feat: add auto_toggle_bufferline option (#876)

doc/bufferline.txt

@@ -158,6 +158,7 @@ The available configuration are:
             separator_style = "slant" | "slope" | "thick" | "thin" | { 'any', 'any' },
             enforce_regular_tabs = false | true,
             always_show_bufferline = true | false,
+            auto_toggle_bufferline = true | false,
             hover = {
                 enabled = true,
                 delay = 200,

lua/bufferline.lua

@@ -88,6 +88,7 @@ end
 
 --- If the item count has changed and the next tabline status is different then update it
 local function toggle_bufferline()
+  if not config.options.auto_toggle_bufferline then return end
   local item_count = config:is_tabline() and utils.get_tab_count() or utils.get_buf_count()
   local status = (config.options.always_show_bufferline or item_count > 1) and 2 or 0
   if vim.o.showtabline ~= status then vim.o.showtabline = status end

lua/bufferline/config.lua

@@ -649,6 +649,7 @@ local function get_defaults()
     duplicates_across_groups = true,
     enforce_regular_tabs = false,
     always_show_bufferline = true,
+    auto_toggle_bufferline = true,
     persist_buffer_sort = true,
     move_wraps_at_ends = false,
     max_prefix_length = 15,

lua/bufferline/types.lua

@@ -54,6 +54,7 @@
 ---@field public duplicates_across_groups? boolean
 ---@field public enforce_regular_tabs? boolean
 ---@field public always_show_bufferline? boolean
+---@field public auto_toggle_bufferline? boolean
 ---@field public persist_buffer_sort? boolean
 ---@field public move_wraps_at_ends? boolean
 ---@field public max_prefix_length? number