Button API

    local mon
    local button = {}

    function clear()
       button = {}
    end

    function startup(monDirection)
            mon = peripheral.wrap(monDirection)
            mon.setTextScale(1)
            mon.setTextColor(colors.white)
            mon.setBackgroundColor(colors.black)
    end

    function addButton(name, func, param, x, y, width, height, backColorInactive, backColorActive, textColorInactive, textColorActive)
            if (backColorInactive == nil or backColorInactive == "") then
                    backColorInactive = colors.red
            end
            if (backColorActive == nil or backColorActive == "") then
                    backColorActive = colors.lime
            end
            if (textColorInactive == nil or textColorInactive == "") then
                    textColorInactive = colors.white
            end
            if (textColorActive == nil or textColorInactive == "") then
                    textColorActive = colors.white
            end

            button[name] = {}
            button[name]["func"] = func
            button[name]["active"] = false
            button[name]["enabled"] = true
            button[name]["param"] = param
            button[name]["xmin"] = x
            button[name]["ymin"] = y
            button[name]["xmax"] = x + width
            button[name]["ymax"] = y + height
            button[name]["bcolin"] = backColorInactive
            button[name]["bcolac"] = backColorActive
            button[name]["tcolin"] = textColorInactive
            button[name]["tcolac"] = textColorActive
    end

    -- This doesn't remove the button from any screen it's drawn on, it simply removes all functionality of the button and prevents it from being re-drawn.
    function removeButton(name)
            if (button[name] ~= nil) then
                    button[name] = nil
            end
    end

    function renameButton(oldName, newName, reDraw)
            local k,v

            button[newName] = {}

            for k,v in pairs(button[oldName]) do
                    button[newName][k] = v
            end

            button[oldName] = nil

            if (reDraw == true) then
                    drawButton(newName)
            end
    end

    function disableButton(name)
            if (button[name] ~= nil) then
                    button[name]["enabled"] = false
            end
    end

    function enableButton(name)
            if (button[name] ~= nil) then
                    button[name]["enabled"] = true
            end
    end

    function drawButton(name)
            local backColor
            local textColor
            local y
            local padding = "                                                                                                    "

            if (button[name]["active"] == true) then
                    backColor = button[name]["bcolac"]
                    textColor = button[name]["tcolac"]
            else
                    backColor = button[name]["bcolin"]
                    textColor = button[name]["tcolin"]
            end

            mon.setBackgroundColor(backColor)
            mon.setTextColor(textColor)

            -- Writes the button active/inactive color
            for y = button[name]["ymin"], button[name]["ymax"] do
                    mon.setCursorPos(button[name]["xmin"], y)
                    mon.write(string.sub(padding, 1, button[name]["xmax"] - button[name]["xmin"]))
            end

            -- Write the button text centered in the button
            mon.setCursorPos(button[name]["xmin"] + math.floor((button[name]["xmax"] - button[name]["xmin"] - string.len(name)) / 2), button[name]["ymin"] + math.floor((button[name]["ymax"] - button[name]["ymin"]) / 2))
            mon.write(string.upper(string.sub(name, 1, 1)) .. string.sub(name, 2))
    end

    function drawButtons()
            local name

            for name in pairs(button) do
                    drawButton(name)
            end
    end

    function toggleButton(name, reDraw)
            if (button[name] ~= nil) then
                    button[name]["active"] = not button[name]["active"]

                    if (reDraw == true) then
                            drawButton(name)
                    end
            end
    end

    function flash(name, duration)
            if (duration == nil or duration == "") then
                    duration = 0.15
            end

            toggleButton(name, true)
            sleep(duration)
            toggleButton(name, true)
    end

    function activate(name)
            if (button[name] ~= nil) then
                    button[name]["active"] = true
                    drawButton(name)
            end
    end

    function deActivate(name)
            if (button[name] ~= nil) then
                    button[name]["active"] = false
                    drawButton(name)
            end
    end

    function checkxy(x, y)
            local name

            if (button ~= nill) then
                    for name in pairs(button) do
                            if (y >= button[name]["ymin"] and  y <= button[name]["ymax"]) then
                                    if (x >= button[name]["xmin"] and x <= button[name]["xmax"]) then
                                            if (button[name]["enabled"] == true) then
                                                    if (button[name]["param"] == "") then
                                                            button[name]["func"]()
                                                    else
                                                            button[name]["func"](button[name]["param"])
                                                    end

                                                    return true
                                            end
                                    end
                            end
                    end
            end

            return false
    end