From Hello World to Finished App. raywenderlich.com

Transcription

1 From Hello World to Finished App

2 Why Learn ios? - Strong demand - Motivating - App Store - It s fun!

3 What s This All About? - One Day Crash Course - For beginners & intermediates - Making apps with UIKit - ios4 - Lots of demos - Hands-on focus

4 After Today You ll Have... - Written 3 ios apps! - From scratch! - That are actually useful! - Using common APIs! - Both iphone and ipad XP!

5 Non-Goals - Game Programming - Learning everything there is to know :]

6 Oh, and Epic Loot! - Epic loot to give away! - Thanks to Addison-Wesley! - To enter, send any Tweet with the following words before the Hello, ipad talk: - source: user from sxc.hu - Or... reach Uber Haxx0r level!

7 Hands-On Labs - Each section has a hands-on lab - Split into two parts: - Tutorial Walkthrough - Uber Haxx0r Challenge - 1st Uber Haxx0r at each challenge wins epic loot! - Max 1 prize :]

8 Today s Schedule

9 Today s Schedule - Morning: - Objective-C Crash Course - Hello, iphone! - Common UIKit Controls

10 Today s Schedule - Morning: - Objective-C Crash Course - Hello, iphone! - Common UIKit Controls - Lunch!

11 Today s Schedule - Morning: - Objective-C Crash Course - Hello, iphone! - Common UIKit Controls - Afternoon: - Table Views and Navigation - Saving Data - Hello, ipad! - Lunch!

12 Today s Schedule - Morning: - Objective-C Crash Course - Hello, iphone! - Common UIKit Controls - Lunch! - Afternoon: - Table Views and Navigation - Saving Data - Hello, ipad! - Beer!

13 About Me - Ray Wenderlich - Indie dev for ~2 years - Writes ios tutorials -

14 Objective-C Crash Course

15 What We ll Cover - Getting Started - Creating a Class - Memory Management - Objective-C Properties - Useful Classes

16 Demo: Getting Started - Start up Xcode - From the menu, choose File\New\New Project - Choose ios\application\view-based Application, click Next - Enter HelloObjC for Product Name, click Next - Choose where to save and click Create

17 Demo: Getting Started - Click Run - Shows just an empty. - Open HelloObjCAppDelegate.m - Add some test code like so: - (BOOL)application:(UIApplication *)application didfinishlaunchingwithoptions:(nsdictionary *)launchoptions { // Add test code inside here, it will run on startup! :D NSLog(@"Hello, console!"); } // Override point for customization after application launch. self.window.rootviewcontroller = self.viewcontroller; [self.window makekeyandvisible]; return YES;

18 Demo: Getting Started

19 Creating a Class source: xkcd

20 Creating a Class - Class Name: DateCalculator - Get and set your age - Have a method to return whether you should date someone given her age Hayden Panettiere from Heroes - too Young to Date? She s 22! source: Glenn Francis

21 Objective-C Cheat Sheet

22 Demo: Creating a Class - Control-click HelloObjC group - Select New File... - Select ios\cocoa Touch \Objective-C class, click Next - Enter Subclass of NSObject, click Next - Type DateCalculator.m, click Save

23 Demo: Creating a Class // DateCalculator.h #import DateCalculator : NSObject { float _myage; } - (void)setmyage:(float)myage; - (float)myage; -

24 Demo: Creating a Class // DateCalculator.m #import DateCalculator - (void)setmyage:(float)myage { _myage = myage; } - (float)myage { return _myage; } - (BOOL)shouldIDateIfHerDateIs:(float)herAge { float minagetodate = _myage/2 + 7; return herage > minagetodate;

25 Demo: Creating a Class #import "DateCalculator.h" DateCalculator * calc = [[DateCalculator alloc] init]; [calc setmyage:31]; BOOL shoulddate = [calc shouldidateifherdateis:22]; if (shoulddate) { NSLog(@"It's OK to date Hayden!"); } else { NSLog(@"You shouldn't date Hayden, you old man!"); } [calc release];

26 Memory Management

27 Memory Management - All Objective-C classes should subclass NSObject - NSObject classes are reference counted - When reference count == 0, memory released

28 Memory Management - All Objective-C classes should subclass NSObject - NSObject classes are reference counted - When reference count == 0, memory released - ARC automatically manages ref count

29 Memory Management - All Objective-C classes should subclass NSObject - NSObject classes are reference counted - When reference count == 0, memory released - ARC automatically manages ref count - Managing ref count: - init: reference count = 1 - release: reference count -- - retain: reference count ++ - autorelease: reference count -- (later on)

30 Memory Management - Methods beginning with init or copy return objects with ref count of 1 - You need to release these when you re done NSArray *myarray = [[NSArray alloc] initwithobjects:obj1, obj2, nil]; // Use myarray, and when done... [myarray release]; - Anything else returns autorelease objects - You need to retain these if you don t want them to go away NSArray *myarray = [NSArray arraywithobjects:obj1, obj2, nil]; // You can use this as much as you want until the next run loop. // If you need if after that, you need to retain it... [myarray retain]; // And when you're done... [myarray release];

31 Objective-C Properties - Writing getters and setters is very common - Writing them correctly can be difficult - Objective-C properties make writing getters/ setters easier and safer

32 Useful Classes - NSString - Collections: - NSArray - NSDictionary - Mutable vs. Immutable - NSValue

33 Objective-C Cheat Sheet

34 Demo: Adding Properties // In (assign) float myage; // Delete previously written getter/setter // In myage = _myage; // Delete previously written getter/setter

