Denver iOS meetup. Murtza Manzur of InMobi spoke at the meetup and talked about apple watch development.

1. Getting Started with Developing for the Apple Watch
Murtza Manzur, Developer Evangelist at InMobi

2. About InMobi
● Largest independent mobile ad network
● 1 billion unique devices
● Products for Publishers: Native Ads, Video Ads
● Products for Advertisers: App-Install Platform

3. MASSIVE REACH ACROSS TOP COMPANIES

4. Agenda
● Apple Watch architecture
● Hello World app for the Apple Watch
● Counter app for the Apple Watch
● Communicating from the Apple Watch to the iOS App

5. Architecture
● Apple Watch app requires an iOS app
● WatchKit apps have two parts
○ A WatchKit extension that runs on iPhone
○ A set of user interface resources that are installed on Apple
Watch.
● Glance
○ Supplemental way for the user to view important
information from your app

6. Architecture
● When Apple Watch app is launched, WatchKit extension on
iPhone runs in the background
○ Updates UI and responds to user interactions
● Watch App
○ Storyboard and resource files
● WatchKit Extension
○ Code associated with the Watch App is executed here

7. Architecture

8. Hello World App for the Apple Watch
● Let’s build a Hello Word app

9. Hello World App - Step 1
Click Create a new Xcode
Project.

10. Hello World App - Step 2
Select Single View
Application, and then click
Next.

11. Hello World App - Step 3
Enter values for
Product Name and
Organization Name.
Select Objective-C as
Language and iPhone
as Devices. Leave Use
Core Data unchecked.

12. Hello World App - Step 4
Select a directory to save the project in, and then click
Create.

13. Hello World App - Step 5
Select File, New, then
click on Target.

14. Hello World App - Step 6
Select Apple Watch in
the left-hand menu.
Then click Next.

15. Hello World App - Step 7
Uncheck Notification
Scene and Glance
Scene. Then click
Finish.

16. Hello World App - Step 8
Click Activate.

17. Hello World App - Step 9
In the left-hand menu,
select the
Interface.storyboard
file from the WatchKit
App folder.

18. Hello World App - Step 10
This is the Interface
Builder for Apple Watch. In
the next step, we will drag
a Label object from the
Object Library to the Apple
Watch interface.

19. Interface Controller
● Like a View Controller in iOS
● Support two navigation styles, which are mutually exclusive
○ Hierarchal
○ Paged based
● Interface navigation through segues or programmatically
○ To implement a modal in your storyboard file, create a modal
segue.
○ To implement a modal programmatically, call the
presentControllerWithName:context: method

20. Interface Controller
● awakeWithContext
○ System calls this method at initialization time to provide the
interface controller with any relevant contextual data from a
previous interface controller
● willActivate
○ System calls this method to notify the interface controller that
its content is about to be displayed onscreen
● didDeactivate
○ System calls this method to notify the interface controller that
it is no longer onscreen

21. Hello World App - Step 10
Search for the Label object in the Object Library (lower
right-hand menu in Xcode). Then drag the Label
Object to the Apple Watch interface.

22. Interface Objects
● Arrange themselves
● Two unique view objects to Watch
App
○ Date
○ Timer
● Can be embedded in vertical or
horizontal groups

23. Hello World App - Step 11
Double click on the Label
object you added to the
Apple Watch interface, and
change the text to Hello
World.

24. Hello World App - Step 11
Click the run icon in Xcode. This will build your app, and
then run it in a simulator.

25. Hello World App - Step 12
To enable the
Apple Watch
simulator, select
Hardware,
External Displays
and then click on
Apple Watch -
42mm.

26. Hello World App - Step 13
Simulator will show
Hello World.

27. Counter App for the Apple Watch
● Let’s build a counter app for the Apple Watch

28. Counter App - Step 1
Navigate back to
Interface.storyboard. Double
click the label text to change
it from Hello World to 0. Add
two Button objects from the
Object Library. Rename the
button text: one for “+”, and
a second for “-”.

29. Counter App - Step 2
Navigate to the InterfaceController.m file in the WatchKit
Extension folder. As shown in the screenshot above, add
two properties between @interface and @end.

30. Counter App - Step 3
In @implementation, add two methods to increment and
decrement the counter property. We will connect these
two methods with the button objects in the Interface
Builder.

31. Counter App - Step 4
In @implementation, add a third method to set the text of
the counter label in the interface to value of the counter
property. We will connect the counter label property to
the counter label object in the interface in a later step.

32. Counter App - Step 5
Connect the
decrementCounter
action to the “-”
button object.
Connect the
incrementCounter
action to the “+”
button object.

33. Counter App - Step 6
Connect the
counterLabel
property from the
Interface Controller
to the counter label
object in the
interface.

34. Counter App - Step 7
Click the run icon in Xcode.

35. Counter App - Step 8
The Watch App will run in
the simulator. If the “+” and
“-” buttons are working
correctly, they will increment
and decrement the counter.

36. Communicating from Watch to iOS App
● Use openParentApplication method to send data from WatchKit
extension to iOS app
■ Passed as a dictionary object
● handleWatchKitExtensionRequest method to receive data on
iOS app
● Reference
○ https://developer.apple.com/library/prerelease/ios/documentati
on/WatchKit/Reference/WKInterfaceController_class/index.ht
ml

37. Resources
● WatchKit Development Tips
○ https://developer.apple.com/watchkit/tips/
● Developing for Apple Watch
○ https://developer.apple.com/library/ios/documentation/General/Con
ceptual/WatchKitProgrammingGuide/index.html

38. Resources
● Tips for Submitting Apple Watch App
○ http://www.fiveminutewatchkit.com/blog/2015/4/2/submitting-your-
watchkit-app
● Bezel, a tool to simulate the look of an Apple Watch

39. Murtza Manzur
Developer Evangelist
murtza.manzur@inmobi.com
Questions?