feat(nvim): add custom tabline plugin

1 files changed, 72 insertions, 0 deletions

diff --git a/plugin/50-tabline.lua b/plugin/50-tabline.lua
new file mode 100644
index 0000000..8628bb2
--- /dev/null
+++ b/plugin/50-tabline.lua
@@ -0,0 +1,72 @@
+-- See `:help stl-%!`
+vim.o.tabline = "%!v:lua.GetTabLine()"
+
+local function set_wincount_hl()
+	-- `link = false` resolves link chains so `.fg`/`.bg` hold actual colors
+	local title = vim.api.nvim_get_hl(0, { name = "Title", link = false })
+	local tabline = vim.api.nvim_get_hl(0, { name = "TabLine", link = false })
+	local tablinesel = vim.api.nvim_get_hl(0, { name = "TabLineSel", link = false })
+	vim.api.nvim_set_hl(0, "dotfiles.TabLineSelIcon", { fg = tabline.fg, bg = tablinesel.bg, bold = true })
+	vim.api.nvim_set_hl(0, "dotfiles.TabLineWinCount", { fg = title.fg, bg = tabline.bg, bold = true, italic = true })
+	vim.api.nvim_set_hl(
+		0,
+		"dotfiles.TabLineSelWinCount",
+		{ fg = title.fg, bg = tablinesel.bg, bold = true, italic = true }
+	)
+end
+set_wincount_hl()
+vim.api.nvim_create_autocmd("ColorScheme", {
+	desc = "Refresh tabline highlights",
+	group = vim.g.dotfiles.augroup,
+	callback = set_wincount_hl,
+})
+
+-- Returns a string compatible with the 'tabline' option, used to set the tabline labels
+-- See `:help 'statusline'`
+function GetTabLine()
+	local s = ""
+	for _, id in pairs(vim.api.nvim_list_tabpages()) do
+		local wins = vim.api.nvim_tabpage_list_wins(id)
+		local is_modified = false
+		for _, win in ipairs(wins) do
+			if vim.bo[vim.api.nvim_win_get_buf(win)].modified then
+				is_modified = true
+				break
+			end
+		end
+		local is_current = id == vim.api.nvim_get_current_tabpage()
+
+		s = s .. "%" .. id .. "T"
+
+		local selected_label, modified_label = "▶ ", "[+] "
+		local win_info = (
+			is_current and "%#dotfiles.TabLineSelIcon# " .. selected_label or "%#dotfiles.TabLineWinCount# "
+		)
+			.. (is_current and "%#dotfiles.TabLineSelWinCount#" or "%#dotfiles.TabLineWinCount#")
+			.. (#wins >= 10 and ">9" or tostring(#wins))
+			.. (is_modified and modified_label or " ")
+		local win_info_display_width = 1 -- leading space
+			+ (is_current and vim.fn.strdisplaywidth(selected_label) or 0)
+			+ (#wins >= 10 and 2 or 1)
+			+ (is_modified and vim.fn.strdisplaywidth(modified_label) or 1)
+		s = s .. win_info
+
+		local total_width = 30
+		local label_width = total_width - win_info_display_width
+		local name = vim.t[vim.api.nvim_tabpage_get_number(id)].tabname
+		name = ((name ~= nil and name ~= "") and name or tostring(id))
+		local display_width = vim.fn.strdisplaywidth(name)
+		if display_width > label_width then
+			name = vim.fn.strcharpart(name, 0, label_width - 1) .. "…"
+		elseif display_width < label_width then
+			name = name .. string.rep(" ", label_width - display_width)
+		end
+		s = s .. (is_current and "%#TabLineSel#" or "%#TabLine#") .. name
+	end
+	return s .. "%#TabLineFill#"
+end
+
+vim.api.nvim_create_user_command("TabRename", function(opts)
+	vim.t.tabname = opts.args
+	vim.cmd.redrawtabline()
+end, { nargs = 1 })