Comments on: Draw Lines with Undo

By: swamy

swamy — Tue, 25 Mar 2008 06:16:48 +0000

404 error please check

By: Mark Wales

Mark Wales — Wed, 30 Nov 2005 19:04:53 +0000

Jesse – you helped me on the Flex mailing list a while back with a question about drawing (I think it is even elsewhere on your blog) but what you have here is exactly the type of thing I was interested in doing but in Flex. In short, I want to drag custom components onto a canvas, draw lines that will connect them and use the dynamic abilities of Flex to allow users to make extremely simple applications. Without resorting to Flash directly, can this be done? (As soon as I get outside Flex explicitly, I feel somewhat lost). Thanks for any advice you might have. -M

By: JesterXL

JesterXL — Tue, 05 Oct 2004 20:45:15 +0000

Paranoia… or no, uh, best practice… yeah yeah, best practice. What would happen if some goob called init twice? For classes, you should allow someone to re-initialize the entire class without having them to have to re-create an instance, via the init function.

I tend to treat simple root level scripts like that too. You can re-init the simple app via calling the init function. Those calls ensure you won’t accidentally have the event handler registered twice. If you didn’t, and you called init twice, then when you clicked undo, it’d undo twice. See what I mean?

By: flashape

flashape — Tue, 05 Oct 2004 07:47:19 +0000

hey, just curious as to why you do this in the code:

Key.removeListener(this);Key.addListener(this);

looks like you do it with all your listener objects.