feat: add support for column text alignment (#711)

* feat: add support for column text alignment * refactor(util): replace rpad with pad_align * refactor(columns): whitespace handling in parse_col * refactor: small changes * doc: add align option to doc generation * refactor: replace lpad with pad_align --------- Co-authored-by: Steven Arcangeli <stevearc@stevearc.com>
2026-01-14 06:28:16 +01:00 · 2026-01-14 06:28:16 +01:00 · 6b59a6cf62
commit 6b59a6cf62
parent fbbb2a9872
7 changed files with 64 additions and 46 deletions
--- a/doc/oil.txt
+++ b/doc/oil.txt
@ -414,6 +414,7 @@ type                                                                 *column-typ
    Parameters:
      {highlight} `string|fun(value: string): string` Highlight group, or
                  function that returns a highlight group
+      {align}     `"left"|"center"|"right"` Text alignment within the column
      {icons}     `table<string, string>` Mapping of entry type to icon

 icon                                                                 *column-icon*
@ -423,6 +424,7 @@ icon                                                                 *column-ico
    Parameters:
      {highlight}    `string|fun(value: string): string` Highlight group, or
                     function that returns a highlight group
+      {align}        `"left"|"center"|"right"` Text alignment within the column
      {default_file} `string` Fallback icon for files when nvim-web-devicons
                     returns nil
      {directory}    `string` Icon for directories
@ -437,6 +439,7 @@ size                                                                 *column-siz
    Parameters:
      {highlight} `string|fun(value: string): string` Highlight group, or
                  function that returns a highlight group
+      {align}     `"left"|"center"|"right"` Text alignment within the column

 permissions                                                   *column-permissions*
    Adapters: files, ssh
@ -446,6 +449,7 @@ permissions                                                   *column-permission
    Parameters:
      {highlight} `string|fun(value: string): string` Highlight group, or
                  function that returns a highlight group
+      {align}     `"left"|"center"|"right"` Text alignment within the column

 ctime                                                               *column-ctime*
    Adapters: files
@ -455,6 +459,7 @@ ctime                                                               *column-ctim
    Parameters:
      {highlight} `string|fun(value: string): string` Highlight group, or
                  function that returns a highlight group
+      {align}     `"left"|"center"|"right"` Text alignment within the column
      {format}    `string` Format string (see :help strftime)

 mtime                                                               *column-mtime*
@ -465,6 +470,7 @@ mtime                                                               *column-mtim
    Parameters:
      {highlight} `string|fun(value: string): string` Highlight group, or
                  function that returns a highlight group
+      {align}     `"left"|"center"|"right"` Text alignment within the column
      {format}    `string` Format string (see :help strftime)

 atime                                                               *column-atime*
@ -475,6 +481,7 @@ atime                                                               *column-atim
    Parameters:
      {highlight} `string|fun(value: string): string` Highlight group, or
                  function that returns a highlight group
+      {align}     `"left"|"center"|"right"` Text alignment within the column
      {format}    `string` Format string (see :help strftime)

 birthtime                                                       *column-birthtime*
@ -485,6 +492,7 @@ birthtime                                                       *column-birthtim
    Parameters:
      {highlight} `string|fun(value: string): string` Highlight group, or
                  function that returns a highlight group
+      {align}     `"left"|"center"|"right"` Text alignment within the column
      {format}    `string` Format string (see :help strftime)

 --------------------------------------------------------------------------------
--- a/lua/oil/columns.lua
+++ b/lua/oil/columns.lua
@ -98,13 +98,13 @@ end
 M.parse_col = function(adapter, line, col_def)
  local name, conf = util.split_config(col_def)
  -- If rendering failed, there will just be a "-"
-  local empty_col, rem = line:match("^(-%s+)(.*)$")
+  local empty_col, rem = line:match("^%s*(-%s+)(.*)$")
  if empty_col then
    return nil, rem
  end
  local column = M.get_column(adapter, name)
  if column then
-    return column.parse(line, conf)
+    return column.parse(line:gsub("^%s+", ""), conf)
  end
 end

