Xcode and Swift CS 4720 Mobile Application Development CS 4720 - - PowerPoint PPT Presentation

CS 4720

Xcode and Swift

CS 4720 – Mobile Application Development

CS 4720

Why Java for Android?

• Let’s first recap: why do you think Android uses

Java?

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Why Java for Android?

• Some good reasons:

– You can’t find a CS major that doesn’t know Java – Java’s relatively easy to pick up – Code runs in a VM, which means you don’t have to recompile for every different phone platform – Tons of tools and support – Java manages pointers and garbage collection automatically, so less likely to get in trouble – Java ME already a thing for mobile

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History of Apple Development

• To appreciate where iOS development came

from, we need to look back at how developing for Apple platforms became what it is

• And that story begins with Smalltalk

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Smalltalk

• Created in the 1970s at Xerox PARC
• Originally built for educational purposes
• Smalltalk is basically THE ancestor for object-
• riented development
• Many of the OO patterns we know (like MVC)

started with Smalltalk

• Major influence in Agile, GUIs, and IDEs

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Smalltalk

• Yes, at the heart of Smalltalk is objects

(everything is an object)

• But the real take away is messaging
• Method calls are effectively messages with

answers

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Smalltalk

42 factorial 2 raisedTo: 4 ‘hello world’ indexOf: $o startingAt: 6 Rectangle width: 100 height: 200 3 + 4 3 > 4

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Objective-C

• In the 1980s, work on Objective-C began at a

telecom company, ITT

• The thought was OO was the future (and

Smalltalk was the blueprint) but backwards compatibility with C legacy systems was important

• The main description of Objective-C was

published in 1986

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Objective-C

• In 1988, NeXT licensed Objective-C and began

work to extend the GCC compiler

• NeXT built foundational tools for building good

user interfaces

• NeXT computers never really took off…
• … but basically everyone thought the toolsets

were really great

• So, NeXT started focusing on software

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NeXTSTEP

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Objective-C

• Oh, by the way…
• NeXT was founded by Steve Jobs after he was

forced out of Apple in the late 1980s…

• NeXT was purchased in full by Apple in 1997
• Jobs took over as CEO of the combined

company at the same time

• Jobs canned several smaller projects (like the

Newton)

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Objective-C

• However, one major project had stalled out
• The creation of the “next generation” Mac OS
• With the purchase of NeXT…
• … and the Unix underpinnings of NeXTSTEP…
• … built using Objective-C…
• Cocoa and OS X were born!

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Cocoa

• Cocoa is the native OO API for OS X
• Built using Objective-C
• Cocoa apps were created using Project Builder

and Interface Builder

– Tools originally created for the NeXTSTEP system

• Cocoa is important in that it “forces”

applications to adhere to Apple UI guidelines

• Project Builder + Interface Builder = Xcode

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Cocoa Touch

• With the creation of iOS, came Cocoa Touch
• Still Objective-C
• Still MVC
• Still Unix-based underneath it all
• So, Objective-C became the default language

for building for iOS

• Until…

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Swift

• Introduced at WWDC 2014 as “Objective-C

without the C”

• Meant to address memory and type safety

issues present in Objective-C

• Switches the message-passing syntax of

Objective-C for the more common dot notation found in Java, etc.

• Builds in many of the old standard Apple data

types (like NSString)

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Swift

• The language itself looks much more “Java-

like” with many keywords carried over

• Semicolons not required though
• In general, shouldn’t take too long for a Java

programmer to pick up

• Uses Objective-C runtime, so it can import any

Objective-C libraries

• Swift 2.0 released September 16, 2015
• Open sourced on December 3, 2015

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Where does this leave us?

• You don’t HAVE to develop iOS apps using

Objective-C or Swift

• However, that is the way to do native

development (yes, you can KINDA do this with some third party tools…)

• As of now, to build iOS apps using Objective-C
• r Swift, you need to use Xcode
• To use Xcode, you need a Mac…

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Developing with Xcode

• If you don’t own a Mac
• Mac Minis in Rice 340
• Unix logins should work
• Check to see if you can swipe in
• Another option is

http://www.macincloud.com/

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Xcode and Swift

• Things to cover:

– Simulators vs. Emulators – How to hook up to Github – Using the Interface Builder to connect code to UI

• bjects

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