35 Demo: Adding Custom Init // In DateCalculator.h // NSString * _myname; (retain) NSString * myname; - (id)initwithmyname:(nsstring *)myname andmyage:(int)myage; // In myname = _myname; - (id)initwithmyname:(nsstring *)myname andmyage:(int)myage { if ((self = [super init])) { self.myname = myname; self.myage = myage; } return self; } - (void)dealloc { [_myname release]; [super dealloc]; }

36 Demo: NSString, NSArray // Replace test code in HelloObjCAppDelegate.m with this NSArray * girls = nil]; NSArray * ages = [NSArray arraywithobjects: [NSNumber numberwithfloat:22], [NSNumber numberwithfloat:27], [NSNumber numberwithfloat:36], nil]; DateCalculator * calc = [[DateCalculator alloc] initwithmyname:@"ray" andmyage:31]; for (int i = 0; i < girls.count; ++i) { NSString *girl = [girls objectatindex:i]; NSNumber *age = [ages objectatindex:i]; BOOL shoulddate = [calc shouldidateifherdateis:age.floatvalue]; NSString *message; if (shoulddate) { message = [NSString stringwithformat:@"%@, it is OK to date %@.", calc.myname, girl]; } else { message = [NSString stringwithformat:@"%@, you are too old to date %@!", calc.myname, girl]; } NSLog(@"%@", message); } [calc release];

37 Lab Time! source: hdwarriors.com

38 Hello, iphone!

39 What We ll Cover - Xcode layout - App Structure - Interface Builder - Connecting controls to properties - Connecting actions to methods - Xcode s debugger

40 Demo: Xcode Layout Run, test, profile, or analyze app (hold down for options) Status display Just Standard editor Turn on Assistant editor Stop running app Run in iphone sim, ipad sim, or device? Groups & Files Standard editor Assistant editor Change visible file

41 Demo: Xcode Layout Turn on Navigator Turn on Debug area Turn on Utilities Navigator Debug Area Utilities Inspectors Libraries

42 Demo: Xcode Layout

43 App Structure - We chose View-Based Application Template - It made us: - An application delegate - A main Window - A single view controller - A single (empty) view

44 App Structure Main Window (this example: in MainWindow.xib)

45 App Structure Main Window (this example: in MainWindow.xib) subview View (this example: in HelloObjCViewController.xib )

46 App Structure Main Window (this example: in MainWindow.xib) subview View (this example: in HelloObjCViewController.xib ) subview Label (this example: in HelloObjCViewController.xib )

47 App Structure Main Window (this example: in MainWindow.xib) subview View Controller (this example: in HelloObjCViewController.h/m ) View (this example: in HelloObjCViewController.xib ) subview Label (this example: in HelloObjCViewController.xib )

48 App Structure Main Window (this example: in MainWindow.xib) subview View (this example: in HelloObjCViewController.xib ) references View Controller (this example: in HelloObjCViewController.h/m ) subview Label (this example: in HelloObjCViewController.xib )

49 App Structure Main Window (this example: in MainWindow.xib) subview View (this example: in HelloObjCViewController.xib ) subview references View Controller (this example: in HelloObjCViewController.h/m ) Model (this example: in DateCalculator.h/m ) Label (this example: in HelloObjCViewController.xib )

50 App Structure Main Window (this example: in MainWindow.xib) subview View (this example: in HelloObjCViewController.xib ) subview references View Controller (this example: in HelloObjCViewController.h/m ) references Model (this example: in DateCalculator.h/m ) Label (this example: in HelloObjCViewController.xib )

51 View Lifecycle - Methods in UIViewController: - viewdidload - viewwillappear - viewdidappear - viewwilldisappear - viewdiddisappear - viewdidunload

52 View Lifecycle - Methods in UIViewController: - viewdidload - viewwillappear Called first time viewcontroller s view property accessed. Important: can be called more than once! - viewdidappear - viewwilldisappear - viewdiddisappear - viewdidunload

53 View Lifecycle - Methods in UIViewController: - viewdidload - viewwillappear - viewdidappear - viewwilldisappear Called first time viewcontroller s view property accessed. Important: can be called more than once! Often a good place to populate views from model. - viewdiddisappear - viewdidunload

54 View Lifecycle - Methods in UIViewController: - viewdidload - viewwillappear - viewdidappear - viewwilldisappear - viewdiddisappear - viewdidunload Called first time viewcontroller s view property accessed. Important: can be called more than once! Often a good place to populate views from model. Happens when view controller is no longer visible, and a memory warning occurs.

55 Demo: Interface Builder Ref to the object that loads the XIB These get created when XIB loaded Inspector for selection, has multiple tabs Interface Builder XIB (Xcode Interface Builder) Main view Subview Expands pane Assistant editor set to automatic, so shows current view controller Object library

56 Demo: Interface Builder 1) Assistant editor set to automatic, so shows current view controller 2) Control-drag from label to right 3) Enter name of outlet, and click Connect

57 Demo: What It Did // HelloObjCViewController.h // Added an instance variable UILabel *resultlabel; } Control-click to see IBOutlets for View Controller // Added a property after // marked it as IBOutlet and (nonatomic, retain) IBOutlet UILabel *resultlabel; // HelloObjCViewController.m // Synthesized resultlabel; // Released label in dealloc [resultlabel release]; Can drag from this circle to the UILabel to connect. // Set label to nil (effectively releasing) in viewdidunload [self setresultlabel:nil];

58 Demo: Interface Builder 1) Assistant editor set to automatic, so shows current view controller 2) Control-drag from button to right 3) Set Connection to Action 4) Type in name of method to create and click Connect

59 Demo: What It Did // HelloObjCViewController.h Control-click to see Actions for Button // Declared a new method, marked as IBAction - (IBAction)calculateTapped:(id)sender; // HelloObjCViewController.m // Added stub for new method - (IBAction)calculateTapped:(id)sender { } Can drag from this circle to the File s Owner. Will show any methods marked as IBAction in View Controller and you can connect.

