feat(#3213): add view.width.lines_excluded option

doc/nvim-tree-lua.txt

@@ -822,6 +822,15 @@ longest line.
       Type: `string | number | fun(): number|string`
       Default: `-1`
 
+    *nvim-tree.view.width.lines_excluded*
+    Exclude these lines when computing width.
+    Supported values: `"root".
+      Type: `table`
+      Default:
+        `{`
+          `"root"`
+        `}`
+
     *nvim-tree.view.width.padding*
     Extra padding to the right.
       Type: `number | fun(): number|string`
@@ -3323,6 +3332,7 @@ highlight group is not, hard linking as follows: >
 |nvim-tree.view.side|
 |nvim-tree.view.signcolumn|
 |nvim-tree.view.width|
+|nvim-tree.view.width.lines_excluded|
 |nvim-tree.view.width.max|
 |nvim-tree.view.width.min|
 |nvim-tree.view.width.padding|

lua/nvim-tree.lua

@@ -553,6 +553,7 @@ local ACCEPTED_TYPES = {
       "table",
       min = { "string", "function", "number" },
       max = { "string", "function", "number" },
+      lines_excluded = { "table" },
       padding = { "function", "number" },
     },
   },
@@ -612,6 +613,14 @@ local ACCEPTED_STRINGS = {
   },
 }
 
+local ACCEPTED_ENUMS = {
+  view = {
+    width = {
+      lines_excluded = { "root", },
+    },
+  },
+}
+
 ---@param conf table|nil
 local function validate_options(conf)
   local msg
@@ -620,15 +629,19 @@ local function validate_options(conf)
   ---@param def any
   ---@param strs table
   ---@param types table
+  ---@param enums table
   ---@param prefix string
-  local function validate(user, def, strs, types, prefix)
+  local function validate(user, def, strs, types, enums, prefix)
     -- if user's option is not a table there is nothing to do
     if type(user) ~= "table" then
       return
     end
 
-    -- only compare tables with contents that are not integer indexed
-    if type(def) ~= "table" or not next(def) or type(next(def)) == "number" then
+    -- we have hit a leaf enum to validate against - it's an integer indexed table
+    local enum_value = type(enums) == "table" and next(enums) and type(next(enums)) == "number"
+
+    -- only compare tables with contents that are not integer indexed nor enums
+    if not enum_value and (type(def) ~= "table" or not next(def) or type(next(def)) == "number") then
       -- unless the field can be a table (and is not a table in default config)
       if vim.tbl_contains(types, "table") then
         -- use a dummy default to allow all checks
@@ -642,27 +655,33 @@ local function validate_options(conf)
       if not FIELD_SKIP_VALIDATE[k] then
         local invalid
 
-        if def[k] == nil and types[k] == nil then
-          -- option does not exist
-          invalid = string.format("Unknown option: %s%s", prefix, k)
-        elseif type(v) ~= type(def[k]) then
-          local expected
-
-          if types[k] and #types[k] > 0 then
-            if not vim.tbl_contains(types[k], type(v)) then
-              expected = table.concat(types[k], "|")
-            end
-          else
-            expected = type(def[k])
+        if enum_value then
+          if not vim.tbl_contains(enums, v) then
+            invalid = string.format("Invalid value for field %s%s: Expected one of enum '%s', got '%s'", prefix, k, table.concat(enums, "'|'"), tostring(v))
           end
+        else
+          if def[k] == nil and types[k] == nil then
+            -- option does not exist
+            invalid = string.format("Unknown option: %s%s", prefix, k)
+          elseif type(v) ~= type(def[k]) then
+            local expected
+
+            if types[k] and #types[k] > 0 then
+              if not vim.tbl_contains(types[k], type(v)) then
+                expected = table.concat(types[k], "|")
+              end
+            else
+              expected = type(def[k])
+            end
 
