Lecture 2#- (Intro to Obj-C, Interface Builder and Xcode)

CS193pSpring 2010

Wednesday, March 31, 2010

Enrollment Closed

You should have received an e-mailIt will confirm your grading status (P/NC or not)As usual, we were oversubscribed for grading optionSorry to anyone who didn’t get the option they wantedIf you received e-mail, but are not in Axess, do it!

... and an invitation to iPhone Developer Program

If not, e-mail [email protected].


mailto:[email protected]


Communication

E-mailQuestions are best sent to [email protected] directly to instructor or TA’s risks slow response.

Web SiteVery Important!http://cs193p.stanford.eduAll lectures, assignments, code, etc. will be there.This site will be your best friend when it comes to getting info.




http://cs193p.stanford.edu

http://cs193p.stanford.edu

Office Hours

AndreasMonday 6pm to 8pmThursday 6pm to 8pmGates B26ABring your Stanford ID card for access to the building

SonaliFriday 11am to 1pmThursday 1pm to 3pmGates B26B


Today’s TopicsMVCCalculator

Objective-CDeclaring and implementing objectsSending messages between objects

Interface Builder“Wiring up” objects to send messages to each otherSetting up the properties of objects

XcodeManaging all your codeRunning your application in the simulator


Our Calculator

Model View

Controller

CalculatorViewController

CalculatorBrain

UILabel

UIButton

UIButtonUIButton UIButton

UIButton

UIButton

UIButton


@interface

@end

ModelHeader File (public API)


@interface CalculatorBrain

@end



#import <Foundation/Foundation.h>

@interface CalculatorBrain : NSObject

@end





double operand;{

}

@end





double operand;{

}

- (void)setOperand:(double)anOperand;

- (double)performOperation:(NSString *)operation;

@end



Specifying void as the return type means that this method returns no value.



double operand;{

}



@end





double operand;{

}



@end

The name of this method is “setOperand:”





double operand;{

}



@end

It takes one argument, a double called “anOperand”





double operand;{

}



@end

Don’t forget a semicolon here!





double operand;{

}



@end

This method returns a double.





double operand;{

}



@end

It takes a pointer to an NSString object as its argument.That’s right, we’re passing an object to this method.





double operand;{

}



@end

- (NSArray *)foo:(int)zap bar:(id)pow;





double operand;{

}



@end


This method takes two arguments and is called “foo:bar:”





double operand;{

}



@end


It returns a pointer to an NSArray(a collection class in Foundation).





double operand;{

}



@end


The second argument is of type “id”This means “a pointer to *ANY* kind of object!”





double operand;{

}



@end




#import “CalculatorBrain.h”

@implementation CalculatorBrain

@end

ModelImplementation File (private and public)




@end

- (double)performOperation:(NSString *)operation{ return aDouble;}

- (void)setOperand:(double)anOperand{

}<code goes here>

<code goes here>





@end



}<code goes here>

<code goes here>

No semicolon this time!





@end



}<code goes here>

[operation sendMessage:argument];





@end



}<code goes here>


Square brackets mean “send a message.”





@end



}<code goes here>


This is the object to send the message to(in this case, the NSString called “operation” that was

passed as an argument to performOperation:).





@end



}<code goes here>


This is the message to send.





@end



}<code goes here>


And this is its one (in this case) argument.



Controller

@end

:

#import <UIKit/UIKit.h>

@interface CalculatorViewController UIViewController

IBOutlet UILabel * display;

{

}

- (IBAction)digitPressed:(UIButton *)sender;

CalculatorBrain * brain;

- (IBAction)operationPressed:(UIButton *)sender;


Controller

@end

:




{

}




Our Controller inherits from UIViewController. UIKit supports MVC primarily

through this class.


Controller

@end

:




{

}




This is going to point to our CalculatorBrain Model


Controller

@end

:




{

}




ViewThese hook up to our


Controller

@end

:




{

}




View

Model


CalculatorViewController.xib


“File’s Owner” is ourController

CalculatorViewController.xib


Xcode

A picture (or demo) is worth 1,000 words.


Lecture 2#- (Intro to Obj-C, Interface Builder and Xcode)

Education

Transcript of Lecture 2#- (Intro to Obj-C, Interface Builder and Xcode)