-- right margin of each name in 't', depending on the widths of names in 't.rows'
column_xs = function(rows, init, px)
	local result = {}
	local x = init
	for _,name in ipairs(rows) do
		x = x + App.width(name) + px*2
		table.insert(result, x)
	end
	table.insert(result, x + App.width('Games') + px*2)
	return result
end