Autoscrolling script for luakit

autoscroll.lua

----------------------------------------------------------------
-- Simple autoscroll script for luakit (luakit.org)           --
-- Install instructions:                                      --
--  1. Add to rc.lua before window spawning code.             --
--  2. Or: save to $XDG_CONFIG_HOME/luakit/autoscroll.lua and -- 
--     add `require "autoscroll"` to your rc.lua              --
----------------------------------------------------------------

local buf, key = lousy.bind.buf, lousy.bind.key

add_binds("normal", {
    -- Start autoscroll with ,a
    buf("^,a$", function (w) w:set_mode("autoscroll") end),
})

add_binds("autoscroll", {
    -- Increase scrolling speed
    key({}, "+", function (w) 
        w.autoscroll_timer:stop()
        w.autoscroll_timer.interval = math.max(5, w.autoscroll_timer.interval - 5)
        w.autoscroll_timer:start()
    end),

    -- Decrease scrolling speed
    key({}, "-", function (w)
        w.autoscroll_timer:stop()
        w.autoscroll_timer.interval = w.autoscroll_timer.interval + 5
        w.autoscroll_timer:start()
    end),
})

new_mode("autoscroll", {
    -- Start autoscroll timer
    enter = function (w)
        local t = timer{interval=50}
        t:add_signal("timeout", function ()
            w:scroll_vert("+1px")
        end)
        w.autoscroll_timer = t
        t:start()
    end,

    -- Stop autoscroll timer
    leave = function (w) 
        if w.autoscroll_timer then 
            w.autoscroll_timer:stop()
            w.autoscroll_timer = nil
        end
    end,
})

Nice mode!
Just a suggestion, could you set the prompt when the mode starts?
w:set_prompt("-- AUTOSCROLL MODE --") or something like that.

As of luakit 0d5f4ab, this doesn't work.
Apparently scroll_vert is not a valid function.

I've made some changes:

• Replaced scroll_vert for scroll
• Added default scroll keybindings.

Link's here