--- a/lua/oil/keymap_util.lua
+++ b/lua/oil/keymap_util.lua
@ -108,7 +108,7 @@ M.show_help = function(keymaps)
  local highlights = {}
  local max_line = 1
  for _, entry in ipairs(keymap_entries) do
-    local line = string.format(" %s   %s", util.rpad(entry.str, max_lhs), entry.desc)
+    local line = string.format(" %s   %s", util.pad_align(entry.str, max_lhs, "left"), entry.desc)
    max_line = math.max(max_line, vim.api.nvim_strwidth(line))
    table.insert(lines, line)
    local start = 1
--- a/lua/oil/loading.lua
+++ b/lua/oil/loading.lua
@ -74,7 +74,8 @@ M.set_loading = function(bufnr, is_loading)
            M.set_loading(bufnr, false)
            return
          end
-          local lines = { util.lpad("Loading", math.floor(width / 2) - 3), bar_iter() }
+          local lines =
+            { util.pad_align("Loading", math.floor(width / 2) - 3, "right"), bar_iter() }
          util.render_text(bufnr, lines)
        end)
      )
--- a/lua/oil/util.lua
+++ b/lua/oil/util.lua
@ -91,34 +91,28 @@ M.get_adapter = function(bufnr, silent)
 end

 ---@param text string
---@param length nil|integer
---@return string
-M.rpad = function(text, length)
-  if not length then
-    return text
+---@param width integer|nil
+---@param align oil.ColumnAlign
+---@return string padded_text
+---@return integer left_padding
+M.pad_align = function(text, width, align)
+  if not width then
+    return text, 0
  end
-  local textlen = vim.api.nvim_strwidth(text)
-  local delta = length - textlen
-  if delta > 0 then
-    return text .. string.rep(" ", delta)
-  else
-    return text
+  local text_width = vim.api.nvim_strwidth(text)
+  local total_pad = width - text_width
+  if total_pad <= 0 then
+    return text, 0
  end
-end

---@param text string
---@param length nil|integer
---@return string
-M.lpad = function(text, length)
-  if not length then
-    return text
-  end
-  local textlen = vim.api.nvim_strwidth(text)
-  local delta = length - textlen
-  if delta > 0 then
-    return string.rep(" ", delta) .. text
+  if align == "right" then
+    return string.rep(" ", total_pad) .. text, total_pad
+  elseif align == "center" then
+    local left_pad = math.floor(total_pad / 2)
+    local right_pad = total_pad - left_pad
+    return string.rep(" ", left_pad) .. text .. string.rep(" ", right_pad), left_pad
  else
-    return text
+    return text .. string.rep(" ", total_pad), 0
  end
 end

