iPhone and iPad Apps for Absolute Beginners

328 Pages·2010·17.54 MB·English

by  Dr. Rory Lewis (auth.)

iPhone and iPad Apps
for Absolute Beginners

■ ■ ■
Dr. Rory Lewis

i
iPhone and iPad Apps for Absolute Beginners
Copyright © 2010 by Dr. Rory Lewis
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ISBN-13 (pbk): 978-1-4302-2700-7
ISBN-13 (electronic): 978-1-4302-2701-4
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ii
To Adrian and Eunice Lewis: Love you, Granny, and I miss you so much, Pops.
—Dr. Rory Lewis

iii
Contents at a Glance
■Contents at a Glance.......................................................................................iv
■Contents..........................................................................................................v
■Foreword: About the Author...........................................................................ix
■About the Contributing Authors.....................................................................xii(cid:2)
■About the Technical Reviewer......................................................................xiii
■Acknowledgments.........................................................................................xiv
■Preface...........................................................................................................xv
■Chapter 1: Before We Get Started....................................................................1
■Chapter 2: Blast-Off!......................................................................................17
■Chapter 3: What’s Next?................................................................................53
■Chapter 4: An Introduction to the Code.........................................................71
■Chapter 5: Buttons & Labels with Multiple Graphics.....................................93
■Chapter 6: Switch View with Multiple Graphics..........................................125
■Chapter 7: Dragging, Rotating, and Scaling................................................209
■Chapter 8: Table Views, Navigation, and Arrays.........................................235
■Chapter 9: MapKit........................................................................................261
■Index............................................................................................................313
iv
Contents
■Contents at a Glance.......................................................................................iv(cid:2)
■Contents..........................................................................................................v(cid:2)
■Foreword: About the Author...........................................................................ix
■About the Contributing Authors.....................................................................xii(cid:2)
■About the Technical Reviewer......................................................................xiii(cid:2)
■Acknowledgments.........................................................................................xiv
■Preface...........................................................................................................xv(cid:2)

