XCode Animations - Core Graphics:

Ever wanted to be able to use fancy transitions and animations in your Xcode applications? This tutorial provides the method and the means to implement terrific flips and ripples throughout your app, showing window transition effects using both undocumented and documented Objective-C code that can be implemented anywhere quickly and efficiently.

A small, quickly readable eBook that teaches the use of undocumented Core Graphics functionality. This certainly falls in the category of Undocumented Goodness and usage is therefore discouraged. That being said, if you would like to add effects like the ones used in applications like Quicksilver, Virtue Desktops and certain Apple applications I recommend you read this eBook.

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