60 Demo: Implementation // HelloObjCViewController.h // Add at top of file #import "DateCalculator.h" // Add DateCalculator * _datecalculator; // (retain) DateCalculator * datecalculator; // HelloObjCViewController.m #import HelloObjCViewController // HelloObjCViewController.m // datecalculator = _datecalculator; // Release datecalculator in dealloc AND viewdidunload [_datecalculator release]; // Uncomment and implement viewdidload - (void)viewdidload { self.datecalculator = [[[DateCalculator alloc] initwithmyname:@"ray" andmyage:31] autorelease]; [super viewdidload]; } // Add to viewdidunload self.datecalculator = nil; // Implement calculatetapped - (IBAction)calculateTapped:(id)sender { BOOL shoulddate = [_datecalculator shouldidateifherdateis:22]; NSString *message; if (shoulddate) { message = [NSString stringwithformat:@"%@, it is OK to date her.", _datecalculator.myname]; } else { message = [NSString stringwithformat:@"%@, you are too old to date her!", _datecalculator.myname]; } resultlabel.text = message; }

61 Demo: Xcode s Debugger Click in margin to set breakpoints Toggles Debugger Call Stack Continue Step Over Step Into & Out Expand self to see instance variables Shows console + variables

62 Lab Time!

63 Common UIKit Controls

64 What We ll Cover - Useful UIKit Controls - Protocols and Delegates - MadLibs Demo - Device Orientation

65 UILabel - Set text with text property - Particularly useful settings: - Changing alignment - Lines - Changing font - Adjust to fit - Shadow

66 UITextView - Set with text property - Good for multi-line text - Also editable and scrollable! - Particularly useful settings: - Auto-detect phone # s, addresses, etc. - Scroll settings

67 UIButton - To get callback on click: connect to Touch Up Inside action - To set custom image for button: Type->Custom, change Image - Buttons have different states - Default, Highlighted, Selected, Disabled - Can have different titles/images/etc. for each state

68 UISlider - To get callback on slider value changing: connect to Value Changed action - To get current value of slider: value property - Particularly useful settings: - min/max/initial values - min/max images

69 UISegmentedControl - To get selected index: selectedsegmentindex property - Can set up segments directly in Interface Builder

70 UIImageView - Simply set the image - Programatic change via image property - Change the mode to affect the scaling/positioning behavior: - Scale to Fill - Aspect Fit/Aspect Fill - Center/Top/Left/etc.

71 UITextField - To get text, use text property - Particularly useful settings: - Clear Button - Capitalize/Correction - Keyboard/Return Key - By default, keyboard will not disappear when the return key is tapped!

72 Protocols and Delegates

73 Protocols and Delegates - You already know how to connect actions on a Control to methods - Like Touch Up Inside on a Button - But sometimes actions aren t enough!

74 Protocols and Delegates - You already know how to connect actions on a Control to methods - Like Touch Up Inside on a Button - But sometimes actions aren t enough! - For more info: - View controller implements an interface (called a protocol) - Set View Controller as delegate of control

75 Protocols and Delegates - You already know how to connect actions on a Control to methods - Like Touch Up Inside on a Button - But sometimes actions aren t enough! - For more info: - View controller implements an interface (called a protocol) - Set View Controller as delegate of control

76 Protocols and Delegates - You already know how to connect actions on a Control to methods - Like Touch Up Inside on a Button - But sometimes actions aren t enough! - For more info: - View controller implements an interface (called a protocol) - Set View Controller as delegate of control Control-click to see outlets for text field. One outlet is its delegate!

77 Protocols and Delegates - You already know how to connect actions on a Control to methods - Like Touch Up Inside on a Button - But sometimes actions aren t enough! - For more info: - View controller implements an interface (called a protocol) - Set View Controller as delegate of control Control-click to see outlets for text field. One outlet is its delegate! Drag from this circle to File s Owner to set the View Controller as the Text Field s delegate.

78 Protocols and - (BOOL)textFieldShouldBeginEditing:(UITextField *)textfield; - (void)textfielddidbeginediting:(uitextfield *)textfield; - (BOOL)textFieldShouldEndEditing:(UITextField *)textfield; - (void)textfielddidendediting:(uitextfield *)textfield; - (BOOL)textField:(UITextField *)textfield shouldchangecharactersinrange: (NSRange)range replacementstring:(nsstring *)string; - (BOOL)textFieldShouldClear:(UITextField *)textfield; - UITextField : UIControl <UITextInputTraits, NSCoding> { id<uitextfielddelegate> _delegate; // Stuff... }

79 Protocols and - (BOOL)textFieldShouldBeginEditing:(UITextField *)textfield; - (void)textfielddidbeginediting:(uitextfield *)textfield; - (BOOL)textFieldShouldEndEditing:(UITextField *)textfield; - (void)textfielddidendediting:(uitextfield *)textfield; - (BOOL)textField:(UITextField *)textfield shouldchangecharactersinrange: (NSRange)range replacementstring:(nsstring *)string; - (BOOL)textFieldShouldClear:(UITextField *)textfield; - (BOOL)textFieldShouldReturn:(UITextField Declare a protocol. Specify required and optional UITextField : UIControl <UITextInputTraits, NSCoding> { id<uitextfielddelegate> _delegate; // Stuff... }

80 Protocols and - (BOOL)textFieldShouldBeginEditing:(UITextField *)textfield; - (void)textfielddidbeginediting:(uitextfield *)textfield; - (BOOL)textFieldShouldEndEditing:(UITextField *)textfield; - (void)textfielddidendediting:(uitextfield *)textfield; - (BOOL)textField:(UITextField *)textfield shouldchangecharactersinrange: (NSRange)range replacementstring:(nsstring *)string; - (BOOL)textFieldShouldClear:(UITextField *)textfield; - (BOOL)textFieldShouldReturn:(UITextField Declare a protocol. Specify required and optional UITextField : UIControl <UITextInputTraits, NSCoding> { id<uitextfielddelegate> _delegate; // Stuff... } This class stores a reference to a class that implements UITextFieldDelegate.

