How to use the horizontal slider in VRED in my own scripts?

[KristofferHelander]

In VRED there is a horizontal value slider that allows you to slide for infinity. You can see examples of this in the Transform module window for Translate X, Y, Z, see the image below.

There is also a similar slider in the Light Editor for Intensity, but it looks a bit different.

But I can't find something like this in PySide or the VRED API documentation. I've tried the QDial and the QSpinBox but none of them have the same appearence nor quite the same functionallity. QDial only goes one lapse so it is not very intuitive for the user that you can keep sliding. QSpinBox has a min and max value what makes it not an infinite slider, but since I want it to work for position that can be very large values in the scene this could be a problem. Since VRED users are used to this horizontal slider that is also a reason I want to use it, so that it is intuitive for the user to understand how to use the script. 

So how do I create sliders like these in my own script? Can you show me a script example? Thanks!