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• SiriKit– Allows the use of voice commands through Siri
• AVKit– Allows playing of audio and video les
• MediaLibrary– Allows access to images, audio, and video stored on
an iOS device
• CallKit– Provides voice calling features
Apple’s frameworks essentially contain code that you can reuse. This makes apps
more reliable and consistent while also saving developers’ time by using proven code
that works correctly. To see a complete list of Apple’s available software frameworks,
visit Apple’s developer documentation site (https://developer.apple.com/
documentation).
Apple’s frameworks can give you a huge head start in creating an iOS app, but you
still need to provide a user interface so users can interact with your app. While you could
create a user interface from scratch, this would also be tedious, time-consuming, and
error-prone. Even worse, if every app developer created a user interface from scratch, no
two iOS apps would look or work exactly the same, confusing users.
That’s why Apple’s Xcode compiler helps you design user interfaces with standard
features used in most apps such as views (windows on the screen), buttons, labels, text
boxes, switches, and sliders. In Xcode, each window of a user interface is called a view.
While simple iOS apps may consist of a single view (think of the Calculator app on an
iPhone), more sophisticated iOS apps consist of multiple views.
To help you create and organize your user interface, Xcode stores an iOS app’s user
interface in a file called a storyboard, which gets its name from the movie industry.
When making films, directors often use storyboards that visually show each scene the
director wants to film. By viewing these storyboard images in a specific sequence, a
director can see how to tell a story before actually filming the scene.
In iOS app development, storyboards contain views and segues. Views appear as
rectangles that represent the screen size of different iOS devices such as an iPhone 8 or
an iPad Pro, while segues appear as arrows that show the order that views appear to the
user as shown in Figure1-2.
Chapter 1 Understanding iOs prOgramming
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