81 Protocols and MadLibsViewController : UIViewController <UITextFieldDelegate> { // Stuff... } - (BOOL)textFieldShouldReturn:(UITextField *)textfield { } int i = [_textfields indexofobject:textfield]; if (i < [_textfields count] - 1) { UITextField *nexttextfield = [_textfields objectatindex:i+1]; [nexttextfield becomefirstresponder]; } else { [textfield resignfirstresponder]; } return TRUE;

82 Protocols and MadLibsViewController : UIViewController <UITextFieldDelegate> { // Stuff... } Mark the class as implementing the UITextFieldDelegate. - (BOOL)textFieldShouldReturn:(UITextField *)textfield { } int i = [_textfields indexofobject:textfield]; if (i < [_textfields count] - 1) { UITextField *nexttextfield = [_textfields objectatindex:i+1]; [nexttextfield becomefirstresponder]; } else { [textfield resignfirstresponder]; } return TRUE;

83 Protocols and MadLibsViewController : UIViewController <UITextFieldDelegate> { // Stuff... } Mark the class as implementing the UITextFieldDelegate. - (BOOL)textFieldShouldReturn:(UITextField *)textfield { } int i = [_textfields indexofobject:textfield]; if (i < [_textfields count] - 1) { UITextField *nexttextfield = [_textfields objectatindex:i+1]; [nexttextfield becomefirstresponder]; } else { [textfield resignfirstresponder]; } return TRUE; Implement any methods you care about. Since you set the view controller as the text field s delegate in Interface Builder, this will be called!

84 Protocols and MadLibsViewController : UIViewController <UITextFieldDelegate> { // Stuff... } Mark the class as implementing the UITextFieldDelegate. Move focus to nexttextfield Hide keyboard - (BOOL)textFieldShouldReturn:(UITextField *)textfield { } int i = [_textfields indexofobject:textfield]; if (i < [_textfields count] - 1) { UITextField *nexttextfield = [_textfields objectatindex:i+1]; [nexttextfield becomefirstresponder]; } else { [textfield resignfirstresponder]; } return TRUE; Implement any methods you care about. Since you set the view controller as the text field s delegate in Interface Builder, this will be called!

85 Demo: Mad Libs - Layout interface - Connect controls to outlets - Text fields - Segmented Control - Slider - Slider Label - Text Area

86 Demo: Mad Libs - Connect TouchUpInside on Button to method - Connect ValueChanged on Slider to method - Set Slider attributes - (IBAction)sliderValueChanged:(id)sender { numberlabel.text = [NSString stringwithformat:@"%d", (int) slider.value]; }

87 Demo: Mad Libs - Set the delegate of all 4 text fields to File s Owner (the View Controller)

88 Demo: Mad Libs // MadLibsViewController.h // to mark as implementing MadLibsViewController : UIViewController <UITextFieldDelegate> { // Add NSArray * _textfields; // (retain) NSArray * textfields; // MadLibsViewController.m // textfields = _textfields; // Add in dealloc [_textfields release]; // Uncomment viewdidload and add the following self.textfields = [NSArray arraywithobjects:pasttenseverb, singularnoun, pluralnoun, phrase, nil]; // Add in viewdidunload [self settextfields:nil]; // Add new method - (BOOL)textFieldShouldReturn:(UITextField *)textfield { } int i = [_textfields indexofobject:textfield]; if (i < [_textfields count] - 1) { UITextField *nexttextfield = [_textfields objectatindex:i+1]; [nexttextfield becomefirstresponder]; } else { [textfield resignfirstresponder]; } return TRUE;

89 Demo: Mad Libs - (IBAction)goTapped:(id)sender { NSString *placestring; if (place.selectedsegmentindex == 0) { placestring } else { placestring } } result.text = [NSString day, at %@ a %@ %@ %@ %@ and said, %@!", placestring, singularnoun.text, pasttenseverb.text, numberlabel.text, pluralnoun.text, phrase.text];

90 Device Orientation - iphone supports four orientations: - Portrait, Portrait Upside Down - Landscape Left, Landscape Right - Your app can (and should) reorient your views to support orientation changes - With Interface Builder, it s easy!

91 Demo: Device Orientation - (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation { return YES; }

92 Lab Time!

93 Table Views and Navigation

94 What We ll Cover - View-Based App Template Walkthrough - Navigation Controllers - Table Views - UIImagePickerController - 5-Minute Break - Demo App

95 Demo: View-Based App Template Walkthrough // main.m (under Supporting Files) Last parameter is nil... #import <UIKit/UIKit.h> int main(int argc, char *argv[]) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; int retval = UIApplicationMain(argc, argv, nil, nil); [pool release]; return retval; } So look in the Info.plist and load this XIB/NIB!

