visualshell

--variables
local selected =1
local startposes = {}
local startys = {}
local pcolor = colors.blue
local tcolor = colors.lime
local bgcolor = colors.black



function drawSelections(sel)
    term.setTextColor(tcolor)
    term.setBackgroundColor(bgcolor)
    term.setCursorPos(1,1)
    term.clear()
    local maxL = -1
    for i=1,table.maxn(sel) do
        maxL = math.max(#sel[i],maxL)
    end
    --maxL = maxL/2
    maxL = maxL+1
    --maxL is now the spacing
    local area = 0
    local _,y = term.getSize()
    for i=1,table.maxn(sel) do
        if (i)-(area*y)>y then
            area=area+1
            term.setCursorPos(1,1)
        end
        local _,oy=term.getCursorPos()
        term.setCursorPos(((maxL)/2)+(maxL*area),oy)
        startposes[i] = ((maxL)/2)+(maxL*area)
        startys[i]=oy
        term.write(sel[i])--more effecient than print
        term.setCursorPos(1,oy+1)
    end



end
function drawPointer(sel,start,endc)
    term.setTextColor(pcolor)
    term.setBackgroundColor(bgcolor)
    --draw starter
    term.setCursorPos(startposes[selected]-1,startys[selected])
    term.write(start)
    term.setCursorPos(startposes[selected]+#sel[selected],startys[selected])
    term.write(endc)



end
function movePointer(amm,sel)
    --undo previous pointer\
    if not sel[selected+amm] then
        return false
    end
    drawPointer(sel," "," ")
    --add to pointer
    selected = selected+amm
    drawPointer(sel,"[","]")
end





--test code

local a = shell.programs()--{"Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...","Hi!","bye...",}
table.insert(a,"Return")
drawSelections(a)
movePointer(0,a)
local _,y=term.getSize()
while true do
    local b = {os.pullEvent()}
    if b[1]=="key" then
        if b[2] == 208 then
            movePointer(1,a)
        elseif b[2] ==28 then
            term.clear()
            term.setCursorPos(1,1)
            if selected ==#a then
                error()
            end
            term.write"Args: "
            term.setTextColor(tcolor)
            local args = read()
            shell.run(a[selected].." "..args)
            sleep(1)
            drawSelections(a)
            movePointer(0,a)
        elseif b[2]==200 then
            movePointer(-1,a)
        elseif b[2]==205 then
            movePointer(y,a)
        elseif b[2]==203 then
            movePointer(0-y,a)
        end
    end
end