surface_effect/tablet.lua

local S = minetest.get_translator("surface_effect")

local version = "0.0.1"
local width = 15
local height = 10
local winsize = "size["..width..",".. height .."]"
local bgimage = "no_prepend[] bgcolor[#FFFFFF;true] background[0,-1;15,11;surface_effect_tablet_bg.png]"
surface_effect.display = {}

local function get_charge_indicator(power)
    local arm = 65535 / 100
    local percent = (65535 - (power - 65535))/arm

    if percent > 55 then
        return 3
    elseif percent > 15 then
        return 2
    elseif percent < 10 then
        return 1
    end
    return 0
end

function surface_effect.display.main(player, power)
    local pos = player:get_pos()
    local info_biome = minetest.get_biome_data(pos)
    --minetest.log(dump(info_biome))
    local formspec = {
        "formspec_version[4]",
        winsize,
        bgimage,
        "container[0,0]",
        "style_type[label;textcolor=green;bgcolor=red]",
        "label[1.0,0.5;"..S("Software version: @1", minetest.colorize("#FF0000", version)).."]",
        "image[".. width - 2 ..",0.3;1.0,0.5;surface_effect_tablet_charge_level".. get_charge_indicator(power) .. ".png]",
        "container_end[]",
        "image[1.0,1.0;0.7,0.7;surface_effect_thermometer.png]",
        "label[1.5,1.0;"..math.floor(info_biome.heat).."]",
        "button[".. width / 2 .. ",".. height - 1 ..";0.5,0.5;home;|]"
        --"style[weather;textcolor=black;size=2]",
        --"image_button[0.5,0.5;1.5,1.5;surface_effect_weather_btn.png;weather;Weather]"
    }

    return table.concat(formspec, "")
end

minetest.register_tool("surface_effect:tablet", {
    description = S("Tablet"),
    inventory_image = "surface_effect_tablet.png",
    wear_represents = "technic_RE_charge",
    groups = {not_in_creative_inventory = 0},
    on_use = function(stack, player, pointed)
        local name = player:get_player_name()
        local meta = stack:get_meta()
        local charge = meta:get_int("technic:charge")
        if charge == -1 then
            minetest.chat_send_player(name, S("No charge, device needs to be charged"))
        end
        charge = charge - 1

        if charge < 0 then
            technic.set_RE_wear(stack, 0, 65535)
            meta:set_int("technic:charge", -1)
            minetest.chat_send_player(name, S("Not charged, the device needs to be charged"))
        end

        if charge > 0 then
            technic.set_RE_wear(stack, charge, 65535)
            meta:set_int("technic:charge", charge)
            minetest.show_formspec(name, "surface_effect:display_main", surface_effect.display.main(player, charge))
            --stack:set_stack()
        end
        return stack
    end,
})

if minetest.get_modpath("technic") then
    technic.register_power_tool("surface_effect:tablet", 65535)
end