96 Demo: View-Based App Template Walkthrough File s Owner is UIApplication An instance of the App Delegate, View Controller, and Window are created when this XIB is loaded App Delegate has outlets connected to the view controller and window that were created App Delegate is the delegate of File s Owner (UIApplication)

97 Demo: View-Based App Template Walkthrough // MadLibsAppDelegate.m - (BOOL)application:(UIApplication *)application didfinishlaunchingwithoptions: (NSDictionary *)launchoptions { self.window.rootviewcontroller = self.viewcontroller; [self.window makekeyandvisible]; return YES; } Sets which View Controller shows up on startup. Can set this in Interface Builder too!

98 Navigation Controllers - Provides easy way to drill down to different view controllers - Set up with root view controller - Stack based model - pushviewcontroller - popviewcontroller

99 Navigation Controllers - UIViewControllers have special properties to access parts of their Navigation Controller: - self.navigationcontroller - self.navigationitem.leftbarbuttonitem - self.navigationitem.title - self.navigationitem.rightbarbuttonitem - And more!

100 Introducing Scary Bugs

101 Demo: Navigation Controllers

102 Demo: Navigation Controllers

103 Demo: Navigation Controllers

104 Demo: Navigation Controllers A Navigation Controller is the Window s rootviewcontroller

105 Demo: Navigation Controllers A Navigation Controller is the Window s rootviewcontroller The top thing in the Navigation Controller Stack is a view controller called RootViewController (confusing name I know)

106 Demo: Navigation Controllers A Navigation Controller is the Window s rootviewcontroller The top thing in the Navigation Controller Stack is a view controller called RootViewController (confusing name I know) Sets Class in Identity Inspector, and NIB name in Attributes Inspector

107 Demo: Navigation Controllers A Navigation Controller is the Window s rootviewcontroller The top thing in the Navigation Controller Stack is a view controller called RootViewController (confusing name I know) Sets Class in Identity Inspector, and NIB name in Attributes Inspector Want a different View Controller first? Just change these!

108 Demo: Navigation Controllers The template s made the RootViewController.xib a UITableViewController (more on this later)

109 Demo: Navigation Controllers

110 Demo: Navigation Controllers

111 Demo: Navigation Controllers // DetailViewController.m // Add inside viewdidload self.navigationitem.title self.navigationitem.rightbarbuttonitem = [[[UIBarButtonItem alloc] initwithtitle:@"clickme" style:uibarbuttonitemstylebordered target:self action:@selector(clickmetapped:)] autorelease]; // Add new method - (void)clickmetapped:(id)sender { // Just for demonstration purposes NSLog(@"You clicked me!"); [self.navigationcontroller popviewcontrolleranimated:yes]; }

112 Demo: Navigation Controllers // RootViewController.h #import <UIKit/UIKit.h> #import RootViewController : UITableViewController { DetailViewController * _detailviewcontroller; (retain) DetailViewController * // RootViewController.m // detailviewcontroller = _detailviewcontroller; // Add inside viewdidload self.navigationitem.title // For testing purposes, replace return statement in tableview:numberofrowsinsection with this return 10; // For testing purposes, add the following in tableview:cellforrowatindexpath before the return statement cell.textlabel.text = [NSString stringwithformat:@"row %d", indexpath.row]; // Add inside tableview:didselectrowatindexpath if (_detailviewcontroller == nil) { self.detailviewcontroller = [[[DetailViewController alloc] initwithnibname:nil bundle:nil] autorelease]; } [self.navigationcontroller pushviewcontroller:_detailviewcontroller animated:yes]; // Add in dealloc [_detailviewcontroller release];

113 Table Views - Scrollable list of items - Each row: table view cell - Optimized to reuse cells for speed - To use, implement UITableViewDelegate and UITableViewDataSource

114 Table Views plain grouped

115 Table Views - tableview:numberofsectionsintableview - tableview:titleforheaderinsection - tableview:numberofrowsinsection - tableview:cellforrowatindexpath - tableview:didselectrowatindexpath

116 Table Views - Built-in cell styles: - UITableViewCellStyleDefault - UITableViewCellStyleSubtitle - UITableViewCellStyleValue1 - UITableViewCellStyleValue2 - Built-in cell properties: - textlabel, detailtextlabel, imageview

117 Demo: Table Views - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableview { return 1; } - (NSInteger)tableView:(UITableView *)tableview numberofrowsinsection: (NSInteger)section { return 10; } - (void)tableview:(uitableview *)tableview didselectrowatindexpath: (NSIndexPath *)indexpath { if (_detailviewcontroller == nil) { self.detailviewcontroller = [[[DetailViewController alloc] initwithnibname:nil bundle:nil] autorelease]; } [self.navigationcontroller pushviewcontroller:_detailviewcontroller animated:yes]; }

118 Demo: Table Views - (UITableViewCell *)tableview:(uitableview *)tableview cellforrowatindexpath: (NSIndexPath *)indexpath { static NSString *CellIdentifier As cells scroll offscreen, they are reused! Take care! UITableViewCell *cell = [tableview dequeuereusablecellwithidentifier:cellidentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initwithstyle:uitableviewcellstylevalue2 reuseidentifier:cellidentifier] autorelease]; } } // Configure the cell. cell.textlabel.text Norris"; cell.imageview.image = [UIImage imagenamed:@"icon.png"]; cell.detailtextlabel.text return cell;

119 UIImagePickerController - Easy way to let users choose/take photos (set sourcetype) - Create with alloc/init, set sourcetype - Display with presentmodalviewcontroller - Set self as delegate, receive didfinishpickingmediawithinfo callback