■Chapter 1: Before We Get Started....................................................................1
Necessities and Accessories..................................................................................................................................1
What I Won’t Teach You..........................................................................................................................................6
Computer Science: A Broad and Diverse Landscape.........................................................................................6
What You Will Learn................................................................................................................................................9
How Does This All Work?......................................................................................................................................10
Our Road Map: Using Xcode and Interface Builder..........................................................................................12
■Chapter 2: Blast-Off!......................................................................................17
helloWorld_002 – a Navigation-based Application...............................................................................................38
helloWorld_003 – Modifying a Navigation-based App..........................................................................................48
■Chapter 3: What’s Next?................................................................................53
§I: THE ROAD AHEAD.............................................................................................................................................54
Introducing Chapter 4—An Introduction to the Code......................................................................................54
Introducing Chapter 5—Buttons & Labels with Multiple Graphics..................................................................55
Introducing Chapter 6—Switch View with Multiple Graphics..........................................................................56
Introducing Chapter 7—Dragging, Rotating, and Scaling...............................................................................58
Introducing Chapter 8—Table Views, Navigation, and Arrays.........................................................................59
Introducing Chapter 9—MapKit.......................................................................................................................60
§II: THE iPHONE AND THE iPAD.............................................................................................................................60
§III: A LOOK UNDER THE HOOD..............................................................................................................................66
(cid:2)
You’ve Said “Hello!” … but now, INDIO!.........................................................................................................67
v
■ CONTENTS
■Chapter 4: An Introduction to the Code.........................................................71
004_helloWorld: Buttons with Graphics................................................................................................................72
Digging the Code...................................................................................................................................................89
Nibs, Zibs, and Xibs.........................................................................................................................................89
Methods...........................................................................................................................................................90
■Chapter 5: Buttons & Labels with Multiple Graphics.....................................93
helloWorld_005: a View-Based Application..........................................................................................................93
Preliminaries....................................................................................................................................................94
Xcode – Beginning a New Project....................................................................................................................97
Understanding IBOutlets..................................................................................................................................99
Pointers..........................................................................................................................................................101
Properties: Management & Control................................................................................................................103
Adding IBActions............................................................................................................................................105
Coding the Implementation File.....................................................................................................................106
Providing for Synthesis..................................................................................................................................108
Interface Builder: Making the Connections....................................................................................................110
Final Step: File’s Owner & uiImageView........................................................................................................118
Digging the Code.................................................................................................................................................122
IBOutlets and IBActions.................................................................................................................................122
More About Pointers......................................................................................................................................123
In the Chapter Ahead..........................................................................................................................................124
■Chapter 6: Switch View with Multiple Graphics..........................................125
einSwitch_001—a Window-Based Application..................................................................................................128
Preliminaries..................................................................................................................................................128
Name your Project “einSwitch01”.................................................................................................................133
Create the 1st UIViewController Subclass.....................................................................................................137
Create the Ein1Controller...............................................................................................................................138
Check Header and Implementation Files.......................................................................................................139
Create the Ein2Controller...............................................................................................................................139
Make Sure Images Are Embedded.................................................................................................................140
Save Einstein2View.xib..................................................................................................................................141
Drag the Images into Xcode...........................................................................................................................142
Assign your Icon in the “plist”.......................................................................................................................143
Code the AppViewDelegate............................................................................................................................144
Working SwitchView......................................................................................................................................146
SwitchViewController and AppDelegate........................................................................................................148
SwitchViewController Header File.................................................................................................................152
Ready for Lazy Load—Implementation File...................................................................................................155
A Note about Comments and Lazy Loads......................................................................................................156
Copy Contents of SwitchViewController.txt...................................................................................................158
