Now the selection bar "" is rendered only when I define two pointers, such as the first example in your plunker (http://embed.plnkr.co/53AUdB/preview).

It's better if the selection bar appears when I want, also when i use only one pointer..
You could set the selection bar in slider only by configuration or whatever you want.

If you make this issue you make me happy :)

thanks.

PS: I can't send a screenshot of what I am thinking because github have some problem with uploads. I will upload an image as soon as i can.