neodotfiles/user/.config/awesome/lain/wiki/watch.md

Usage

Read here.

Description

Template for asynchronous watcher widgets.

Executes an input command and makes the user feed a wibox.widget with the output.

local mywatch = lain.widget.watch()

This has been implemented in Awesome 4.0 as awful.widget.watch. But while Awesome watch returns only the widget, Lain one returns a table including its timer and internal update function too.

Input table

Variable	Meaning	Type	Default
widget	Widget to feed	wibox.widget	wibox.widget.textbox
timeout	Refresh timeout seconds	number	5
cmd	The command to execute	string or table	nil
nostart	Widget timer doesn't start immediately	boolean	false
stoppable	Widget timer is stoppable	boolean	false
settings	User settings	function	see Default settings function

If your command needs a shell, you need to set cmd as an array of 3 strings, where the first contains the shell, the second contains -c, and the third contains the actual command. Example:

cmd = { awful.util.shell, "-c", "myactualcommand" }

settings can use the string output, which is the output of cmd.

Default settings function

settings = function() widget:set_text(output) end

Output table

Variable	Meaning	Type
widget	The widget	input widget type or wibox.widget.textbox
update	Update widget	function
timer	The widget timer	gears.timer or nil

The update function can be used to refresh the widget before timeout expires.

If stoppable == true, the widget will have an ad-hoc timer, which you can control though timer variable.

Use case examples

bitcoin

-- Bitcoin to USD current price, using Coinbase V1 API
local bitcoin = lain.widget.watch({
    timeout = 43200, -- half day
    stoppable = true,
    cmd = "curl -m5 -s 'https://coinbase.com/api/v1/prices/buy'",
    settings = function()
        local btc, pos, err = require("lain.util").dkjson.decode(output, 1, nil)
        local btc_price = (not err and btc and btc["subtotal"]["amount"]) or "N/A"

        -- customize here
        widget:set_text(btc_price)
    end
})

btrfs

-- btrfs root df
local myrootfs = lain.widget.watch({
    timeout = 600,
    cmd = "btrfs filesystem df -g /",
    settings  = function()
        local total, used  = string.match(output, "Data.-total=(%d+%.%d+)GiB.-used=(%d+%.%d+)GiB")
        local percent_used = math.ceil((tonumber(used) / tonumber(total)) * 100)

        -- customize here
        widget:set_text(" [/: " .. percent_used .. "%] ")
    end
})

cmus

-- cmus audio player
local cmus = lain.widget.watch({
    timeout = 2,
    stoppable = true,
    cmd = "cmus-remote -Q",
    settings = function()
        local cmus_now = {
            state   = "N/A",
            artist  = "N/A",
            title   = "N/A",
            album   = "N/A"
        }

        for w in string.gmatch(output, "(.-)tag") do
            a, b = w:match("(%w+) (.-)\n")
            cmus_now[a] = b
        end

        -- customize here
        widget:set_text(cmus_now.artist .. " - " .. cmus_now.title)
    end
})

maildir

-- checks whether there are files in the "new" directories of a mail dirtree
local mailpath = "~/Mail"
local mymaildir = lain.widget.watch({
    timeout = 60,
    stoppable = true,
    cmd = { awful.util.shell, "-c", string.format("ls -1dr %s/*/new/*", mailpath) },
    settings = function()
        local inbox_now = { digest = "" }

        for dir in output:gmatch(".-/(%w+)/new") do
            inbox_now[dir] = 1
            for _ in output:gmatch(dir) do
                inbox_now[dir] = inbox_now[dir] + 1
            end
            if #inbox_now.digest > 0 then inbox_now.digest = inbox_now.digest .. ", " end
            inbox_now.digest = inbox_now.digest .. string.format("%s (%d)", dir, inbox_now[dir])
        end

        -- customize here
        widget:set_text("mail: " .. inbox_now.digest)
    end
})

mpris

-- infos from mpris clients such as spotify and VLC
-- based on https://github.com/acrisci/playerctl
local mpris = lain.widget.watch({
    cmd = "playerctl status && playerctl metadata",
    timeout = 2,
    stoppable = true,
    settings = function()
         local escape_f  = require("awful.util").escape
         local mpris_now = {
             state        = "N/A",
             artist       = "N/A",
             title        = "N/A",
             art_url      = "N/A",
             album        = "N/A",
             album_artist = "N/A"
         }

         mpris_now.state = string.match(output, "Playing") or
                           string.match(output, "Paused")  or "N/A"

         for k, v in string.gmatch(output, "'[^:]+:([^']+)':[%s]<%[?'([^']+)'%]?>")
         do
             if     k == "artUrl"      then mpris_now.art_url      = v
             elseif k == "artist"      then mpris_now.artist       = escape_f(v)
             elseif k == "title"       then mpris_now.title        = escape_f(v)
             elseif k == "album"       then mpris_now.album        = escape_f(v)
             elseif k == "albumArtist" then mpris_now.album_artist = escape_f(v)
             end
         end

        -- customize here
        widget:set_text(mpris_now.artist .. " - " .. mpris_now.title)
    end
})

upower

-- battery infos from freedesktop upower
local mybattery = lain.widget.watch({
    timeout = 30,
    cmd = { awful.util.shell, "-c", "upower -i /org/freedesktop/UPower/devices/battery_BAT | sed -n '/present/,/icon-name/p'" },
    settings = function()
        local bat_now = {
            present      = "N/A",
            state        = "N/A",
            warninglevel = "N/A",
            energy       = "N/A",
            energyfull   = "N/A",
            energyrate   = "N/A",
            voltage      = "N/A",
            percentage   = "N/A",
            capacity     = "N/A",
            icon         = "N/A"
        }

        for k, v in string.gmatch(output, '([%a]+[%a|-]+):%s*([%a|%d]+[,|%a|%d]-)') do
            if     k == "present"       then bat_now.present      = v
            elseif k == "state"         then bat_now.state        = v
            elseif k == "warning-level" then bat_now.warninglevel = v
            elseif k == "energy"        then bat_now.energy       = string.gsub(v, ",", ".") -- Wh
            elseif k == "energy-full"   then bat_now.energyfull   = string.gsub(v, ",", ".") -- Wh
            elseif k == "energy-rate"   then bat_now.energyrate   = string.gsub(v, ",", ".") -- W
            elseif k == "voltage"       then bat_now.voltage      = string.gsub(v, ",", ".") -- V
            elseif k == "percentage"    then bat_now.percentage   = tonumber(v)              -- %
            elseif k == "capacity"      then bat_now.capacity     = string.gsub(v, ",", ".") -- %
            elseif k == "icon-name"     then bat_now.icon         = v
            end
        end

        -- customize here
        widget:set_text("Bat: " .. bat_now.percentage .. " " .. bat_now.state)
    end
})