Comments for Bill White's Blog

Comment on Satellite alignment has ‘peaked’ my interest by Irene

Irene — Wed, 11 Aug 2010 19:19:47 +0000

Thanks, Bill. We are in an RV and purchased our DTV HD on the road. We have great HD at home in AZ. Of course, we have not been able to get it working since we got it nearly 3 weeks ago. We called SolidSignal and they said just get the AcuTrac so we’re delighted to see a blurb by someone who’s actually used it. We talked to many techs who said many thngs including it was the wrong dish for our app; and, of course, that it’s too big. Duh! Well, we’re ordering an AcuTrac. But it is huge and we’d prefer a smaller one. But we like the crystal clear sharpness we get on our screen with the HD.
Thanks again for a great post.

Comment on Core Flex 4 – Elements vs Children by Bill

Bill — Fri, 06 Aug 2010 16:09:24 +0000

Thanks Charlie. I agree that they should have included the getElements method and I’m really at a loss to explain why it was left out. At times I’ve wondered why Adobe does things the way they do, but usually I find that I just did not realize their ultimate goal. For example, check out Tink’s comment where he lays out their underlying motive for using Elements. He makes some great points. But I do understand your frustration and I’ve been there myself. :)

Comment on Core Flex 4 – Elements vs Children by charlie crystle

charlie crystle — Thu, 05 Aug 2010 10:09:40 +0000

I would have thought Adobe would be making it easier to develop, and it appears it’s making it harder. Why? Simply documenting and explaining these things would do the job, but Adobe consistently sucks with documentation, samples, and explanations.

The new approach makes a lot of sense–more granular, clearer distinctions. But the absence of getElements and making developers code their own is almost criminal, in that 1) it’s absolutely not obvious and 2) Adobe once again sucks time out of our days where IT SHOULD JUST WORK.

Thanks for the post–if it weren’t for you I’d be stuck again. I’m not as good a coder and the extra insight really helps.

Comment on My own TileUI – Part 1 by Brian

Brian — Mon, 19 Jul 2010 08:53:04 +0000

This is cool. Went to the BumpTop site (http://www.bumptop.com/), but theyve been bought by Google, so no more downloads:( Good for them though

Comment on Core Flex 4 – Elements vs Children by Bill

Bill — Sun, 11 Jul 2010 22:35:25 +0000

Excellent Steven – thanks for pointing that out! :)

Comment on Core Flex 4 – Elements vs Children by Steven Shongrunden

Steven Shongrunden — Sat, 10 Jul 2010 22:51:13 +0000

@Brian Russel Davis – Along with children vs. elements, there is another distinction in spark containers which we think of as elements vs. items. An element is a visual thing like a Rect or a Button, whereas an item is a piece of data that has no visual representation, for example a String or Object. An element can be added to the display using addElement(), but an item can only be added to the display if it is first pushed into an ItemRenderer that is able to turn that data into a visual representation.

In spark, Group/SkinnableContainer are the base containers for dealing with elements and DataGroup/SkinnableDataContainer are the base containers for dealing with items (List extends from SkinnableDataContainer).

These data containers don’t have a concept of elements, but rather have a dataProvider that hold data items that are then turned into visuals using an ItemRenderer. You access the data items of a List/SkinnableDataContainer/DataGroup via the dataProvider property, for example: myList.dataProvider.length.

If you really want access to the item renderer instances that are created by the List you can get at them by using the IVisualElementContainer methods on the List’s dataGroup skin part, for example: myList.dataGroup.numElements.

List has virtual layout on by default so if you have a thousand data items in the List, but only a couple are actually visible at one time then the List will only create renderers for those in view and recycle them when possible. This might be why you are seeing a different number of children than you might expect.

In general you should only access or modify the data items of a List and not access the item renderer instances directly unless you know what you are doing and are aware of the consequences of virtual layout.

Here are some links for more information on DataGroup and virtual layout:

http://opensource.adobe.com/wiki/display/flexsdk/Spark+DataGroup

http://opensource.adobe.com/wiki/display/flexsdk/Spark+Virtualization

http://flexponential.com/2009/07/10/performance-implications-of-the-list-itemrenderer-vs-itemrendererfunction-properties/

Comment on Understanding Custom Flex Component Development by Bill

Bill — Mon, 28 Jun 2010 16:26:00 +0000

Good point. I’ve been hit by that little issue a few times myself! I’ll make a note of it in the article.

Comment on Understanding Custom Flex Component Development by Maulik

Maulik — Mon, 28 Jun 2010 11:56:23 +0000

Great article! Thanks for taking time. However, something many articles forget to mention is that measure() will not be called when width and height are explicitly set. You should consider mentioning it.

Comment on Core Flex 4 – Elements vs Children by Brian Russel Davis

Brian Russel Davis — Wed, 16 Jun 2010 00:07:37 +0000

Hmm .. but this doesn’t seem to work for the List component. There is no numElements and the numChildren seems off. I wrote a simple dataProvider and with 5 elements / attached it / overrode childrenCreated() … 1 child?? doesn’t seem right — I wish the docs / code was more clear here with Adobe — it really makes our job super difficult and time consuming.

Comment on Tile Options Demo using Flex 4 by Bill

Bill — Thu, 10 Jun 2010 18:22:47 +0000

@Rob

I’ll take a look at the filter function. I wrote that logic quite a while ago so and I think I copied it from some Java code I had written so that is probably why I did not take advantage of the filter function. :)

-Bill