Thinking to the future, what is the behavior of scrollbars on smartphones ?

Still it can be a premature question for my program but it is pure curiosity.
Imagine a typical listbox with its vertical scrollbar.
Ok, how are going to work this listbox in regard with the digital movement on the phone surface ? It is neccesary to implement a new code for mouse ?
Thanks

I don't see any changes "technically", but you can assess it yourself -- turn your resolution down and font size way up and try it...

But a more serious thing is that scrollbars should often be avoided, as they take too much room and a touch screen will provide other possibilities. Instead of scrolling a list by its scrollbars, a user should be able to scroll the list directly by dragging it up & down. This will often mean no page by page browsing of list contents and a real need for minimizing the number of items in the list.

So I have to think that I will need to implement drag, isn't it ?
Thanks