Advanced computer menu, double scroll and graphical addons

local function menu(tOpts,x,y,wd,ht,tInfo,col1,col2)
    term.setCursorBlink(false)
    local selected=1
    local scrolled=0
    local scrolledx=0
    tInfo=tInfo or {}
    local max=0
    for k,v in ipairs(tOpts) do
        tOpts[k]=tostring(v) or ""
        tInfo[k]=tInfo[k] or {}
        max=math.max(max,#v)
    end
    local tColMax={}
    for i=1,#tInfo do
        for k,v in pairs(tInfo[i]) do
            tInfo[i][k]=tostring(v) or ""
            tColMax[k]=math.max(tColMax[k] or 0,#v)
        end
    end
    local totMax=max+2
    for k,v in pairs(tColMax) do
        totMax=totMax+v
    end
    while true do
        term.setTextColor(colors.black)
        for cy=1,ht do
            term.setBackgroundColor(selected-scrolled==cy and (col1 or colors.magenta) or cy==ht and colors.gray or (col2 or colors.purple))
            term.setCursorPos(x,y+cy-1)
            write(string.rep(" ",wd-1))
            term.setBackgroundColor(colors.gray)
            write(" ")
        end
        for k,v in ipairs(tOpts) do
            if k>scrolled and k-scrolled<=ht-2 then
                term.setCursorPos(x,y+k-1-scrolled)
                term.setBackgroundColor(selected==k and (col1 or colors.magenta) or (col2 or colors.purple))
                local line=(k==selected and "[" or " ")..v..(k==selected and "]" or " ")..string.rep(" ",max-#v)
                for col,sInfo in pairs(tInfo[k]) do
                    line=line..sInfo..string.rep(" ",tColMax[col]-#sInfo+1)
                end
                write(string.sub(line,1+scrolledx,wd+scrolledx-2))
            end
        end
        vL=math.ceil(ht*ht/#tOpts)
        hL=math.ceil(wd*wd/totMax)
        term.setBackgroundColor(colors.black)
        term.setCursorPos(math.floor(scrolledx*(totMax-wd)/(totMax-hL)+x),y+ht-1)
        write(string.rep(" ",math.min(hL,wd-math.floor(scrolledx*(totMax-wd)/(totMax-hL)+x)+1)))
        for cy=1,math.min(vL,ht-math.floor(scrolled*(ht-vL-1)/(#tOpts-ht)+y)+1) do
            term.setCursorPos(x+wd-1,math.floor(scrolled*(ht-vL-1)/(#tOpts-ht)+y)+cy-1)
            write(" ")
        end
        term.setCursorPos(x+wd-1,y+ht-1)
        write(" ")

        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.white)
        local evts={os.pullEvent()}
        if ((evts[1]=="mouse_scroll" and evts[2]==-1) or (evts[1]=="key" and evts[2]==200)) and selected>1 then
            selected=selected-1
        elseif ((evts[1]=="mouse_scroll" and evts[2]==1) or (evts[1]=="key" and evts[2]==208)) and selected<#tOpts then
            selected=selected+1
        elseif evts[1]=="key" and evts[2]==203 and scrolledx>0 then
            scrolledx=scrolledx-1
        elseif evts[1]=="key" and evts[2]==205 and scrolledx<totMax-wd+2 then
            scrolledx=scrolledx+1
        elseif evts[1]=="key" and evts[2]==28 then
            return tOpts[selected]
        elseif evts[1]=="mouse_click" and evts[2]==1 and evts[3]>=x and evts[3]<x+wd and tOpts[evts[4]-y+scrolled+1] then
            return tOpts[evts[4]-y+scrolled+1]
        end
        if selected<=scrolled then
            scrolled=selected-1
        elseif selected>scrolled+ht-2 then
            scrolled=selected-ht+2
        end
    end
end


local tOpts,tInfo={},{}
while true do
    local curDir=shell.dir()
    local dirList=fs.list(shell.dir())
    if shell.dir()~="" then table.insert(dirList,1,"..\\") end
    for num,sName in pairs(dirList) do
        table.insert(tOpts,sName)
        table.insert(tInfo,{tostring(fs.isDir(fs.combine(curDir,sName))),tostring(fs.getSize(fs.combine(curDir,sName)))})
    end
    local size={term.getSize()}
    local resp=fs.combine(curDir,menu(tOpts,2,2,size[1]-2,size[2]-2,tInfo))
    if fs.isDir(resp) then
        shell.setDir(resp)
        tOpts={}
    else
        tOpts={}
    end
end