batwidget.lua

-- Battery widget(s) per battery (there might be BAT0 and BAT1).  Interval: 61. {{{
local batwidgets = {}
for _, batnr in ipairs({'0', '1'}) do
  local bat = "BAT" .. batnr
  local batwidget_notification = {}
  local notification_dismissed
  local notification_percent = 20
  local notification_always_percent = 5

  local batwidget = mybasewidget(awful.widget.progressbar())
  batwidgets[#batwidgets+1] = batwidget
  batwidget:set_width(8)
  batwidget:set_vertical(true)

  local f = io.open('/sys/class/power_supply/' .. bat)
  -- TODO: "if not f | return" instead.
  if f then
    f:close()
    my_vicious_register(batwidget, vicious.widgets.bat, function(widget, args)
      local unpack = unpack or table.unpack  -- Lua 5.3: table.unpack
      local state, percent, time, wear = unpack(args)
      if state == "⌁" then  -- "Unknown"
        widget:set_width(0)
      elseif state == "↯" then  -- "Charged"
        -- Hide it only for != BAT0 (usually the only battery then).
        widget:set_width(0)
      else
        widget:set_width(8)
        if bat == "BAT0" and state == "−" and percent <= notification_percent then  -- "Discharging"
          if not notification_dismissed or percent <= notification_always_percent then
            batwidget_notification = naughty.notify({
              preset = naughty.config.presets.critical,
              title = "Battery level is critical!",
              text = "Battery is at "..percent.." percent.",
              run = function(notification)
                notification_dismissed = percent
                notification.die(naughty.notificationClosedReason.dismissedByUser)
              end,
              replaces_id = batwidget_notification.id})
          end
        elseif batwidget_notification.id then
          naughty.destroy(batwidget_notification)
          notification_dismissed = false
        end

        if percent <= 25 then
          widget:set_color(bat == "BAT0" and "#FF5656" or "#AA5656")
        else
          widget:set_color("#AECF96")
        end
      end
      return percent, function()
          return bat .. ": " .. state .. " " .. percent .. "%, time:" .. time .. ", wear: " .. wear
        end
    end, 61, bat)
  end
end