-          if expected then
-            -- option is of the wrong type
-            invalid = string.format("Invalid option: %s%s. Expected %s, got %s", prefix, k, expected, type(v))
+            if expected then
+              -- option is of the wrong type
+              invalid = string.format("Invalid option: %s%s. Expected %s, got %s", prefix, k, expected, type(v))
+            end
+          elseif type(v) == "string" and strs[k] and not vim.tbl_contains(strs[k], v) then
+            -- option has type `string` but value is not accepted
+            invalid = string.format("Invalid value for field %s%s: '%s'", prefix, k, v)
           end
-        elseif type(v) == "string" and strs[k] and not vim.tbl_contains(strs[k], v) then
-          -- option has type `string` but value is not accepted
-          invalid = string.format("Invalid value for field %s%s: '%s'", prefix, k, v)
         end
 
         if invalid then
@@ -672,14 +691,14 @@ local function validate_options(conf)
             msg = invalid
           end
           user[k] = nil
-        else
-          validate(v, def[k], strs[k] or {}, types[k] or {}, prefix .. k .. ".")
+        elseif not enum_value then
+          validate(v, def[k], strs[k] or {}, types[k] or {}, enums[k] or {}, prefix .. k .. ".")
         end
       end
     end
   end
 
-  validate(conf, DEFAULT_OPTS, ACCEPTED_STRINGS, ACCEPTED_TYPES, "")
+  validate(conf, DEFAULT_OPTS, ACCEPTED_STRINGS, ACCEPTED_TYPES, ACCEPTED_ENUMS, "")
 
   if msg then
     notify.warn(msg .. "\n\nsee :help nvim-tree-opts for available configuration options")

lua/nvim-tree/view.lua

@@ -12,6 +12,9 @@ local M = {}
 
 local DEFAULT_MIN_WIDTH = 30
 local DEFAULT_MAX_WIDTH = -1
+local DEFAULT_LINES_EXCLUDED = {
+  "root",
+}
 local DEFAULT_PADDING = 1
 
 M.View = {
@@ -303,7 +306,7 @@ function M.open(options)
 end
 
 local function grow()
-  local starts_at = M.is_root_folder_visible(require("nvim-tree.core").get_cwd()) and 1 or 0
+  local starts_at = (M.is_root_folder_visible(require("nvim-tree.core").get_cwd()) and M.View.root_excluded) and 1 or 0
   local lines = vim.api.nvim_buf_get_lines(M.get_bufnr(), starts_at, -1, false)
   -- number of columns of right-padding to indicate end of path
   local padding = get_size(M.View.padding)
@@ -314,31 +317,25 @@ local function grow()
     padding = padding + wininfo[1].textoff
   end
 
-  local resizing_width = M.View.initial_width - padding
-  local max_width
-
-  -- maybe bound max
-  if M.View.max_width == -1 then
-    max_width = -1
-  else
-    max_width = get_width(M.View.max_width) - padding
+  local final_width = M.View.initial_width
+  local max_width = math.huge
+  if M.View.max_width ~= -1 then
+    max_width = get_width(M.View.max_width)
   end
 
   local ns_id = vim.api.nvim_get_namespaces()["NvimTreeExtmarks"]
   for line_nr, l in pairs(lines) do
-    local count = vim.fn.strchars(l)
+    local line_width = vim.fn.strchars(l)
     -- also add space for right-aligned icons
     local extmarks = vim.api.nvim_buf_get_extmarks(M.get_bufnr(), ns_id, { line_nr, 0 }, { line_nr, -1 }, { details = true })
-    count = count + utils.extmarks_length(extmarks)
-    if resizing_width < count then
-      resizing_width = count
-    end
-    if M.View.adaptive_size and max_width >= 0 and resizing_width >= max_width then
-      resizing_width = max_width
+    line_width = line_width + utils.extmarks_length(extmarks) + padding
+    final_width = math.max(final_width, line_width)
+    if final_width >= max_width then
+      final_width = max_width
       break
     end
   end
-  M.resize(resizing_width + padding)
+  M.resize(final_width)
 end
 
 function M.grow_from_content()
@@ -600,6 +597,8 @@ function M.configure_width(width)
     M.View.adaptive_size = true
     M.View.width = width.min or DEFAULT_MIN_WIDTH
     M.View.max_width = width.max or DEFAULT_MAX_WIDTH
+    local lines_excluded = width.lines_excluded or DEFAULT_LINES_EXCLUDED
+    M.View.root_excluded = vim.tbl_contains(lines_excluded, "root")
     M.View.padding = width.padding or DEFAULT_PADDING
   elseif width == nil then
     if M.config.width ~= nil then