1. Introduction to Objective-C and Xcode (Part 5) FA 175 Intro to Mobile App Development

2. Agenda Sounds – System Sound Services Images – Image View and the UIImage class

3. Sounds Reference: – http://www.raywenderlich.com/259/audio-101- for-iphone-developers-playing-audio- programmatically http://www.raywenderlich.com/259/audio-101- for-iphone-developers-playing-audio- programmatically Various ways to play sound, depending on format, length, and whether you want sounds played in the background For this class, we will use System Sound Services via the AudioToolbox library

4. Setting up and playing sounds Set up – Define sound id SystemSoundId _soundId; – Specify sound file NSString *file = [[NSBundle mainBundle] pathForResource: @"soundfile" ofType:@"wav"]; NSURL *url =[NSURL fileURLWithPath:file]; – Associate with sound id AudioServicesCreateSystemSoundID((CFURLRef) url, &_soundId); Play – Play by indicating sound id AudioServicesPlaySystemSound(_soundId);

5. Sounds class Create a Sounds class that “houses” sound- related functions Methods: – prepSounds: setup the different sounds to be used by application (executes automatically through load method) – playSoundname: for each of the sound Make sure to – Include AudioToolbox library in frameworks – Include sound files in “Supporting Files” – Make the library and files part of project target

6. Sounds class (version 2) More flexible: allows adding of sound files from outside of the Sounds class – For the first version, you would need to update the Sounds class for every application Methods: – prepSounds: setup the sound ids (array) – setSound: associate file to an idNum (int) – play: plays the sound by indicating the idNum

7. Class methods revisited Take note: the methods of the Sounds class are class methods.h file (interface) contains method declarations with the + prefix When using the class, [Sounds ]; – e.g., [Sounds playWoosh]; // version 1 [Sounds setSound: 3: @"file”: @"wav"]; // ver 2 [Sounds play: 3]; // ver 2

8. Images Image View – Displays an image or animation (described by several images) – Placed within a UI View of a View Controller Associated image can be assigned either – Through the Xcode environment: through attributes inspector – Or programmatically, by setting properties or calling methods on the UIImageView outlet connection

9. UIImage Set image of image view by assigning a UIImage object to the view’s image property self.imageView.image = [UIImage imageNamed:@"x.jpg"]; Make sure all image files needed are included in the “Supporting Files” area (and added to the project’s target

10. Animation Set up an NSArray of images representing the images describing the animation Set two properties of the view – animationImages: the NSArray – animationDuration: number representing the duration (in seconds) for one animation cycle Call startAnimating method on the view

11. Animation Example NSArray *images = [NSArray arrayWithObjects: [UIImage imageNamed:@"x.jpeg"], [UIImage imageNamed:@"y.jpeg"], [UIImage imageNamed:@"z.jpeg"], nil]; self.iv.animationImages = images; self.iv.animationDuration = 0.5; [self.iv startAnimating];

12. Exercise Create a single view project with three buttons and one image view – Set the image of the view to some default image Button 1: changes the image the another image Button 2: plays a sound Button 3: plays a different sound and then runs an animation The project requires 2 sounds and at least 4 images

13. Summary Sounds in an app can be played through Systems Sound Services using the AudioToolbox library – Other frameworks are available – A Sounds class supporting sound support has been created for this course to simplify use Images and animation supported through – UIImageView class – UIImage class