@ -314,11 +308,15 @@ M.split_config = function(name_or_config)
  end
 end

+---@alias oil.ColumnAlign "left"|"center"|"right"
+
 ---@param lines oil.TextChunk[][]
 ---@param col_width integer[]
+---@param col_align? oil.ColumnAlign[]
 ---@return string[]
 ---@return any[][] List of highlights {group, lnum, col_start, col_end}
-M.render_table = function(lines, col_width)
+M.render_table = function(lines, col_width, col_align)
+  col_align = col_align or {}
  local str_lines = {}
  local highlights = {}
  for _, cols in ipairs(lines) do
@ -332,9 +330,12 @@ M.render_table = function(lines, col_width)
      else
        text = chunk
      end
-      text = M.rpad(text, col_width[i])
+
+      local unpadded_len = text:len()
+      local padding
+      text, padding = M.pad_align(text, col_width[i], col_align[i] or "left")
+
      table.insert(pieces, text)
-      local col_end = col + text:len() + 1
      if hl then
        if type(hl) == "table" then
          -- hl has the form { [1]: hl_name, [2]: col_start, [3]: col_end }[]
@ -344,15 +345,15 @@ M.render_table = function(lines, col_width)
            table.insert(highlights, {
              sub_hl[1],
              #str_lines,
-              col + sub_hl[2],
-              col + sub_hl[3],
+              col + padding + sub_hl[2],
+              col + padding + sub_hl[3],
            })
          end
        else
-          table.insert(highlights, { hl, #str_lines, col, col_end })
+          table.insert(highlights, { hl, #str_lines, col + padding, col + padding + unpadded_len })
        end
      end
-      col = col_end
+      col = col + text:len() + 1
    end
    table.insert(str_lines, table.concat(pieces, " "))
  end
--- a/lua/oil/view.lua
+++ b/lua/oil/view.lua
@ -668,8 +668,11 @@ local function render_buffer(bufnr, opts)
  local column_defs = columns.get_supported_columns(scheme)
  local line_table = {}
  local col_width = {}
-  for i in ipairs(column_defs) do
+  local col_align = {}
+  for i, col_def in ipairs(column_defs) do
    col_width[i + 1] = 1
+    local _, conf = util.split_config(col_def)
+    col_align[i + 1] = conf and conf.align or "left"
  end

  if M.should_display("..", bufnr) then
@ -692,7 +695,7 @@ local function render_buffer(bufnr, opts)
    end
  end

-  local lines, highlights = util.render_table(line_table, col_width)
+  local lines, highlights = util.render_table(line_table, col_width, col_align)

  vim.bo[bufnr].modifiable = true
  vim.api.nvim_buf_set_lines(bufnr, 0, -1, true, lines)
--- a/scripts/generate.py
+++ b/scripts/generate.py
@ -110,11 +110,16 @@ class ColumnDef:
    params: List["LuaParam"] = field(default_factory=list)


-HL = [
+UNIVERSAL = [
    LuaParam(
        "highlight",
        "string|fun(value: string): string",
        "Highlight group, or function that returns a highlight group",
+    ),
+    LuaParam(
+        "align",
+        '"left"|"center"|"right"',
+        "Text alignment within the column",
    )
 ]
 TIME = [
@ -127,7 +132,7 @@ COL_DEFS = [
        False,
        True,
        "The type of the entry (file, directory, link, etc)",
-        HL
+        UNIVERSAL
        + [LuaParam("icons", "table<string, string>", "Mapping of entry type to icon")],
    ),
    ColumnDef(
@ -136,7 +141,7 @@ COL_DEFS = [
        False,
        False,
        "An icon for the entry's type (requires nvim-web-devicons)",
-        HL
+        UNIVERSAL
        + [
            LuaParam(
                "default_file",
@ -151,23 +156,23 @@ COL_DEFS = [
            ),
        ],
    ),
-    ColumnDef("size", "files, ssh, s3", False, True, "The size of the file", HL + []),
+    ColumnDef("size", "files, ssh, s3", False, True, "The size of the file", UNIVERSAL + []),
    ColumnDef(
        "permissions",
        "files, ssh",
        True,
        False,
        "Access permissions of the file",
-        HL + [],
+        UNIVERSAL + [],
    ),
    ColumnDef(
-        "ctime", "files", False, True, "Change timestamp of the file", HL + TIME + []
+        "ctime", "files", False, True, "Change timestamp of the file", UNIVERSAL + TIME + []
    ),
    ColumnDef(
-        "mtime", "files", False, True, "Last modified time of the file", HL + TIME + []
+        "mtime", "files", False, True, "Last modified time of the file", UNIVERSAL + TIME + []
    ),
    ColumnDef(
-        "atime", "files", False, True, "Last access time of the file", HL + TIME + []
+        "atime", "files", False, True, "Last access time of the file", UNIVERSAL + TIME + []
    ),
    ColumnDef(
        "birthtime",
@ -175,7 +180,7 @@ COL_DEFS = [
        False,
        True,
        "The time the file was created",
-        HL + TIME + [],
+        UNIVERSAL + TIME + [],
    ),
 ]