CS 696 Mobile Application Development Fall Semester, 2011 ...First Example 3 Counter + increases count - decrease count Thursday, September 15, 2011

CS 696 Mobile Application DevelopmentFall Semester, 2011

Doc 7 iPhone App IntroSep 15, 2011

Copyright ©, All rights reserved. 2011 SDSU & Roger Whitney, 5500 Campanile Drive, San Diego, CA 92182-7700 USA. OpenContent (http://www.opencontent.org/openpub/) license defines the copyright on this document.

Thursday, September 15, 2011

References

2

View Controller Programming Guide for iOS

iPhone Application Programming Guide

Various UIKit class's documentation

CS 193P Standford iPhone Application Development, Lecture 4, http://itunes.apple.com/us/podcast/lecture-4-slides-january-14/id384233225?i=85092607


First Example

3

Counter+ increases count- decrease count


Things to Master

4

Concepts Frameworks

Application & Delegation

Model View Contoller

Events

UIKitClasses, methodsHow it works

Tools

XcodeInterface builderxib filesresources etc


MVC - Model View Controller

5

ModelApp data & functionality

ViewThe user interface

ControllerIntermediary between Model & ViewWhen model changes updates viewWhen user interacts with view updates modelApp logic lives here (sigh)


App Code

6

View

Controller

Model


UIApplication

7

All iOS apps are instances of UIApplication class

Handles lifecycle of the application

Handles events from OS

Manages status bar

Contains all applicaition windows


OS Events & Your App

8

Some OS events have to be handled by your code

App startedApp moving to backgroundApp terminatingApp received memory warningApp received notification


How does your code get the events?

9

UIApplication

AppSubclassA AppSubclassB

Common Java pattern - create subclass

But iOS does not use this pattern


Delegate

10

entrust (a task or responsibility) to another person

UIApplicationDelegate

View

Controller

Model

OS

Your Code


Delegate Pattern

11

Common pattern in iOS framework

Framework class in charge of some task

Parts of task must be done by your code

Rather than subclass framework class

Framework class uses a delegate class

Uses delegate to perform some of its tasks

We implement a delegate class


Counter Project

12

Click on + Calls increasePressed method on controllerController has view update value

Click on -Calls increasePressed method on controllerController has view update value

+ & - button

2label that changes with count


Starting new Project - Xcode 4

13


Starting new Project - Xcode 4

14


Files Created For Counter Project

15

ClassesCounterAppDelegate.hCounterAppDelegate.mCounterViewController.hCounterViewController.m

Other SourcesCounter_Prefix.pchmain.mCounterViewController.xibMainWindow.xibCounter-Info.plist

(Where is the model?)


main.m

16

#import

int main(int argc, char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; int retVal = UIApplicationMain(argc, argv, nil, nil); [pool release]; return retVal;}


Counter_Prefix.pch

17

#ifdef __OBJC__ #import #import #endif


Counter-Info.plist

18

plist - property list


CounterViewController.h

19

#import

@interface CounterViewController : UIViewController {

}

@end


We will add to this class

CounterAppDelegate

20

#import

@class CounterViewController;

@interface CounterAppDelegate : NSObject { UIWindow *window; CoutnerViewController *viewController;}

@property (nonatomic, retain) IBOutlet UIWindow *window;@property (nonatomic, retain) IBOutlet CounterViewController *viewController;

@end


We will deal this class for a while

Creating the view

21

Use Interface Builder to draw view

or

Create view in code


Views with Interface Builder

22

Draw the view in Interface Builder

Save the view (xib file)

Declare connections in code

Make connection in Interface Builder


View

23

xibXML file containing UI layout for a screenGenerated by Interface Builder

nibbinary version of xib used in compiled app

Normally defined in xib & nib files


Interface Builder - Xcode 4

24


Interface Builder - Xcode 3

25


Declaring connections in Code

26

@interface CounterViewController : UIViewController { int * count;}@property (nonatomic, retain) IBOutlet UILabel * countDisplay;

- (IBAction) increasePressed;- (IBAction) decreasePressed;@end

Controller

+IBActions

IBOutlets-

2

View

increasedPresseddecreasedPressed

countDisplay


Making Connections - Xcode 4

27


You need to right-click on the button and drag to the Controller.h file to add a new Action/Outlet. If you don't have a 2 button mouse you need to control-click.

