function fullscreen(c)
    -- Not fullscreen -> fullscreen
    if c.fullscreen then
        awful.util.spawn("polybar-msg cmd hide")

    -- Fullscreen -> not fullscreen
    else
        awful.util.spawn("polybar-msg cmd show")
    end
end

client.connect_signal("property::fullscreen", function(c)
    fullscreen(c)
end)

client.connect_signal("request::activate", function(c)
    fullscreen(c)
end)

screen.connect_signal("tag::history::update", function()
    local screen = awful.screen.focused()
    local tags = screen.selected_tags
    local hide = false

    if tags then
        for _,t in ipairs(tags) do --go through selected tags
            local clients = t:clients()
            if #clients > 0 then for _, client in ipairs(clients) do --ignore case where c is the only present client
                    if client.fullscreen then --if one client is fullscreened the bar needs to be hidden
                        hide = true
                    end
                end
            end
        end
    end
    if hide then
        awful.util.spawn("polybar-msg cmd hide")
    else
        awful.util.spawn("polybar-msg cmd show")
    end
end)