120 Demo: Scary Bugs #import ScaryBug : NSObject { NSString * _name; UIImage * _image; float _howscary; (retain) NSString * (retain) UIImage * (assign) float howscary; - (id)initwithname:(nsstring *)name image:(uiimage *)image howscary: #import name = image = howscary = _howscary; - (id)initwithname:(nsstring *)name image: (UIImage *)image howscary:(float)howscary { if ((self = [super init])) { self.name = name; self.image = image; self.howscary = howscary; } return self; } - (void)dealloc { [_name release]; [_image release]; [super dealloc];

121 Demo: Scary Bugs // ScaryBugsAppDelegate.m // At top of file #import "RootViewController.h" #import "ScaryBug.h" // At top of application:didfinishlaunchingwithoptions ScaryBug * centipede = [[[ScaryBug alloc] initwithname:@"centipede" image: [UIImage imagenamed:@"centipede.jpg"] howscary:3.0] autorelease]; ScaryBug * ladybug = [[[ScaryBug alloc] initwithname:@"ladybug" image: [UIImage imagenamed:@"ladybug.jpg"] howscary:1.0] autorelease]; ScaryBug * potatobug = [[[ScaryBug alloc] initwithname:@"potato Bug" image: [UIImage imagenamed:@"potatobug.jpg"] howscary:4.0] autorelease]; ScaryBug * wolfspider = [[[ScaryBug alloc] initwithname:@"wolf Spider" image: [UIImage imagenamed:@"wolfspider.jpg"] howscary:5.0] autorelease]; NSMutableArray * bugs = [NSMutableArray arraywithobjects: centipede, ladybug, potatobug, wolfspider, nil]; RootViewController * rootviewcontroller = [self.navigationcontroller.viewcontrollers objectatindex:0]; rootviewcontroller.bugs = bugs;

122 Demo: Scary Bugs // RootViewController.h // Add at top of file #import "ScaryBug.h" // Add NSMutableArray * _bugs; } // (retain) NSMutableArray * bugs; // RootViewController.m // bugs = _bugs; // Inside numberofrowsinsection return _bugs.count; // Add inside viewwillappear [self.tableview reloaddata]; // Inside cellforrowatindexpath ScaryBug * bug = [_bugs objectatindex:indexpath.row]; cell.textlabel.text = bug.name; cell.imageview.image = bug.image; // Inside didselectrowatindexpath ScaryBug * bug = [_bugs objectatindex:indexpath.row]; _detailviewcontroller.bug = bug; // Add in dealloc [_bugs release];

123 Demo: Scary Bugs #import <UIKit/UIKit.h> #import DetailViewController : UIViewController { ScaryBug * _bug; (retain) ScaryBug *

124 Demo: Scary Bugs // DetailViewController.m // bug = _bug; // Add inside dealloc [_bug release]; // Add new method - (void)viewwillappear:(bool)animated { _textfield.text = _bug.name; _imageview.image = _bug.image; _slider.value = _bug.howscary; } // DetailViewController.h // Mark as implementing these DetailViewController : UIViewController <UIImagePickerControllerDelegate, UITextFieldDelegate> // Add inside textfieldeditingchanged _bug.name = _textfield.text; // Add inside slidervaluechanged _bug.howscary = _slider.value; // Add inside buttontapped UIImagePickerController * picker = [[[UIImagePickerController alloc] init] autorelease]; picker.sourcetype = UIImagePickerControllerSourceTypePhotoLibrary; picker.allowsediting = NO; picker.delegate = self; [self presentmodalviewcontroller:picker animated:yes]; // Add new methods -(void)imagepickercontroller:(uiimagepickercontroller *)picker didfinishpickingmediawithinfo: (NSDictionary *)info { UIImage *image = [info objectforkey:uiimagepickercontrolleroriginalimage]; _bug.image = image; [self dismissmodalviewcontrolleranimated:yes]; } -(BOOL)textFieldShouldReturn:(UITextField *)textfield { [_textfield resignfirstresponder]; return YES; }

125 Lab Time!

126 Saving Data

127 What We ll Cover - Working with paths and files - Survey of ways to save your app s data - Demo: using some of the simplest ways in Scary Bugs

128 Many Ways to Save Data - NSData/NSString - fread/fwrite - SQLite - Core Data - User Defaults - Property List Serialization - NSCoding

129 Many Ways to Save Data - NSData/NSString - fread/fwrite - User Defaults - Property List Serialization - NSCoding - SQLite - Core Data Which to choose?!

130 Getting Paths to Files - For files included in your Xcode project: NSString * path = [[NSBundle mainbundle] pathforresource:@"centipede" oftype:@"jpg"]; - But be careful: read-only!

131 Getting Paths to Files - NSSearchPathForDir ectoriesindomains - NSDocumentDirectory (file sharing enabled) NSArray * docdirs = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES); NSString *docdir = [docdirs objectatindex:0]; - NSLibraryDirectory (appspecific contents don t want shared) - NSCachesDirectory (not backed up)

132 Getting Paths to Files - NSString has many helpful methods related to paths - stringbyappendingpathcomponent - lastpathcomponent - pathextension - stringbydeletinglastpathcomponent NSString *fullpath = [docdir stringbyappendingpathcomponent:@"mydoc.txt"];

133 Reading Files - NSData gets raw bytes: NSData * data = [NSData datawithcontentsoffile:path]; if (data) { void * buffer = [data bytes]; NSUInteger bufferlen = [data length]; } - Or can get as NSString: NSError * error; NSString * string = [NSString stringwithcontentsoffile:path encoding:nsutf8stringencoding error:&error]; if (string) { NSLog(@"%@", string); }

