A while back I wrote a small swf for the header in my wifes site. I wrote it in flex using an HBox and i set the horizontalScrollPosition of the HBox to slide the images along. I was never very happy with it because despite my best efforts to make it scroll smoothly, I never could, it was always choppy. I ended up experimenting with using just AS3 to do the same thing and the results were great. But I never could figure out what I was doing wrong in flex.
For a client project I came across the need for this scrolling animation again. This time the whole application is in flex so shelling out to just as3 was not an option. I was talking with Ben Stucky ( my go to guru ) and he mentioned that I should not use the horizontalScrollPosition property because he was pretty sure there were at least a couple callLater() method calls in the framework regarding that. Which of course makes perfect sense, because in the as3 version I was only adjusting the x property of the container. A quick modification to my flex code showed better results than using the scroll position of the HBox. But it still wasnt perfect. Another quick search led me back through an old post where I talked about using event.updateAfterEvent() method. After adding this to my function that set the x position the application slides like butter on hot toast.
So my advice in the end of this is if you want smooth moving objects, move them yourself using the x and y coordinates. Avoid properties that are exposed by the framework, and use the updateAfterEvent method to trigger your updates happening right away.
