This is a full-day tutorial in writing iOS apps in Swift using the Xcode IDE on Macintosh. An iPhone or iPad app is made of intercommunicating objects belonging to Apple’s Cocoa Touch frameworks, and our emphasis will be on these libraries rather than on the Swift language. Learn to create and destroy Cocoa objects, connect them together, and call their methods. Use them to draw text and graphics on the screen, perform simple animations, display controls such as buttons and sliders, respond to a keystroke or other touches, and recognize a gestures such as swipe, tap, and pinch.

We concentrate on three iOS design patterns. A control can call a method of its target object in response to a touch. More generally, an object can call a method of its delegate object in response to a changing situation, e.g., upon reaching the end of an audio file during a playback. A view controller creates the view object underneath it. The view controller and the view can call each other’s methods, and the view controller forms the connection between the view and the rest of the app.