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Why doesn’t Panel extend LayoutContainer?

As I’m doing some writing for the Flex for Dummies book I was digging into the source code for Panel and the other containers. I was writing about how Panel allows you to set the layout property to either absolute, vertical, or horizontal, just like LayoutContainer (or Application, which extends LayoutContainer). My initial thought was that Panel probably just extends LayoutContainer and that’s where we get the layout property from. But then digging in I saw that both LayoutContainer and Panel independently implement the layout property (in basically a cut and paste exact same way). Unless I’m missing something there’s no reason why Panel shouldn’t just extend LayoutContainer. (BTW, for a recent writeup of the LayoutContainer class see Ben Clinkinbeard’s post here).

If you look at the setter for the layout property it’s almost identical in both Panel and LayoutContainer. And take a look in measure() and updateDisplayList() and you’ll see the same calls to layoutObject.measure() and layoutObject.updateDisplayList().

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