iOS 5 Core Frameworks: Develop and Design: Working with graphics, location, iCloud, and more

6. Core Graphics

In the coming chapters, I’ll be discussing the Media layer of iOS, one of the four layers of the architecture we introduced in the first chapter. Remember that Core Data, iCloud, and Core Location, Accounts, and Twitter exist primarily in the Core Services layer. The Media layer is an intermediary layer that communicates information from the Core Services and Core OS layers up to the Cocoa Touch layer (which handles user interaction) and back down again. Core Graphics, the first core framework we’ll cover in the Media layer, is responsible for nearly all drawing operations on the iOS screen. When you create any UI element, iOS uses Core Graphics to draw these elements to the window. By implementing and overriding Core Graphics ...