A Note about Apple’s Boilerplate Implementation File...................................................................................159
Working on the .xib Files...............................................................................................................................161
Select the File’s Owner..................................................................................................................................163
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■ CONTENTS
Drag a View onto the Screen.........................................................................................................................163
Start Working on the Einstein#View.xib Files................................................................................................167
Repeat Process for Second Image.................................................................................................................171
einSwitch_002—a Tab-Bar Application.............................................................................................................176
einSwitch_003—a Window-Based Application..................................................................................................191
Digging … Your Brain.........................................................................................................................................207
■Chapter 7: Dragging, Rotating, and Scaling................................................209
DragRotateAndScale—a View-Based Application..............................................................................................210
Preliminaries..................................................................................................................................................211
Starting the DragRotateAndScale App...........................................................................................................211
Creating a Custom UIImageView Subclass....................................................................................................213
Overriding – initWithImage in TransformView.m...........................................................................................215
Creating Touch-Handling Stubs.....................................................................................................................216
Translating in touchesMoved.........................................................................................................................218
Making Use of TransformView.......................................................................................................................220
Creating a TransformView.............................................................................................................................220
Preparing TransformView for Rotation and Scaling.......................................................................................225
Helper Methods..............................................................................................................................................226
Adding to “-touchesBegan”...........................................................................................................................227
Modifying -touchesMoved.............................................................................................................................229
Digging the Code.................................................................................................................................................232
■Chapter 8: Table Views, Navigation, and Arrays.........................................235
How Shall We Proceed?......................................................................................................................................238
Table Views and Navigation Stacks....................................................................................................................238
Food: Following the App Store Model.................................................................................................................239
Starting the Food App....................................................................................................................................239
Adding the Category Names Array in RootViewController.h..........................................................................241
Creating the Categories Array in -viewDidLoad............................................................................................242
Setting Up Table View Data Source Methods................................................................................................243
Table View Delegation...................................................................................................................................244
Setting up FoodTableViewController..............................................................................................................245
Creating the Convenience Constructor for the FoodTableViewController......................................................248
Data Source and Delegation for the FoodTableViewController......................................................................249
Creating the FoodViewController Class..........................................................................................................250
The FoodViewController Header File..............................................................................................................251
The FoodViewController Convenience Constructor........................................................................................252
Setting Up FoodViewController, -viewDidLoad, and the (.xib).......................................................................252
Icon File.........................................................................................................................................................254
Testing the App..............................................................................................................................................255
Digging the Code.................................................................................................................................................257
Memory Management....................................................................................................................................257
Reuse Identifiers............................................................................................................................................259
■Chapter 9: MapKit........................................................................................261
vii
■ CONTENTS
A Little about Frameworks..................................................................................................................................262
Important Things to Know...................................................................................................................................263
Preinstalled MapKit Apps....................................................................................................................................263
Find Locations................................................................................................................................................264
Get Directions................................................................................................................................................265
See Which Way You’re Facing.......................................................................................................................266
See Traffic......................................................................................................................................................267
Search for a Location.....................................................................................................................................268
Cool and Popular MapKit Apps to Inspire You.....................................................................................................270
MapKit_01: A View-Based Application................................................................................................................271
Possible Prepping for the App........................................................................................................................271
Preliminaries.......................................................................................................................................................273
A New View-Based Template..............................................................................................................................273
