UITableViewCell with 'ball' like calendar App

in the iPhone Calendar app, the view to select th开发者_运维百科e calendar for a particular event has a coloured circle next to the calendar name, drawn with a graduated/3D effect of a ball.

Does anyone have any sample code for how this is drawn - I can draw a solid circle in the UITableViewCell, but I'm not sure how to get the 3D effect.

Thanks.

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You might be able to do this with a CAGradientLayer using a radial gradient, see this answer.

Also, take a look at the documentation on Gradients.

alt text http://developer.apple.com/iphone/library/documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/Art/shaded_sphere.gif