iPhone Advanced Projects

395 Pages·2009·4.74 MB·English

by  David Mark

Development Tales of
iPhone App Masters
iPhone
Advanced Projects
| | |
Joachim Bondo Dylan Bruzenak Steve Finkelstein Owen Goss
| | |
Tom Harrington Peter Honeder Florian Pflug Ray Kiddy
| | |
Noel Llopis Joe Pezzillo Jonathan Saggau Ben Britten Smith
Preface by Glenn Cole
BOOKS FOR PROFESSIONALS BY PROFESSIONALS®

T
he Apress series of iPhone Projects books features experienced app develop-
ers presenting their own work in their own words. You get firsthand accounts
of what it takes to design, implement, and launch some of the finest applications
available from Apple’s iTunes App Store.
iPhone Advanced Projects, the third book in this series, tackles some advanced as-
pects of iPhone development. The first generation of iPhone applications has hit the
App Store, and now it’s time to optimize performance, streamline the user interfaces,
and make every successful iPhone app just that much more sophisticated.
Your guides for this exploration of the next level of iPhone development include the
following:
•
Ben Britten Smith, discussing particle systems using OpenGLES
•
Joachim Bondo, demonstrating his implementation of correspondence
gaming in the most recent version of his chess application, Deep Green
•
Tom Harrington, implementing streaming audio with Core Audio, one of
many iPhone OS 3 APIs
•
Owen Goss, debugging those pesky errors in your iPhone code with an eye
toward achieving professional-strength results
•
Dylan Bruzenak, building a data-driven application with SQLite
•
Ray Kiddy, illustrating the full application development life cycle with
Core Data
•
Steve Finkelstein, marrying an offline e-mail client to Core Data

•
Peter Honeder and Florian Pflug, tackling the challenges of networked
applications in WiFi environments
•
Jonathan Saggau, improving interface responsiveness with some of his
personal tips and tricks, including “blocks” and other esoteric techniques
•
Joe Pezzillo, pushing the frontiers of iPhone OS 3’s new Apple Push
Notification Service (APNS) that makes the cloud the limit for iPhone apps
•
Noel Llopis, taking mere programmers on a really advanced developmental
adventure into the world of environment mapping with OpenGLES
S
E
L It’s a full banquet of treats, so dig in where the morsels look most tempting. There’s
T
TI plenty here for every palate. Apress also offers a nourishing first course with its
D
E best-selling Beginning iPhone 3 Development: Exploring the iPhone SDK. And we’re
T
A always on the lookout for what’s new and even tastier, so feel free to share your
L
E
R most n our ishing app s with us. We’d lov e to be ab le to add them to th e next volu me
of iPhone Projects.

This book is for all iPhone application d eve lopers with a ny level o f e xperien ce or com -
ing from any development platform who wants to see how an advanced app is made.

Take what you learn in this book and use it to create the next great iPhone app!

