Thanks for the example. Its just what I needed.
Gordon Smith wrote:
>
> I think someone else already explained that you can simply draw into a
> UIComponent rather than into a Sprite or a Shape. All three of these
> have a 'graphics' property which contains a reference to an instance
> of the flash.display.Graphics class, which has methods
> like drawCircle(). But a UIComponent will "just work" with Flex
> containers like VBox while Sprite and Shape require you to do more work.
>
> Here's the Flex Way to create a Ball component (in AS, but you could
> also do it in MXML) that extends UIComponent, and then use it in an
> MXML app:
>
> Ball.as:
> ----------
>
> package
> {
>
> import flash.display.Graphics;
> import mx.core.UIComponent;
>
> public class Ball extends UIComponent
> {
> public function Ball()
> {
> super();
> }
>
> override protected function updateDisplayList(unscaledWidth:Number,
> unscaledHeight:Number):void
> {
> super.updateDisplayList(unscaledWidth, unscaledHeight);
>
> var g:Graphics = graphics;
> g.clear();
> g.beginFill(0x000000);
> g.drawEllipse(0, 0, unscaledWidth, unscaledHeight);
> g.endFill();
> }
> }
>
> }
> BallExample.mxml:
> ---------------------------
>
> <?xml version="1.0" encoding="utf-8"?>
> <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml
> <http://www.adobe.com/2006/mxml>" xmlns:my="*">
> <my:Ball width="100" height="100"/>
> <my:Ball width="200" height="200"/>
> </mx:Application>
>
> You can see that Flex has its own ways of doing certain things that
> you won't find in a book only about ActionScript. For example, you
> should do all of your drawing in an override of the
> updateDisplayList() method, in order to work properly with Flex's
> LayoutManager.
>
> Now you're a Flex component developer! Next you could learn how to
> make the ball have some size even if you don't specify 'width' and
> 'height' in the <mx:Ball> tag. Or add a style to determine the ball's
> color using CSS. Or add an event handler to change the color when the
> user clicks on it. Or let your user create new Ball instances at
> runtime by doing something. Or use effects to move the balls around.
> Or whatever...
>
> As for whether there are examples like this somewhere in our docs... I
> sure hope so! But I can't say for sure as I'm on the development team,
> not the documentation team, and I haven't personally looked through an
> entire documentation set, which is huge.
>
> Gordon Smith
> Adobe Flex SDK Team
>
> ------------------------------------------------------------------------
> *From:* [email protected] [mailto:[EMAIL PROTECTED]
> *On Behalf Of [EMAIL PROTECTED]
> *Sent:* Monday, January 21, 2008 6:03 PM
> *To:* [email protected]
> *Subject:* Re: [flexcoders] Re: addchild
>
>
>
> Gordon Smith wrote:
> >
> > > Why would you think that a book called "actionscript 3 animation"
> > uses only only
> > > flash.* classes throughout and avoids the mx.* classes completely ?
> >
> > It was just a guess, because the title didn't include the word "Flex".
> > Are you saying that this book actually does use mx.* classes?
>
> No it doesn't.You were correct, I just wondered how you would know.
>
> Thanks for the explanations.I still don't understand why there's no
> example of drawing a shape in the flex documentation that doesn't use
> flash.* classes. I understand that the flash.* and sprite based examples
> can be children in a flex application, but you seem to be saying that
> shapes can be created without those classes.
>
> If not, then maybe I misunderstood when you said to start with the flex
> classes. Maybe you were saying, in effect not to start with shapes.
>
> It that correct ?
>
> >
> > > Doesn't Flex use actionscript 3?
> >
> > Yes. As I said, you write AS3 to use both the flash.* classes (which
> > are actually implemented in C++) and the mx.* classes (which are
> > themselves implemented in AS3). And, as I said, the former are
> > low-level classes built into the Player while the latter are
> > high-level classes provided with the Flex framework which get linked
> > into your SWF.
> >
> > > Doesn't it do animation?
> >
> > Yes, it can "do" animation. In fact, Flex's mx.effects.* classes ARE
> > animation classes. But we didn't create Flex to make it easier to make
> > balls move around the stage. The focus of Flex is not Flash-style
> > animations and games, although some developers use it to create just
> > that. Flex is really focused on building Rich Internet Applications,
> > and we provide the most common components that are necessary to do
> > that... things like ComboBox, DataGrid, DateChooser, etc.
> >
> > Gordon Smith
> > Adobe Flex SDK Team
>
>
>
