neovim/runtime/lua/vim/termcap.lua

102 lines
3.1 KiB
Lua

local M = {}
--- Query the host terminal emulator for terminfo capabilities.
---
--- This function sends the XTGETTCAP DCS sequence to the host terminal emulator asking the terminal
--- to send us its terminal capabilities. These are strings that are normally taken from a terminfo
--- file, however an up to date terminfo database is not always available (particularly on remote
--- machines), and many terminals continue to misidentify themselves or do not provide their own
--- terminfo file, making the terminfo database unreliable.
---
--- Querying the terminal guarantees that we get a truthful answer, but only if the host terminal
--- emulator supports the XTGETTCAP sequence.
---
--- @param caps string|table A terminal capability or list of capabilities to query
--- @param cb function(cap:string, found:bool, seq:string?) Callback function which is called for
--- each capability in {caps}. {found} is set to true if the capability was found or false
--- otherwise. {seq} is the control sequence for the capability if found, or nil for
--- boolean capabilities.
function M.query(caps, cb)
vim.validate({
caps = { caps, { 'string', 'table' } },
cb = { cb, 'f' },
})
if type(caps) ~= 'table' then
caps = { caps }
end
local pending = {} ---@type table<string, boolean>
for _, v in ipairs(caps) do
pending[v] = true
end
local timer = assert(vim.uv.new_timer())
local id = vim.api.nvim_create_autocmd('TermResponse', {
nested = true,
callback = function(args)
local resp = args.data ---@type string
local k, rest = resp:match('^\027P1%+r(%x+)(.*)$')
if k and rest then
local cap = vim.text.hexdecode(k)
if not pending[cap] then
-- Received a response for a capability we didn't request. This can happen if there are
-- multiple concurrent XTGETTCAP requests
return
end
local seq ---@type string?
if rest:match('^=%x+$') then
seq = vim.text
.hexdecode(rest:sub(2))
:gsub('\\E', '\027')
:gsub('%%p%d', '')
:gsub('\\(%d+)', string.char)
end
cb(cap, true, seq)
pending[cap] = nil
if next(pending) == nil then
return true
end
end
end,
})
local encoded = {} ---@type string[]
for i = 1, #caps do
encoded[i] = vim.text.hexencode(caps[i])
end
local query = string.format('\027P+q%s\027\\', table.concat(encoded, ';'))
-- If running in tmux, wrap with the passthrough sequence
if os.getenv('TMUX') then
query = string.format('\027Ptmux;%s\027\\', query:gsub('\027', '\027\027'))
end
io.stdout:write(query)
timer:start(1000, 0, function()
-- Delete the autocommand if no response was received
vim.schedule(function()
-- Suppress error if autocommand has already been deleted
pcall(vim.api.nvim_del_autocmd, id)
-- Call the callback for all capabilities that were not found
for k in pairs(pending) do
cb(k, false, nil)
end
end)
if not timer:is_closing() then
timer:close()
end
end)
end
return M