Page 1. GUI Programming. Lecture 13: iphone Basics. iphone. iphone

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1 GUI Programming Lecture 13: iphone Basics Until now, we have only seen code for standard GUIs for standard WIMP interfaces. Today we ll look at some code for programming mobile devices. on the surface, the code looks VERY different deep down, though, we ll see many of the same concepts at work CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 1 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 2 iphone In 4Q 2010, the Apple iphone had a worldwide market share of only 4% but accounted for 50% of the industry s profits!! iphone iphone apps, via the App Store, dominate the landscape for mobile apps 82% share in ,000 total apps 23,000 new developers in the last 6 months Other platforms, especially Android, are gaining on the iphone. But we ll focus on #1 today. Caveat: I m new to iphone development, so take all this with a grain of salt. CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 3 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 4 Page 1

2 iphone Development Language: Devices: iphone + ipad IDE: Xcode, Interface Builder, ios simulator only available on the Mac It s free to develop with Xcode using only the ios simulator. To install an app on a real device, however, you ll need to part of the Apple developer program. An object-oriented extension to C in fact, a strict superset of C: any C program can be compiled as Based on message passing the program doesn t call a method ; it sends a message C-style pointers are everywhere Java also uses pointers everywhere, but you never see them here they re exposed and used heavily CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 5 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 6 code examples derived from wikipedia Interface defined a *.h (header) classname : superclassname { // instance variables + (returntype) classmethod2; + (returntype) classmethod3 : (param1type) param1; - (returntype) instancemethod1 : (param1type) param1 andother: (param2type) param2; - (returntype) instancemethod2withparameter: (param1type) param1 Implementation defined in *.m classname + (returntype) classmethod { // implementation - (returntype) instancemethod { // CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 7 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 8 Page 2

3 Example: Book : NSObject { NSString *title; NSString *author; NSString *year; NSString (nonatomic, retain) NSString (nonatomic, retain) NSString (nonatomic, retain) NSString (nonatomic, retain) NSString Top-level generic object String object defines basic methods Example: title, author, year, publisher; - (void) dealloc { [title release]; [author release]; [year release]; [publisher release]; [super Implements basic methods Huh?? CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 9 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 10 Memory allocation & pointers Java allocates memory with: new Object() and frees this memory whenever you re done: Garbage Collection you never need to worry about memory makes you worry about this. We ll only worry a little in this lecture. If you do this for a living, you ll worry a lot more. Pointers & allocation Book *book = [[Book alloc] init]; Deallocation of memory the system maintains an internal counter that tracks references (pointers) to objects [object retain] // increments the counter by 1 [object release] // decrements the counter by 1 // if the counter hits 0, the object is deallocated CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 11 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 12 Page 3

4 A First App As an exercise, let s implement an app that provides (more or less) the same functionality as your first Swing assignment. BookLogger: maintain a list of books add new books edit existing books delete books Then we ll extend this a little to take advantage of the iphone s unique components. Tools Xcode IDE: editor, compiler, debugger Interface Builder a GUI-style way to specify interfaces ios Simulator runs your app in simulation no iphone needed CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 13 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 14 Paradigm: MVC Xcode: Create the Project Model, View, Controller (MVC) is critical model, as you know, is the core data for the components view can be specified in Interface Builder controllers implemented in Xcode and can be associated with views and models either through Interface Builder, or through raw code CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 15 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 16 Page 4

5 Xcode: Create the Project IB: Edit MainWindow.xib CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 17 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 18 Interface Builder Drag-and-drop (a lot of) components Xcode Specify classes that implement the view/ controllers #import books; - (void)viewdidload { [super viewdidload]; self.title - (void)viewwillappear:(bool)animated { [self.tableview reloaddata]; CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 19 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 20 Page 5

6 IB ß à Xcode Can associate IB elements with their respective implementations associate element and class IB ß à Xcode Can associate IB elements with their respective implementations associate element and variable CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 21 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 22 RootViewController.h RootViewController.m CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 23 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 24 Page 6

7 RootViewController.m RootViewController.m CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 25 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 26 DetailViewController.xib DetailViewController.h CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 27 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 28 Page 7

8 DetailViewController.m AddViewController.h CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 29 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 30 AddViewController.m An Augmented Version Up to here, we ve just implemented a skeletal version of Assignment 1. Now let s take advantage of something more unique to the iphone namely, easy inclusion of its mobile web browser (UIWebView) CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 31 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 32 Page 8

9 BuyViewController.h BuyViewController.m CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 33 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 34 An Augmented Version The easy-buy-it feature Deployment Submitting to the App Store Apple controls what s on the App Store, and therefore what s on (most) people s iphones Reasons for rejecting apps (from 10base-t.com) Vibration. It is not permitted to use continuous vibration in your apps short bursts as warnings is all that is allowed. Improper handling of editing in tableview cells. If you enable table cell editing, you ll have to manually specify which cells should respond to editing controls and which should not. CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 35 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 36 Page 9

10 Deployment Reasons for rejecting apps (cont.) Icons. Make sure the 57 pixel icon is identical to the 512 pixel version. Also, use a different icon if you are creating lite and pro versions of your app (i.e., free and paid). Copying existing functionality. This one is much more subtle and insidious, and has probably affected the great percentage of developers. Apple is casting a wide net when looking for duplicated functionality. Mini web browsers, or apps that essentially show web pages, seem particularly vulnerable, even if they add new and/or useful functionality. Stay away from clients as well. Deployment Reasons for rejecting apps (cont.) Using appropriate keyboard type. If your app asks for a phone number or other numeral-only input and you present a keyboard that also includes the possibility of entering alpha-numeric input. Version numbers. Must be Using Apple s graphics in your own apps. We ve heard of projects being rejected for using the Bonjour logo, as well as Apple s network icon (the little picture of the globe with all the glowing lines), and others. Even if you use Apple s button images you may tempt fate if you use them in any way that is at odds with how Apple uses them. CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 37 CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 38 Deployment Reasons for rejecting apps (cont.) Network reachability. If your app uses a network connection, it is YOUR responsibility to tell the user if and when their device loses its network connection. Offensive language from your users. If your app has an interactive component that lets users post text, or if your app pulls user-generated content from the internet, it is YOUR responsibility to censor the language. CS 338: Graphical User Interfaces. Dario Salvucci, Drexel University. 39 Page 10