[Computercraft] - Console Demo

local sbc = term.setBackgroundColor
local stc = term.setTextColor
local scp = term.setCursorPos
local pa = paintutils
local running = true
local w,h = term.getSize()
local states = {
    inHelp = false,
    inMain = true,
    inMenu = false,
}
function expandBox(fx,fy,tx,ty,col)
    for i =1, tx-fx do
      pa.drawFilledBox(fx,fy,i,ty,col)
      sleep(0.1)
    end
end
function despandBox(fx,fy,tx,ty,col)
    for i =fx-tx, 1 do
      pa.drawFilledBox(fx-i,fy,tx,ty,col)
      sleep(0.1)
    end
end
function cwrite(t,y)
    scp((w/2) - #t/2, y)
    write(t)
end
function drawhelp()
    if(not states.inHelp)then
        despandBox(1,2,12,19,colors.white)
        states.inMain = true
        return
    end
    scp(1,1)
    sbc(colors.gray)
    term.clearLine()
    cwrite("Help Menu",1)
    expandBox(1,2,12,19,colors.gray)
    drawbuttons()
end

function drawmenu()
    if(not states.inMenu)then
        despandBox(1,2,12,19,colors.white)
    else
        expandBox(1,2,12,19,colors.gray)
        drawbuttons()
    end
end

local buttons = {
    {n="Start",x=1,y=1,depends='inMain' or 'inMenu',tc=colors.white,bc=colors.gray,fbc=colors.black,ftc=colors.lightGray,click=function()
         states.inMenu = not states.inMenu
         drawmenu()
    end},
    {n="Help      ",x=2,y=3,depends='inMenu',tc=colors.white,bc=colors.gray,fbc=colors.black,ftc=colors.lightGray,click=function()
        states.inHelp = true
        states.inMain = false
        states.inMenu = false
        drawmenu()
        drawhelp()
    end},
    {n="Reboot    ",x=2,y=4,depends='inMenu',tc=colors.white,bc=colors.gray,fbc=colors.black,ftc=colors.lightBlue,click=function()
        os.reboot()
    end},
    {n="Quit      ",x=2,y=5,depends='inMenu',tc=colors.white,bc=colors.gray,fbc=colors.black,ftc=colors.red,click=function()
    end},
    {n="Topic 1   ",x=2,y=3,depends='inHelp',tc=colors.white,bc=colors.gray,fbc=colors.black,ftc=colors.lightGray,click=function()
    end},
    {n="Topic 2   ",x=2,y=4,depends='inHelp',tc=colors.white,bc=colors.gray,fbc=colors.black,ftc=colors.lightBlue,click=function()
    end},
    {n="Quit      ",x=2,y=5,depends='inHelp',tc=colors.white,bc=colors.gray,fbc=colors.black,ftc=colors.red,click=function()
         states.inHelp = false
         drawhelp()
         redraw()
         drawbuttons()
         states.inMenu = not states.inMenu
         drawmenu()
    end},
}

function drawbuttons()
    -- Draw buttons based on state dependances
    for i = 1, #buttons do
        if(buttons[i].depends == nil or states[buttons[i].depends])then
            -- Draw button
            sbc(buttons[i].bc)
            stc(buttons[i].tc)
            scp(buttons[i].x,buttons[i].y)
            write(buttons[i].n)
        end
    end
end

function flashbutton(n)
    sbc(buttons[n].fbc)
    stc(buttons[n].ftc)
    scp(buttons[n].x,buttons[n].y)
    write(buttons[n].n)
    sleep(0.2)
    sbc(buttons[n].bc)
    stc(buttons[n].tc)
    scp(buttons[n].x,buttons[n].y)
    write(buttons[n].n)
end
function updatebuttons(e)
    if(e[1] == "mouse_click")then
    -- Update buttons based on state dependances
        for i = 1, #buttons do
            if(buttons[i].depends == nil or states[buttons[i].depends])then
                -- Update button
                local x,y = e[3], e[4]
                if(x >= buttons[i].x and x <= buttons[i].x+#buttons[i].n and y == buttons[i].y)then
                     flashbutton(i)
                     buttons[i].click()
                     return
                end
            end
        end
    end
end
function redraw()
    sbc(colors.white)
    term.clear()
    scp(1,1)
    sbc(colors.gray)
    term.clearLine()
    scp(1,1)
    drawbuttons()
end

function loop()
    redraw()
    while running do
        -- Manage screen states (States that change the entire screen layout)
        local e = {os.pullEvent()}
        updatebuttons(e)
    end
end
loop()