Marcus and I have started to have NSCoder Nights on Monday’s at Panera Bread on Powers near S. Carefree. We’ve been working to try to learn how to do certain OS X Leopard animation effects using Core Animation. The first challenge we took on was figuring out how to shake a window back and forth to indicate that the user has entered the wrong password in the login window. OS X does this when you try to login and enter your password incorrectly. If you’ve never seen it before, you either don’t have manual login enabled, or you’ve never entered your password incorrectly.
Anyhow, the article is short, but it has an XCode project that you can download and use. Take a look at the post, Core Animation Tutorial: Window Shake Effect and let me know what you think.