Archive

Archive for June, 2010

Flex 4 List remembering verticalScrollPosition

June 18, 2010 22 comments

A simple requirement, but ~6 hours of frustration.

All I wanted to do was to remember the scroll position that the user was at after an update of the dataprovider items on a list occurred. I had a solution in flex 3 for the (Advanced)DataGrid control that listened for a scroll event and remembered the last known scroll position that would then be set in commit properties after the dataProvider for the grid dispatched a COLLECTION_CHANGE event.

Naturally, I started with that same solution on the Flex 4 list. It was a little trickier, discovering that no event was fired from the list when a scroll event occurred. It turns out that in the skin class, you have to listen to the vertical scroll bar on the scroller object, but this of course is entirely dependent on where your scroller or viewport container that handles scrolling lives, regardless of skinclass.

Read more…