Adding the Annotation File.............................................................................................................................274
It’s Already Working!......................................................................................................................................275
Check It Out—the iPad Simulator..................................................................................................................276
Make It Look a Little Bit Better......................................................................................................................277
Dealing with the Implementation...................................................................................................................278
Coding the myPos.h File................................................................................................................................284
The myPos.m File...........................................................................................................................................285
The AppDelegate Files...................................................................................................................................286
Connect MapView with MKMapView.............................................................................................................287
Digging My Students’ MapKit Code....................................................................................................................290
Parsing to MapKit from the Internet...............................................................................................................290
MapKit Parsing...............................................................................................................................................293
Three MapKit Final Projects: CS-201 iPhone Apps, Objective-C................................................................295
(cid:2)
Zoom Out … Seeing the Big Picture...................................................................................................................310
■Index............................................................................................................313
viii
Foreword: About the Author
"Rory and I met in L.A. in 1983. He reminds me of one of my favorite film
characters, Buckaroo Banzai—always going in six directions at once. If you stop
him and ask what he's doing, he'll answer comprehensively and with amazing
detail. Disciplined, colorful, and friendly, he has the uncanny ability to explain
the highly abstract in simple, organic terms. He always accomplishes what he
sets out to do, and he'll help you do the same.
Why you’ll relate to Dr. Lewis
While attending Syracuse University as a computer-engineering student, Rory scrambled to pass his
classes and make money to support his wife and two young daughters. In 1990, he landed a choice on-
campus job as a proctor in the computer labs in the LC Smith College of Engineering. Even though he
was struggling with subjects in the Electrical Engineering program, he was always there at the Help
Desk. It was a daunting experience for Rory because his job was only to help his fellow students with
computer lab equipment questions, but he invariably found his classmates asking deeper and harder
questions: “Dude, did you understand the calculus assignment? Can you help me?!”
These students assumed that, because Rory was the proctor, he
knew the answers. Afraid and full of self-doubt, he sought a way
to help them without revealing his inadequacies. Rory learned
to start with: “Let’s go back to the basics. Remember that last
week the professor presented us with an equation…?” By going
back to the fundamentals, restating and rebranding them, Rory
began to develop a technique that would, more often than not,
lead to working solutions. By the time his senior year rolled
around, there was often a line of students waiting at the Help
Desk on the nights Rory worked.
Fast-Forward 17 Years
Picture a long-haired, wacky professor walking through the campus of the University of Colorado
at Colorado Springs, dressed in a stunning contrast of old-school and drop-out. As he walks into
the Engineering Building, he is greeted by students and faculty who smile and say hearty hellos,
all the while probably shaking their heads at his tweed jacket, Grateful Dead t-shirt, khaki pants,
and flip flops. As he walks down the hall of the Computer Science Department, there’s a line of
students standing outside his office. Reminiscent of the line of students that waited for him at the
Help Desk in those early years as a proctor in the computer lab, they turn and greet him, “Good
morning, Dr. Lewis!” Many of these students at UC-Colorado Springs are not even in his class, but
they know that Dr. Lewis will see them and help them anyway.
ix
■ FOREWORD: ABOUT THE AUTHOR
Past—Present—Future
Dr. Lewis holds three academic degrees. He earned a Bachelor of Science in Computer
Engineering from Syracuse University. Syracuse’s LC Smith College of Engineering is one of the
country’s top schools. It is there that Intel, AMD, and Microsoft send their top employees to study
for their PhDs.
Upon completing his BS (with emphasis on the mathematics of electronic circuitry in
microprocessors), he went across the quad to the Syracuse University School of Law. During his
first summer at law school, Fulbright & Jaworski, the nation’s most prolific law firm, recruited
Rory to work in its Austin office, where some of the attorneys specialize in high-tech intellectual-
property patent litigation. As part of his clerking experience, Lewis worked on the infamous AMD
v. Intel case; he helped assess the algorithms of the mathematics of microprocessor electrical
circuitry for the senior partners.
During his second summer in law school, Skjerven, Morrill, MacPherson, Franklin, & Friel—the
other firm sharing the work on the AMD v. Intel case—recruited Rory to work with them at their
Silicon Valley branches (San Jose and San Francisco). After immersing himself in law for several
years and receiving his JD at Syracuse, Lewis realized his passion was for the mathematics of
computers, not the legal ramifications of hardware and software. He preferred a learning and
creative environment rather than the fighting and arguing intrinsic in law.
After three years away from academia, Rory Lewis moved south to pursue his PhD in Computer
Science at the University of North Carolina at Charlotte. There, he studied under Dr. Zbigniew W.
Ras, known worldwide for his innovations in data mining algorithms and methods, distributed
data mining, ontologies, and multimedia databases. While studying for his PhD, Lewis taught
computer science courses to computer engineering undergraduates, as well as e-commerce and
programming courses to MBA students.
Upon receiving his PhD in Computer Science, Rory accepted a tenure-track position in Computer
Science at the University of Colorado at Colorado Springs, where his research is in the
computational mathematics of neurosciences. Most recently, he co-wrote a grant proposal on the
mathematical analysis of the genesis of epilepsy with respect to the hypothalamus. However,
with the advent of Apple’s revolutionary iPhone and its uniquely flexible platform—and market—
for mini-applications, games, and personal computing tools, he grew excited and began
experimenting and programming for his own pleasure. Once his own fluency was established,
Lewis figured he could teach a class on iPhone apps that would include non-engineers. With his
insider knowledge as an iPhone beta tester, he began to integrate the parameters of the proposed
iPad platform into his lesson plans—even before the official release in April 2010.
The class was a resounding success and the feedback was overwhelmingly positive, from students
and colleagues alike. When approached about the prospect of converting his course into a book
to be published by Apress, Dr. Lewis jumped at the opportunity. He happily accepted an offer to
convert his course outlines, class notes, and videos into the book you are now holding in your
hands.
Why Write This Book?
The reasons Dr. Lewis wrote this book are the same reasons he originally decided to create a class
for both engineering and non-engineering majors: the challenge and the fun! According to Lewis,
the iPhone and iPad are “...some of the coolest, most powerful, and most technologically advanced
tools ever made—period!”
He is fascinated by the fact that, just under the appealing touch screen of high-resolution images
and fun little icons, the iPhone and iPad are programmed in Objective-C, an incredibly difficult
and advanced language. More and more, Lewis was approached by students and colleagues who
wanted to program apps for the iPhone and would ask his opinion on their ideas. It seemed that,
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