Javascript: Change scrollable element handle size in scrollbar

Question

Is it possible to programatically access a Div's scrollbar handle and change its size?

--Edit: Is there a mootools plugin for something like this?

I'm trying to implement a lazy pagination mechanism, where a div's content will be updated onscroll, but I'd like the handle on the scrollbar to show the final size. Meaning, if there will be only 10 elements in the div, the handle will be rather large, and if there will be 1000, the handle will be as small as possible, even if the user hasn't loaded all the 1000 elements yet.

I found this site, but I want to avoid using this class.

Thanks!

Answer 1

You would have to use a custom solution for something like this. You won't be able to change the actual native scrollbar height. The plugin you referenced is more along the lines of the route you need to go to acheive the desired results.

Another solution you could implement would be to show the number of results via some other visual method, and not the scrollbar. If you are showing 75 of 100 elements, you could make a fixed div span 75% across the screen.

Answer 2

You could put an empty div inside your scrolled element, and set its height dynamically to something proportional to the actual content size.

Answer 3

You don't get any interface to the scrollbar itself from JavaScript, but it sounds like you can certainly get what you want simply by making the scrolled content as tall as 1000 elements. To reduce the slowness of scripting a thousand items you could replace the above-and-below-the shown-items items with a single top and bottom margin of the same height as that many items, and catch the scroll event to fill in new items to replace them.