refactor(nvim): split GetTabLine into multiple functions

1 files changed, 35 insertions, 25 deletions

diff --git a/plugin/50-highlight.lua b/plugin/50-highlight.lua
index a0624ba..448eb6e 100644
--- a/plugin/50-highlight.lua
+++ b/plugin/50-highlight.lua
@@ -62,12 +62,41 @@ local function create_tabpage_title_hl()
 	)
 end
 
+-- Builds the window-count segment of a tabpage label, e.g. ` (2)[+] ` (no styling).
+-- `is_modified` appends the `[+]` marker when any window in the tab has pending changes.
+local function make_tab_info_label(win_count, is_modified)
+	local tab_win_count = "(" .. (win_count >= 10 and ">9" or tostring(win_count)) .. ")"
+	local tab_win_count_suffix = is_modified and "[+] " or " "
+	return " " .. tab_win_count .. tab_win_count_suffix
+end
+
+-- Builds the title segment of a tabpage label, padded or truncated to `width` (no styling).
+-- Uses the tab's `tabname` if set, else the active buffer's file name, else `[No Name]`, prefixed
+-- with `*` for the current tab and `-` for the last-accessed tab.
+local function make_tab_label(id, is_current, width)
+	local is_last_accessed = vim.api.nvim_tabpage_get_number(id) == vim.fn.tabpagenr("#")
+	local tab_label_prefix = (is_current and "*" or "") .. (is_last_accessed and "-" or "")
+	local tab_label = vim.t[id].tabname
+	if tab_label == nil or tab_label == "" then
+		local win = vim.api.nvim_tabpage_get_win(id)
+		local bufname = vim.api.nvim_buf_get_name(vim.api.nvim_win_get_buf(win))
+		tab_label = vim.fn.fnamemodify(bufname, ":t:r")
+	end
+	if tab_label == "" then
+		tab_label = "[No Name]"
+	end
+	tab_label = tab_label_prefix .. tab_label
+	local display_width = vim.fn.strdisplaywidth(tab_label)
+	return (display_width > width)
+			and (vim.fn.strcharpart(tab_label, 0, width - 1) .. "…")
+		or (tab_label .. string.rep(" ", width - display_width))
+end
+
 -- Returns a string compatible with the 'tabline' option, used to set the tabline content and style.
 -- Declared as a global function to be available as `v:lua.GetTabLine` in the Vimscript engine for
 -- the 'tabline' option. See `:help 'statusline'`.
--- Each tabpage title is set to show the number of windows, a `[+]` if any of them has pending
--- changes, and the tabpage title (current tabpage is emphasized).
 function GetTabLine()
+	local max_tab_label_width = 30
 	local s = ""
 	for _, id in pairs(vim.api.nvim_list_tabpages()) do
 		local is_current = id == vim.api.nvim_get_current_tabpage()
@@ -83,30 +112,11 @@ function GetTabLine()
 		-- Define start of tabpage label (marks where clickage region begins)
 		s = s .. "%" .. vim.api.nvim_tabpage_get_number(id) .. "T"
 
-		local tab_win_count = "(" .. (#wins >= 10 and ">9" or tostring(#wins)) .. ")"
-		local tab_win_count_suffix = is_modified and "[+] " or " "
-		local tab_info_label = " " .. tab_win_count .. tab_win_count_suffix
-		local tab_info_label_hl = (is_current and "%#TabLineSelWinCount#" or "%#TabLineWinCount#")
-		s = s .. tab_info_label_hl .. tab_info_label
-
-		local max_tab_label_width = 30
+		local tab_info_label = make_tab_info_label(#wins, is_modified)
 		local tab_label_width = max_tab_label_width - vim.fn.strdisplaywidth(tab_info_label)
-		local is_last_accessed = vim.api.nvim_tabpage_get_number(id) == vim.fn.tabpagenr("#")
-		local tab_label_prefix = (is_current and "*" or "") .. (is_last_accessed and "-" or "")
-		local tab_label = vim.t[id].tabname
-		if tab_label == nil or tab_label == "" then
-			local win = vim.api.nvim_tabpage_get_win(id)
-			local bufname = vim.api.nvim_buf_get_name(vim.api.nvim_win_get_buf(win))
-			tab_label = vim.fn.fnamemodify(bufname, ":t:r")
-		end
-		if tab_label == "" then
-			tab_label = "[No Name]"
-		end
-		tab_label = tab_label_prefix .. tab_label
-		local display_width = vim.fn.strdisplaywidth(tab_label)
-		tab_label = (display_width > tab_label_width)
-				and (vim.fn.strcharpart(tab_label, 0, tab_label_width - 1) .. "…")
-			or (tab_label .. string.rep(" ", tab_label_width - display_width))
+		local tab_label = make_tab_label(id, is_current, tab_label_width)
+
+		s = s .. (is_current and "%#TabLineSelWinCount#" or "%#TabLineWinCount#") .. tab_info_label
 		s = s .. (is_current and "%#TabLineSel#" or "%#TabLine#") .. tab_label
 	end
 	return s .. "%#TabLineFill#"