134 Writing Files - Can also write NSData: BOOL success = [data writetofile:path atomically:yes]; - Or NSString: NSError *error; BOOL success = [string writetofile:path atomically:yes encoding:nsutf8stringencoding error:&error];

135 Reading/Writing Files - NSData/NSString methods are convenient, but read/write entire files at once - Can be a problem for large files (memory, speed). - Want to read/write part at a time? - fread/fwrite - Higher-level APIs such as SQLite, Core Data

136 Managing Dirs and Files - NSFileManager - Access from anywhere - [[NSFileManager defaultmanager] - fileexistsatpath - contentsofdirectoryatpath:error - createdirectoryatpath:withintermed iatedirectories:attributes:error - removeitematpath:error

137 User Defaults - Easy way to store/read small amounts of data NSUserDefaults *userdefaults = [NSUserDefaults standarduserdefaults]; if ([userdefaults boolforkey:@"hasrunbefore"] == FALSE) { [userdefaults setbool:yes forkey:@"hasrunbefore"]; [userdefaults synchronize]; } NSLog(@"First time run!"); - Can store primitives: floats, doubles, integers, booleans - Also objects: NSString, NSNumber, NSDate, NSArray, NSDictionary, NSData, NSURL

138 Property List Serialization - Extremely easy to read/write/create, but limited NSString *path = [[NSBundle mainbundle] pathforresource:@"filename" oftype:@"plist"]; NSDictionary * plistdict = [NSDictionary dictionarywithcontentsoffile:path];

139 NSCoding - Easy way to serialize objects to NSData - Great for apps without heavy data requirements - (void) encodewithcoder:(nscoder *)acoder { [acoder encodeobject:_title forkey:@"title"]; [acoder encodefloat:_rating forkey:@"rating"]; } - (id) initwithcoder:(nscoder *)adecoder { NSString *title = [adecoder decodeobjectforkey:@"title"]; float rating = [adecoder decodefloatforkey:@"rating"]; return [self initwithtitle:title andrating:rating]; }

140 NSCoding - To save: - Serialize root object using NSKeyedUnarchiver NSData * data = [NSKeyedArchiver archiveddatawithrootobject:rootviewcontroller.bugs]; - Then write that data to a file - To load: - Read data from file - Then Unserialize root object using NSKeyedUnarchiver NSArray * bugsarray = [NSKeyedUnarchiver unarchiveobjectwithdata:data];

141 SQLite - SQLite is a library that reads a SQL database as a flat file - You can perform SQL queries on it - Command line tool to work with SQLite dbs: sqlite3 - Advantages: can easily retrieve subset of data, leverage power of DB engine, small learning curve if familiar with SQL dbs - Overall: Can be quick to learn, but Core Data usually better for-iphone-developers-creating-and-scripting

142 Core Data - Object graph management and persistence framework - Use a visual editor to design your object structure - Store your objects in a SQLite db - Cache objects as you read them out - Automatically pull related objects - Overall: usually best way, but learning curve and time to implement core-data-tutorial-getting-started

143 Demo: Simple Saving // ScaryBugsAppDelegate.m, in applicationdidfinishlaunching BOOL hasrunbefore = [[NSUserDefaults standarduserdefaults] boolforkey:@"hasrunbefore"]; if (!hasrunbefore) { [[NSUserDefaults standarduserdefaults] setbool:yes forkey:@"hasrunbefore"]; [[NSUserDefaults standarduserdefaults] synchronize]; } UIAlertView * alertview = [[[UIAlertView alloc] initwithtitle:@"welcome!" message:@"welcome to Scary Bugs!" delegate:nil cancelbuttontitle:nil otherbuttontitles:@"w00t", nil] autorelease]; [alertview show];

144 Demo: Simple Saving

145 Demo: Simple Saving

146 Demo: Simple Saving // ScaryBugsAppDelegate.m, in applicationdidfinishlaunching NSMutableArray * bugs = [NSMutableArray array]; NSString *path = [[NSBundle mainbundle] pathforresource:@"defaultbugs" oftype:@"plist"]; NSDictionary * plistdict = [NSDictionary dictionarywithcontentsoffile:path]; NSArray * plistbugs = [plistdict objectforkey:@"data"]; for (NSDictionary * bugdict in plistbugs) { NSString *name = [bugdict objectforkey:@"name"]; NSString *image = [bugdict objectforkey:@"image"]; NSNumber * howscarynumber = [bugdict objectforkey:@"howscary"]; ScaryBug * bug = [[[ScaryBug alloc] initwithname:name image:[uiimage imagenamed:image] howscary:howscarynumber.floatvalue] autorelease]; [bugs addobject:bug]; }

147 Demo: Simple Saving // ScaryBug : NSObject <NSCoding> { // ScaryBug.m - (void)encodewithcoder:(nscoder *)acoder { [acoder encodeobject:_name forkey:@"name"]; NSData *data = UIImagePNGRepresentation(_image); [acoder encodeobject:data forkey:@"image"]; [acoder encodefloat:_howscary forkey:@"howscary"]; } - (id)initwithcoder:(nscoder *)adecoder { NSString *name = [adecoder decodeobjectforkey:@"name"]; NSData *imagedata = [adecoder decodeobjectforkey:@"image"]; UIImage * image = [UIImage imagewithdata:imagedata]; float howscary = [adecoder decodefloatforkey:@"howscary"]; return [self initwithname:name image:image howscary:howscary]; }

