standford cs 193p: 07-viewcontrollers

8/14/2019 Standford CS 193P: 07-ViewControllers

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CS193P - Lecture 7

iPhone Application Development

Designing iPhone ApplicationsView Controllers


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Announcements

Grades for Assignment 1 are up on Coursework! A "means that you satisfied the requirements.

Assignment 3 due tomorrow (Wednesday, October 15)

iStanford commercial...


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iStanford Commercial


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Todays Topics

Questions on Assignment 3?

Designing iPhone Applications

View Controllers

Presence Intro


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Two Flavors of Mail


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Organizing Content

Focus on data

One thing at a time

Screenfuls of content


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Patterns for Organizing Content

Navigation Bar Tab Bar


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Navigation Bar

Hierarchy of content

Drill down into greater detail


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Tab Bar

Self-contained modes


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A Screenful of Content

Slice of your application

Views, data, logic


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Parts of a Screenful


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View Controllers


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UIViewController

Basic building block

Manages a screenful of content

Subclass to add your application logic

View Controller


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UIViewController





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UIViewController





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Your and Our View Controllers

Create your own UIViewController subclass for each screenful

Plug them together using existing composite view controllers

View Controller

View Controller

View Controller

NavigationController


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Your and Our View Controllers

Create your own UIViewController subclass for each screenful

Plug them together using existing composite view controllers

View Controller

View Controller

View Controller

Tab BarController


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Your View Controller Subclass

#import

@interface MyViewController : UIViewController {

// A view controller will usually

// manage views and data

NSMutableArray *myData;

UIView *myView;

}

// Expose some of its contents to clients

@property (readonly) NSArray *myData;

// And respond to actions

- (void)doSomeAction:(id)sender;


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The View in View Controller

UIViewController superclass has a view property! @property (retain) UIView *view;

Loads lazily! As needed, on demand

! Can be purged on demand as well (low memory)

Sizing and positioning the view?! Depends on where its being used

! Dont make assumptions, be flexible


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Creating Your View in Code

Override -loadView! Never call this directly

Create your views

Set the view property

Create view controller with -init

// Subclass of UIViewController

- (void)loadView

{

}

MyView *myView = [[MyView alloc] initWithFrame:frame];

[myView release];

self.view = myView; // The view controller now owns the view


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Creating Your View with Interface Builder

Lay out a view in Interface Builder

View controller is files owner

Hook up view outlet

Create view controllerwith -initWithNibName:bundle:


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Demo:

View Controllers with IB


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View Controller Lifecycle- (id)initWithNibName:(NSString *)nibName

bundle:(NSBundle *)bundle{

if (self == [super init...]) {

// Perform initial setup, nothing view-related

myData = [[NSMutableArray alloc] init];

self.title = @Foo;

}return self;

}

- (void)viewDidLoad

{ // Your view has been loaded

// Customize it here if needed

view.someWeirdProperty = YES;

}


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View Controller Lifecycle- (void)viewWillAppear:(BOOL)animated

{[super viewWillAppear:animated];

// Your view is about to move onscreen

[self beginLoadingDataFromTheWeb];

[self startShowingLoadingProgress];

}

- (void)viewWillDisappear:(BOOL)animated

{

[super viewWillDisappear:animated];

// Your view is about to move offscreen

[self saveDataToDisk];

}


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Loading & Saving Data

Lots of options out there, depends on what you need! NSUserDefaults

! Property lists

! SQLite

! Web services

! Something else?


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Demo:

Loading & Saving Data


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More View Controller Hooks

Automatically rotating user interface! - (BOOL)shouldAutorotateToInterfaceOrientation:

(UIInterfaceOrientation)interfaceOrientation;

Responding to low memory situations! - (void)didReceiveMemoryWarning;


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Demo:

Rotating Your Interface


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Autoresizing Your Views

view.autoresizingMask = UIViewAutoresizingFlexibleWidth |

UIViewAutoresizingFlexibleHeight;

view.autoresizingMask = UIViewAutoresizingFlexibleWidth |

UIViewAutoresizingFlexibleTopMargin;


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Presence


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Presence

Building an iPhone application for viewing online statusupdates, also known as presence! What are you doing right now?

Our assignments will be using Twitter! Could extend to Facebook updates, IM status, RSS feeds...

Four part assignment, each one builds on the previous


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Presence - Part 1

Due next Wednesday 10/22

Goals! Create your own view controller subclasses

! Present a hierarchy using UINavigationController (next lecture)


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Demo:

Presence


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Questions?

standford cs 193p: 07-viewcontrollers

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