Great article. Thanks.

Quick question, I’m using virtual-layout and I’ve a “List” with custom IR with two states: normal, open. How could I avoid recycling the IRs that are in “open” state? So, basically if user open an IR then I don’t wanna recycle that IR when user scrolls down the list.

There are lower level spark components that support virtual layout.

The lowest level is the spark DataGroup (which List uses in its skin). That component doesn’t expose a useVirtualLayout property and in that case you set useVirtualLayout on the layout directly and it is respected.

DataGroup has no concept of chrome (like Group) so it can’t be skinned. If you want to also support spark skinning then look into using the SkinnableDataContainer component (which is what List extends from).

On the mobile front it sounds like you want item snapping and page based scrolling. This is something listed as a B+ feature in the List spec.

I believe implementing this by extending List will be tricky. What I would probably recommend is to use DataGroup and setup your own scrolling logic that then sets the verticalScrollPosition/horizontalScrollPosition directly and animates/snaps appropriately.

This is a great tutorial. Thanks for posting.

Is it necessary to put the SimpleHorizontalLayout inside a List in order to utilize virtual layout? In other words does the outside element have to have the useVirtualLayout property or could we just set it directly on SimpleHorizontalLayout?

I am trying to make a gallery app to flip through a user’s photos, very similar to the iPhone Photos app (but for AIR for Android). I can’t figure out how to overrride the List’s free-form scrolling to change it to image by image. I was going to try extending ListBase as my next effort, but I thought you might have a better suggestion?

Thanks.

Thanks for the tutorial. What if I need to use a tile layout? I am guessing I need to alter some code, but not exactly sure where.

Thanks for the insight.

Thanks for your answer.

I was tried set the x and y of each custom UIComponent datagroup dataprovider, but doesn’t work… Keep positioning in the same way, horizontally.

If you’ve some tip, will welcome.

Tranks!

element.setLayoutBoundsPosition(x, y);

I’ve a question, in this class what we need change to put my elements setting absolute positions (x and y)?