", { fg = "Red", default = true })
-  pcall(vim.api.nvim_set_hl, 0, "InputFormFieldErrorBorder", { fg = "Red", default = true })
-  pcall(vim.api.nvim_set_hl, 0, "InputFormFieldErrorTitle", { fg = "Red", default = true })
-
   self:_focus(1)
   return self
 end
 
+--- Apply all configured highlight groups. Called from `show()` so live
+--- `setup({ style = { highlights = ... } })` edits take effect on the next
+--- form open.
+function M:_apply_highlights()
+  local style = config.options.style or {}
+  local hls = style.highlights or {}
+  for name, spec in pairs(hls) do
+    pcall(vim.api.nvim_set_hl, 0, name, spec)
+  end
+end
+
 --- Hide the form (close windows) but keep state so `:show()` can reopen it.
 function M:hide()
   if not self._visible then

lua/input-form/inputs/select.lua

@@ -48,12 +48,22 @@ local function label_for(options, id)
   return ""
 end
 
-local CHEVRON_CLOSED = " ▼"
-local CHEVRON_OPEN = " ▲"
+-- Fallbacks in case the config module has been mutated to a malformed state.
+local DEFAULT_CHEVRON_CLOSED = "⌄"
+local DEFAULT_CHEVRON_OPEN = "⌃"
+
+local function chevron_for(open)
+  local style = config.options.style or {}
+  local chev = style.chevron or {}
+  if open then
+    return chev.open or DEFAULT_CHEVRON_OPEN
+  end
+  return chev.closed or DEFAULT_CHEVRON_CLOSED
+end
 
 local function format_display(options, id, width, open)
   local label = label_for(options, id)
-  local chevron = open and CHEVRON_OPEN or CHEVRON_CLOSED
+  local chevron = chevron_for(open)
   if not width or width <= 0 then
     return label .. chevron
   end