148 Demo: Simple Saving // ScaryBugsAppDelegate.m, in applicationdidfinishlaunching NSMutableArray * bugs = [NSMutableArray array]; NSArray * docdirs = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES); NSString *docdir = [docdirs objectatindex:0]; NSString *bugspath = [docdir stringbyappendingpathcomponent:@"bugs.plist"]; if ([[NSFileManager defaultmanager] fileexistsatpath:bugspath]) { // File exists, let's load it NSData *data = [NSData datawithcontentsoffile:bugspath]; NSArray * bugsarray = [NSKeyedUnarchiver unarchiveobjectwithdata:data]; [bugs addobjectsfromarray:bugsarray]; } else { // Old code to load default bugs... }

149 Demo: Simple Saving // ScaryBugsAppDelegate.m - (void)applicationdidenterbackground:(uiapplication *)application { RootViewController * rootviewcontroller = [self.navigationcontroller.viewcontrollers objectatindex:0]; } NSArray * docdirs = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES); NSString *docdir = [docdirs objectatindex:0]; NSString *bugspath = [docdir stringbyappendingpathcomponent:@"bugs.plist"]; NSData * data = [NSKeyedArchiver archiveddatawithrootobject:rootviewcontroller.bugs]; [data writetofile:bugspath atomically:yes];

150 Disadvantages and Alternatives Bugs saved in one massive file Load all bugs up-front Saves images along with the data Only saves on exit Alternative: one file per bug Alternative: load on demand Alternative: save images as separate files Alternative: save periodically, or on changes

151 Synchronizing and Sharing Data - Can use File Sharing to allow users to easily transfer files with itunes - If you get that working, easy to add sharing too - ios5: icloud - Or sync with your own web service

152 Lab Time!

153 Hello, ipad!

154 What We ll Cover - Compiling for ipad - Using UISplitViewController - Using UIPopoverController - Writing conditional code

155 Base SDK vs. Deployment Target - Base SDK: SDK you re compiling with (latest) - Deployment target: minimum OS version code compatible with

156 ios Users Tend to Upgrade /08/ios-versions-in-thewild/ source: apprupt.com

157 Building for ipad in Xcode - Targeted Device Family (in Project Settings) - Main nib file base name (in Info.plist)

158 The Biggest Difference Between Developing for ipad vs iphone

159 The Biggest Difference Between Developing for ipad vs iphone

160 The Biggest Difference Between Developing for ipad vs iphone

161 A bigger size leads to different UI paradigms...

162 Apple provides new UI elements to assist you... - Bigger view controllers - More composing - UISplitViewController - UIPopoverController

163 Demo: Bigger View Controllers

164 Demo: Bigger View Controllers // Modify tableview:didselectrowatindexpath if (_detailviewcontroller == nil) { if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) { self.detailviewcontroller = [[[DetailViewController alloc] initwithnibname:@"detailviewcontroller-ipad" bundle:nil] autorelease]; } else { self.detailviewcontroller = [[[DetailViewController alloc] initwithnibname:nil bundle:nil] autorelease]; } }

165 Demo: UISplitViewController - Refactor AppDelegate to have reference to RootViewController

166 Demo: UISplitViewController // (retain) IBOutlet DetailViewController * detailviewcontroller;

167 Demo: UISplitViewController - Create refresh method on DetailViewController // RootViewController.m // Inside tableview:didselectrowatindexpath ScaryBug * bug = [_bugs objectatindex:indexpath.row]; _detailviewcontroller.bug = bug; if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) { [_detailviewcontroller refresh]; } else { [self.navigationcontroller pushviewcontroller:_detailviewcontroller animated:yes]; }

168 Demo: UISplitViewController - Create toolbar, link to Outlet - Set DetailViewController as UISplitViewController s delegate // DetailViewController.h // Mark as implementing this DetailViewController : UIViewController <UIImagePickerControllerDelegate, UITextFieldDelegate, UISplitViewControllerDelegate> { // DetailViewController.m - (void)splitviewcontroller:(uisplitviewcontroller *)svc willhideviewcontroller:(uiviewcontroller *)aviewcontroller withbarbuttonitem: (UIBarButtonItem *)barbuttonitem forpopovercontroller:(uipopovercontroller *)pc { NSMutableArray * items = [NSMutableArray array]; [items addobject:barbuttonitem]; barbuttonitem.title [items addobjectsfromarray:_toolbar.items]; [_toolbar setitems:items]; } - (void)splitviewcontroller:(uisplitviewcontroller *)svc willshowviewcontroller:(uiviewcontroller *)aviewcontroller invalidatingbarbuttonitem:(uibarbuttonitem *)barbuttonitem { } NSMutableArray * items = [NSMutableArray array]; [items addobjectsfromarray:_toolbar.items]; [items removeobject:barbuttonitem]; [_toolbar setitems:items];

169 Demo: UIPopoverController // DetailViewController.h // Add UIPopoverController * _popover; // (retain) UIPopoverController * popover; // DetailViewController.m // popover = _popover; // Add in dealloc [_popover release]; // Add inside buttontapped if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) { if (_popover == nil) { self.popover = [[[UIPopoverController alloc] initwithcontentviewcontroller:picker] autorelease]; } UIButton *button = (UIButton *)sender; [_popover presentpopoverfromrect: CGRectMake(button.center.x, button.center.y, 10, 10) inview:self.view permittedarrowdirections:uipopoverarrowdirectionany animated:yes]; } else { [self presentmodalviewcontroller:picker animated:yes]; }

170 The Final Challenge!

171 Where To Go From Here? - Make apps, gain money and skillz! - More ios dev tutorials on $75 off with discount code 360idev! - Drop me a note anytime!

172 Epic Loot Time!