CS 185C/286 - Lecture 12

Cay S. Horstmann

Lecture 12 Quiz 1

How do you make a new array?

1. NSMutableArray *employees = [NSMutableArray array];
2. NSMutableArray *employees = [NSMutableArray alloc];
3. NSMutableArray *employees = new NSMutableArray();
4. Any of the above will construct a new array.

Lecture 12 Quiz 2

What is true about a weak reference?

1. It does not prevent the object to which it points from being garbage collected
2. It is set to nil when the object to which it points is deallocated
3. It does not cause the reference count of the object to which it points to be modified
4. All of the above

Projects

1. Modernize Android client for Android 4, including tablets: Keith, Vakati, Wu. Site
2. Improve device integration with Android and iPhone client: location, phone, schedule, contacts, etc.: Pham, Li X, Li Y. Site
3. HTML5 Cinequest client: Cheung, Nguyen, Yi. Site
4. Hemepath counter app: Dang, Eibagi, Karnes. Site
5. Samsung S-Pen: Sainion, Sivaraman, Tang. Site
6. Port Cinequest app (films only, not schedule) to Windows phone: Anderson, Lehrmann, Yulianto (lead???). Site

Today's Lecture/Lab

• The business of the app store
• What is a monopoly?

App Stores

• Traditionally, independent software vendors (ISVs) produced and distributed software directly to end users
• Disadvantage: installation, update, license enforcement was reinvented by each ISV
• Linux package managers unify installation and update
• Apple introduces app store with iPhone 2
• Apple reviews apps before making them available
• Apple handles billing and takes a percentage of the price
• Android, Blackberry, Windows 8 have their own stores
• Sony, Samsung, Amazon, etc. etc. try the same with limited success

The App Store Business Model

• Developer pays annual fee ($99)
• Apple charges 30% for services (review, hosting, billing)
• Over 800,000 apps available
• In 2011, Apple paid $2B to developers
• Most non-game apps sell for $1, most games for $2
• 12% of apps earn $50K or more, 68% of developers earn < $5K (Source)
• It costs at least $100K to make a competitive iOS app (Source Source, with interesting data)
• In Android, most apps are free and ad-supported
• Get paid roughly $1 per 1,000 ad views
• It works for Apple and Google, so it probably won't change

The Walled Garden

• Traditionally, consumers can install any app on their computer
• Disadvantage: Security, quality risks
• With app store, Apple is sole gatekeeper to iOS apps
• Critera include:
  • No sex, violence, drugs
  • Must feel like an app, not a web page
  • Must not crash
  • No programmability
• Can't run Scratch on an iPad (Source)
• Apple has kept apps off the app store that compete with its business
• Android: Users can choose to install apps from other sources

Is it Your Phone?

• Can Apple legally stop you from putting an app on your phone?
• No absolute right to do with your equipment what you want
• Ex: The DCMA makes it illegal to circumvent copyright restrictions, even if you own the device and media
• Cell phone companies can restrict your ability to unlock a phone, even after the contract is up. (Obama doesn't like it.)
• Game console makers can stop you from running an alternate OS
• Generally, device is considered a part of a “system”
• Not all “systems” claims work. Ex. Lexmark's attempt to use the DCMA to shut out ink refills
• Currently, only legal restriction is antitrust law
• Some efforts to assert against Apple (subscriptions, conversion tools)

What is a Monopoly?

• Monopoly: Sole source of good or service
• Not in itself illegal
• In U.S., illegal to exploit monopoly in one area to gain an unfair advantage in another
• Ex. Microsoft was convicted for using its OS monopoly to unfairly interfere in the market for web browsers (“cutting off Netscape's air supply”)
• Apple has no monopoly on cell phone OS
• Apple was pressured to back off from dictating prices to book and magazine publishers

Reading Before Next Class

• Dr. Pollett recommends the book by Hillegass for learning Objective-C.
• Read chapters 21 - 26
• This won't be on the exam. It's due next Tuesday.

Lab

• Bring your laptop to the lab
• You will work with a buddy
• For this lab, match yourself up with a buddy who has a Mac
• Today, we simply continue following in Dr. Pollett's footsteps. Start here..
• I want you to submit your lab code to git. But don't use the git support in the IDE.
• Instead, tell XCode to put your (unmanaged) project into the workspace/lab11 directory.
• You should be able to finish these activities. If you have extra time, see me to discuss your project progress.