CS4720

Xcode andSwift

CS4720– MobileApplicationDevelopment

CS4720

WhyJavaforAndroid?• Let’sfirstrecap:whydoyouthinkAndroidusesJava?

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CS4720

WhyJavaforAndroid?• Somegoodreasons:

– Youcan’tfindaCSmajorthatdoesn’tknowJava– Java’srelativelyeasytopickup– CoderunsinaVM,whichmeansyoudon’thavetorecompileforeverydifferentphoneplatform

– Tonsoftoolsandsupport– Javamanagespointersandgarbagecollectionautomatically,solesslikelytogetintrouble

– JavaMEalreadyathingformobile

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CS4720

HistoryofAppleDevelopment• ToappreciatewhereiOSdevelopmentcamefrom,weneedtolookbackathowdevelopingforAppleplatformsbecamewhatitis

• AndthatstorybeginswithSmalltalk

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CS4720

Smalltalk• Createdinthe1970satXeroxPARC• Originallybuiltforeducationalpurposes• SmalltalkisbasicallyTHEancestorforobject-orienteddevelopment

• ManyoftheOOpatternsweknow(likeMVC)startedwithSmalltalk

• MajorinfluenceinAgile,GUIs,andIDEs

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CS4720

Smalltalk• Yes,attheheartofSmalltalkisobjects(everythingisanobject)

• Buttherealtakeawayismessaging• Methodcallsareeffectivelymessageswithanswers

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CS4720

Smalltalk42 factorial

2 raisedTo: 4

‘hello world’ indexOf: $o startingAt: 6

Rectangle width: 100 height: 200

3 + 4

3 > 4

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CS4720

Objective-C• Inthe1980s,workonObjective-Cbeganatatelecomcompany,ITT

• ThethoughtwasOOwasthefuture(andSmalltalkwastheblueprint)butbackwardscompatibilitywithClegacysystemswasimportant

• ThemaindescriptionofObjective-Cwaspublishedin1986

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CS4720

Objective-C• In1988,NeXTlicensedObjective-CandbeganworktoextendtheGCCcompiler

• NeXTbuiltfoundationaltoolsforbuildinggooduserinterfaces

• NeXTcomputersneverreallytookoff…• …butbasicallyeveryonethoughtthetoolsetswerereallygreat

• So,NeXTstartedfocusingonsoftware

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CS4720

NeXTSTEP

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CS4720

Objective-C• Oh,bytheway…• NeXTwasfoundedbySteveJobsafterhewasforcedoutofAppleinthelate1980s…

• NeXTwaspurchasedinfullbyApplein1997• JobstookoverasCEOofthecombinedcompanyatthesametime

• Jobscannedseveralsmallerprojects(liketheNewton)

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CS4720

Objective-C• However,onemajorprojecthadstalledout• Thecreationofthe“nextgeneration”MacOS• WiththepurchaseofNeXT…• …andtheUnixunderpinningsofNeXTSTEP…• …builtusingObjective-C…• CocoaandOSXwereborn!

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CS4720

Cocoa• CocoaisthenativeOOAPIforOSX• BuiltusingObjective-C• CocoaappswerecreatedusingProjectBuilderandInterfaceBuilder– ToolsoriginallycreatedfortheNeXTSTEP system

• Cocoaisimportantinthatit“forces”applicationstoadheretoAppleUIguidelines

• ProjectBuilder+InterfaceBuilder=Xcode

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CS4720

CocoaTouch• WiththecreationofiOS,cameCocoaTouch• StillObjective-C• StillMVC• StillUnix-basedunderneathitall• So,Objective-CbecamethedefaultlanguageforbuildingforiOS

• Until…

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CS4720

Swift• IntroducedatWWDC2014as“Objective-CwithouttheC”

• MeanttoaddressmemoryandtypesafetyissuespresentinObjective-C

• Switchesthemessage-passingsyntaxofObjective-CforthemorecommondotnotationfoundinJava,etc.

• BuildsinmanyoftheoldstandardAppledatatypes(likeNSString)

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CS4720

Swift• Thelanguageitselflooksmuchmore“Java-like”withmanykeywordscarriedover

• Semicolonsnotrequiredthough• Ingeneral,shouldn’ttaketoolongforaJavaprogrammertopickup

• UsesObjective-Cruntime,soitcanimportanyObjective-Clibraries

• Swift2.0releasedSeptember16,2015• OpensourcedonDecember3,2015

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CS4720

Wheredoesthisleaveus?• Youdon’tHAVEtodevelopiOSappsusingObjective-CorSwift

• However,thatisthewaytodonativedevelopment(yes,youcanKINDAdothiswithsomethirdpartytools…)

• Asofnow,tobuildiOSappsusingObjective-CorSwift,youneedtouseXcode

• TouseXcode,youneedaMac…

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CS4720

DevelopingwithXcode• Ifyoudon’townaMac• MacMinisinRice340• Unixloginsshouldwork• Checktoseeifyoucanswipein• Anotheroptionishttp://www.macincloud.com/

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CS4720

Xcode andSwift• Thingstocover:

– Simulatorsvs.Emulators– HowtohookuptoGithub– UsingtheInterfaceBuildertoconnectcodetoUIobjects

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