find_overflow_button = function()
	if Overflow_button == nil then return end
	for i,button in ipairs(Global_state.button_handlers) do
		if button == Overflow_button then
			local max_width = 0
			for j=i+1, #Global_state.button_handlers do
				local b = Global_state.button_handlers[j]
				max_width = math.max(max_width, b.w)
			end
			return i, max_width
		end
	end
end