Connecting to Existing Action/Outlet

28


Right-click (or control click) on button and drag to the file's Owner to connect to an existing Action/outlet

Making the Connection in Interface Builder

29


The Connections

30

IBActionMethod in controllerConnect UI event to methodUI element triggers methodTypedef - is void

IBOutletInstance variable in controllerReference ti UI elementEmpty typedef


31

Demo


32


#import

@interface CounterViewController : UIViewController { int count;}@property (nonatomic, retain) IBOutlet UILabel * countDisplay;

- (IBAction) increasePressed;- (IBAction) decreasePressed;

@end



33

#import "CounterViewController.h"@implementation CounterViewController@synthesize countDisplay;

- (void) displayCount { [countDisplay setText:[NSString stringWithFormat:@"%i", count]];}

- (IBAction) increasePressed { count++; [self displayCount];}

- (IBAction) decreasePressed { count--; [self displayCount];}

- (void)dealloc { [super dealloc]; [countDisplay release];}@end


CounterViewController

34

No changes made to generated code


Action Method options

35

- (void)actionMethod; - (void)actionMethod:(id)sender; - (void)actionMethod:(id)sender withEvent:(UIEvent *)event;


- (void)actionMethod;

36

When no data is needed from UI element

- (IBAction) increasePressed { count++; [self displayCount];}


- (void)actionMethod:(id)sender;

37

When need data from senderWhen need to interact with sender

- (IBAction) increasePressed: (id) sender { UIButton * buttonPressed = (UIButton*) sender; if ([buttonPressed.titleLabel.text isEqualToString: @"+"]) { count++; [self displayCount]; if (count > 5) { [buttonPressed setTitle: @"X" forState: UIControlStateNormal]; } }}


- (void)actionMethod:(id)sender withEvent:(UIEvent *)event;

38

- (IBAction) increasePressed: (id) sender withEvent: (UIEvent *) event { NSSet * touches = [event allTouches]; count = count + [touches count]; [self displayCount];}

Event contains information about the UI event


Where is the Model?

39

View

Controller

Modelint count was model

Used default initial value


Counter Model

40

@interface Counter : NSObject { int count;}

-(void) increase;-(void) decrease;-(int) count;

@end

@implementation Counter

-(void) increase { count++; }

-(void) decrease { count--; }

-(int) count { return count; }

- (id) init { if (self = [super init]) { count = 0; } return self;}@end



41

#import #import "Counter.h"

@interface CounterViewController : UIViewController { Counter * count;}@property (nonatomic, retain) IBOutlet UILabel * countDisplay;



Using the model

42

- (void) displayCount { [countDisplay setText:[NSString stringWithFormat:@"%i", [count count]]];}

- (IBAction) increasePressed { [count increase]; [self displayCount];}

- (IBAction) decreasePressed { [count decrease]; [self displayCount];}


Creating & releasing the Model

43

- (void)dealloc { [super dealloc]; [countDisplay release]; [count release];}

- (void) awakeFromNib { NSLog(@"awakefromNib"); count = [Counter new];}


App life cycle

44


diagram from "iPhone Application Programming Guide"

Starting points for your app code

45

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *) launchOptions

App Delegate

- (id) initWithCoder:(NSCoder *) aDecoder- (id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil- (void) awakeFromNib- (void) viewDidLoad

Controller


Creating Views in code

46

When count >=3 Create & display "Done"



47

#import #import "Counter.h"

@interface CounterViewController : UIViewController { Counter * count;}@property (nonatomic, retain) IBOutlet UILabel * countDisplay;@property (nonatomic, retain) IBOutlet UILabel * doneLabel;



CounterViewController.m

48

#import "CounterViewController.h"

@implementation CounterViewController

@synthesize countDisplay;@synthesize doneLabel;

- (void) displayCount { [countDisplay setText:[NSString stringWithFormat:@"%i", [count count]]];}



49

- (IBAction) increasePressed { [count increase]; [self displayCount]; if ([count count] >= 3) { [self displayDoneLabel]; }}

- (void) displayDoneLabel { if (doneLabel == nil) { [self createDoneLabel]; } else { doneLabel.hidden = NO; }}



50

- (void) createDoneLabel { CGRect frame = CGRectMake(115, 300, 90, 30); [self setDoneLabel: [[UILabel alloc] initWithFrame:frame]]; doneLabel.textAlignment = UITextAlignmentCenter; doneLabel.font = [UIFont fontWithName:@"Verdana" size:24]; doneLabel.text = @"Done"; [self.view addSubview:doneLabel];}



51

- (IBAction) decreasePressed { [count decrease]; [self displayCount]; if ([count count] < 3) { doneLabel.hidden = YES; }}


Documents

CS 696 Mobile Application Development Fall Semester, 2011 ...First Example 3 Counter + increases count - decrease count Thursday, September 15, 2011