Today I find myself implementing one almost from scratch for my very first ever, all-Flash website! (Oh no, run for it.) And with it, scrollbars.

And with that, I’m discovering that scrollbars are surprisingly complex critters, made even more complex by the fact that Adobe hasn’t given us a decent scrollbar/scrolling class to work with. Which means, in the Flash world, if you want any sort of semi-awesome custom scrollbar, you pretty much have to do it from scratch or work off of other people’s preexisting examples (this is where the “almost” comes in for me).

I continue to find this a little silly because scrollbars are such a common thing and they all have the same basic functionality save for some variables that a user would want to customize. It’s, like, a prime ripe opportunity for class-ifying.

(Actually, turns out, Adobe did make this UI component scrollbar class but it only works with the weird xml layouting scheme for Flex that I know nothing about. Yikes. So what they really need to get a move on is a class that can be instantiated in AS…)

For the seasoned Googler, there are a lot of attempts, sprinkled all over the internets, by various coders of authoring a good scrollbar class. However I still find it a pain that we have to Google for it and spend all this time figuring out if any particular code we’ve found is any good before borrowing it and running with it.

To save some time later, here are a couple that I found that look pretty decent:

• http://as3.kylebrekke.com/2008/advanced-customizable-as3-scrollbar-class-for-adobe-flash-cs3/
• http://www.emstris.com/2009/01/final-scrollbar-class-v-20/
• http://www.kirupa.com/forum/showthread.php?t=245468

The last one is the one I ran with because it was the most abstract one I found. I managed to customize it to dynamically resize to the stage height and width to accomodate liquid layouts. That was the major thing that I needed for this layout that I couldn’t find anywhere else. Also, I made the arrow buttons scroll continuously on press, rather than making the user flick repeatedly.

(That’s another thing I think Adobe seriously shouldn’t have forgotten about… why can’t we just have a continuously firing MouseEvent rather than having to tie an ENTER_FRAME to the MOUSE_DOWN?)

So it seems like there are a lot of existing classes out there, and I’m really just a small fry novice, but I wonder if I should try to find the time to write one of my own. It would be good practice, and other than iffy arithmetic (details, details…), I think I could do it pretty easily using my elementary coding skillz.

Mine at least would have the option of dynamically resizing to stage size, which I think would be really useful for some…

Anyway, back to work.