List API

local stx, sty = term.getSize()

function clear()
    term.clear()
    term.setCursorPos(1, 1)
end

function drawlist(title, listr, num)
    clear()
    term.setTextColor(colors.lime)
    local list = {}
    print(title.."\n")
    for i,v in pairs(listr) do
        list[i] = v
    end
    local start = 1
    local last = #list
    if num > sty - 4 then
        start = num - (sty - 4)
    end
    local cnt = 0
    for i = start, #list do
        if cnt > sty - 4 then
            last = last - 1
            cnt = cnt - 1
        end
        cnt = cnt + 1
    end
    for m = start, last do
        local tor = true
        if tor == true then
            if m == num then
                term.setTextColor(colors.white)
                write("[")
                term.setTextColor(colors.lime)
                write("-")
                term.setTextColor(colors.white)
                write("]")
                term.setTextColor(colors.lime)
                print(" "..list[m])
            else
                term.setTextColor(colors.white)
                print("[ ] "..list[m])
            end
        end
    end
end

function getKey()
    local rt = nil
    function lop()
        local e, a1 = os.pullEvent("key")
        if a1 == 200 then
            rt = "up"
        elseif a1 == 208 then
            rt = "down"
        elseif a1 == 28 then
            rt = "enter"
        else
            lop()
        end
    end
    lop()
    repeat sleep(0) until rt ~= nil
    return rt
end

function ch(title, list)
    clear()
    local ind = 1
    local lcopy = list
    drawlist(title, lcopy, ind)
    local rt = nil
    cycle = function()
        local ke = getKey()
        if ke == "up" then
            if ind > 1 then
                ind = ind - 1
            else
                ind = #list
            end
            drawlist(title, lcopy, ind)
            cycle()
        elseif ke == "down" then
            if ind < #list then
                ind = ind + 1
            else
                ind = 1
            end
            drawlist(title, lcopy, ind)
            cycle()
        elseif ke == "enter" then
            rt = ind
        end
    end
    cycle()
    repeat sleep(0) until rt ~= nil
    return ind
end