1. A Quick and Dirty Intro to Objective C and iPhone Programming or how I stopped worrying and learned to love Steve Jobs

2. What were going to cover Objective C basics iPhone library basics Writing an app Worshipping Steve Jobs 3. Objective C Another way of doing object oriented C Superset of the C language Uses the Smalltalk idea of message passing rather than method invocation May look familiar to Vision users 4. Objective C Created in the early 80s Adopted by NeXT in 1988 Apple bought NeXT in 1996 and adopted objective C as the language behind Mac OS X 5. HAIL STEVE KING OF NeXT! 6. Message Passing Instead of calling a function we send messages to our object; Foo *myObject; ... [myObject doThingsWithArg:argument]; Object Selector Argument 7. Function Declaration More new syntax: -(void) doThingsWithArg:(int)anArg; Method scope Return Type Selector Argument type Argument name 8. Class Definitions Split into two files .h header .m - implementation 9. Foo.h: @interface Foo : NSObject { int anInt; NSString *aString; } -(void) doThingsWithArg:(int)anArg; @end 10. Foo.m: #import Foo.h @implementation Foo -(void) doThingsWithArg:(int)anArg { } @end 11. Constructors 2 part construction of objects Allocation: Allocation selector is alloc Initialisation: Initialisation selector is custom, but always starts with init by convention. Constructors return id type Standard construction line looks like: [[myObject alloc] init]; 12. Foo.h: @interface Foo : NSObject { int anInt; NSString *aString; } -(id) init; -(id) initWithArg:(int)arg andArg:(NSString*)arg2; -(void) doThingsWithArg:(int)anArg; @end 13. Foo.m: #import Foo.h @implentation Foo -(id) init { return self; } -(id) initWithArg:(int)arg andArg:(NSString*)arg2 { anInt=arg; aString=arg2; return self; } -(void) doThingsWithArg:(int)anArg {} @end 14. Properties New in Objective C 2 Released a couple of years back Automatic construction of accessors Must be declared in header and synthesised in implementation 15. Foo.h: @interface Foo : NSObject { int anInt; NSString *aString; } -(id) init; -(id) initWithArg:(int)arg andArg:(NSString*)arg2; -(void) doThingsWithArg:(int)anArg; @property (readwrite,assign) int anInt; @property (readwrite,copy) NSString *aString; @end 16. Foo.m: #import Foo.h @implentation Foo @synthesize anInt; @synthesize aString; -(id) init { [super init]; return self; } -(id) initWithArg:(int)arg andArg:(NSString*)arg2 { [super init]; myInstanceVar=arg; aString=arg2; return self; } -(void) doThingsWithArg:(int)anArg {} @end 17. Using our new object Foo *myObj1=[[Foo alloc] init]; Foo *myObj2=[[Foo alloc] initWithArg:1 andArg:@Pie]; [myObj1 doStuffWithArg:23]; NSLog(@%d and %@,myObj2.anInt, myObj2.aString); //prints out 1 and Pie NSLog(@%d and %@, [myObj2 getAnInt], [myObj2 getAString]); //also prints out 1 and Pie 18. What was that assign/copy stuff? Objective C has a number of ways of doing memory management Garbage collector New and not used everywhere Allocation pools Baby version of garbage collection Reference counting Used everywhere, including with pools and garbage collection 19. What was that assign/copy stuff? When you get an object its reference count is 1 Use retain to add one to the count Use release to drop one from the count When count hits zero the object is destroyed Destructor method is called dealloc 20. What was that assign/copy stuff? In properties you get to say how you want the reference counts done Assign is a simple assignment, no reference counting Retain returns the pointer to an object and ups the reference count by 1 (for non-objects this just works like assign) Copy returns a copy of the object 21. Reference counting This talk is called quick and dirty because thats all the memory management Im mentioning Im still not sure when to retain things as whether things are copied/retained/etc is generally based on function naming conventions. Lame 22. iPhone The iPhone uses Objective C and a bunch of Apple libraries For many apps you can just bolt together library bits with a little bit of extra logic and data 23. The Steve says LETS MAKE AN APP 24. Going Further THE Cocoa programming book seems to be: Cocoa Programming for Mac OS X by Aaron Hillegass 25. Going Further Series of talks by Evan Doll and Alan Cannistraro up on iTunes U Talks done at Stanford University in Summer 2009 for the 2nd year of their iPhone programming course Missing some iPhone OS 3 features, but very good. 26. Going Further Buy a Mac Make The Steve pleased Wear rollneck sweaters Conform Conform Conform Conform Conform Conform Conform