rednet.open("down")
local mon = peripheral.wrap( "top" )

os.loadAPI("viewportAPI")
os.loadAPI("buttonAPI")

viewport = viewportAPI.new({term = mon})

button = buttonAPI.new({
	x = 1, y = 1, width = 10, height = 1
})

viewport:addElement(button)
viewport:redraw()

function clickHandler(element, posX, posY)
	element.backgroundColor = element.backgroundColor == colors.white and colors.green or colors.white
	return true
end

button.callback = clickHandler

while true do
	event, side, xPos, yPos = os.pullEvent("mouse_click")
	viewport:handleClick(xPos, yPos)
end