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iPhone Advanced Projects
■■■
Dave Mark, Series Editor
Joachim Bondo
Ray Kiddy
Dylan Bruzenak
Noel Llopis
Steve Finkelstein
Joe Pezzillo
Owen Goss
Florian Pflug
Tom Harrington
Jonathan Saggau
Peter Honeder
Ben Britten Smith
iPhone Advanced Projects
Copyright © 2009 by Dave Mark, Joachim Bondo, Dylan Bruzenak, Steve Finkelstein, Owen Goss, Tom Harrington,
Peter Honeder, Ray Kiddy, Noel Llopis, Joe Pezzillo, Florian Pflug, Jonathan Saggau, Ben Britten Smith
All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic
or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the
prior written permission of the copyright owner and the publisher.
ISBN-13 (pbk): 978-1-4302-2403-7
ISBN-13 (electronic): 978-1-4302-2404-4
Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1
Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a
trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with
no intention of infringement of the trademark.
Lead Editor: Clay Andres
Technical Reviewer: Glenn Cole
Developmental Editor: Douglas Pundick
Editorial Board: Clay Andres, Steve Anglin, Mark Beckner, Ewan Buckingham, Tony Campbell, Gary Cornell,
Jonathan Gennick, Michelle Lowman, Matthew Moodie, Jeffrey Pepper, Frank Pohlmann, Ben Renow-
Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh
Coordinating Editor: Kelly Moritz
Copy Editor: Kim Wimpsett
Compositor: MacPS, LLC
Indexer: Julie Grady
Artist: April Milne
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The information in this book is distributed on an “as is” basis, without warranty. Although every precaution
has been taken in the preparation of this work, neither the author(s) nor Apress shall have any liability to any
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2ii
To my lovely wife, Leonie.
—Ben Britten Smith
To my wife, Malena, who once again gave me the support I hadn’t earned.
—Joachim Bondo
To everyone I know and to everyone I haven’t met yet.
—Dylan Bruzenak
To all of my family and friends for their support and patience with my demanding schedule. To my loving
wife, Michelle, who sustains me and encourages me to take risks. Finally, this one is for my grandmother,
Asya; you will live forever in all our hearts.
—Steve Finkelstein
To the iPhone game developers on Twitter for sharing so much and being such a supportive community.
—Noel Llopis (@snappytouch on Twitter)
I’m so grateful to so many people I can’t possibly hope to name them all individually, so, en masse, let me
thank the blessing that is my family (especially my son), the unstoppable geniuses at Apple, the folks at
Apress who patiently awaited my writing, the incredibly supportive Mac and iPhone indie developer
community, all my clients and customers, my business partners and colleagues, and, of course, the great
ineffable spirit of the universe that makes everything possible.
Thank you!
—Joe Pezzillo
To my family, my friends, the island “La Palma,” and the one who introduced me to it.
—Florian Pflug
To Dr. Michele, who doesn’t let me call her doctor. Thanks for making me
type.
—Jonathan Saggau
iii
Contents at a Glance
■Contents at a Glance ................................................................................................................................................................ iv
■Contents .................................................................................................................................................................................... v
■Foreword ................................................................................................................................................................................. xi
■About the Technical Reviewer ................................................................................................................................................ xii
■Preface ................................................................................................................................................................................... xiii
Ben Britten Smith ........................................................................................................................................................................ 1
■Everything You Ever Wanted to Know About Particle Systems ................................................................................................ 3
Joachim Bondo .......................................................................................................................................................................... 37
■Chess on the ’Net: Correspondence Gaming with Deep Green ................................................................................................ 39
Tom Harrington .......................................................................................................................................................................... 63
■Audio Streaming: An Exploration into Core Audio .................................................................................................................. 65
Owen Goss ................................................................................................................................................................................. 99
■You Go Squish Now! Debugging on the iPhone ..................................................................................................................... 101
Dylan Bruzenak ........................................................................................................................................................................ 139
■Building Data-Driven Applications with Active Record and SQLite ...................................................................................... 141
Ray Kiddy ................................................................................................................................................................................. 181
■Core Data and Hard-Core Design .......................................................................................................................................... 183
Steve Finkelstein ..................................................................................................................................................................... 209
■Smart In-Application E-mail with Core Data and Three20 ................................................................................................... 211
Florian Pflug and Peter Honeder .............................................................................................................................................. 247
■How iTap Tackles the Challenges of Networking .................................................................................................................. 249
Jonathan Saggau ..................................................................................................................................................................... 277
■Fake It ’Til You Make It: Tips and Tricks for Improving Interface Responsiveness .............................................................. 279
Joe Pezzillo .............................................................................................................................................................................. 311
■Demystifying the Apple Push Notification Service ............................................................................................................... 313
Noel Llopis ............................................................................................................................................................................... 345
■Environment Mapping and Reflections with OpenGL ES ...................................................................................................... 347
■Index ..................................................................................................................................................................................... 365
4iv
Contents
■Contents at a Glance ............................................................................................................... iv(cid:3)
■Contents .................................................................................................................................. v(cid:3)
■Foreword ................................................................................................................................ xi(cid:3)
■About the Technical Reviewer ............................................................................................... xii
■Preface ................................................................................................................................. xiii
Ben Britten Smith ....................................................................................................................... 1(cid:3)
■CHAPTER 1: Everything You Ever Wanted to Know
About Particle Systems .................................................................................................... 3(cid:3)
Adding Life to Your Game with Particles ..................................................................................................................................................5
Basic Particle Systems and You ...............................................................................................................................................................7
Overview of the Sample Code .............................................................................................................................................................8
Basic Game Flow .................................................................................................................................................................................9
The Anatomy of a Particle System ....................................................................................................................................................10
Code! Finally! ....................................................................................................................................................................................12
Slight Tangent About Degenerates ....................................................................................................................................................15
Back to the Code ...............................................................................................................................................................................16
Random Numbers and Initial Conditions ...........................................................................................................................................19
Emitting Particles ..............................................................................................................................................................................20
Tweaking Your Particle System .............................................................................................................................................................21
May the Force Be with Your Particles ...............................................................................................................................................25
Amazing Technicolor Dream Particle .....................................................................................................................................................28
Off on a Tangent: Lerping ..................................................................................................................................................................28
Color-Changing Particles ...................................................................................................................................................................30
Summary ................................................................................................................................................................................................35
v
■ CONTENTS
Joachim Bondo.........................................................................................................................37(cid:3)
■Chapter 2: Chess on the ’Net: Correspondence
Gaming with Deep Green................................................................................................39(cid:3)
Deep Green, an Already Awesome Application......................................................................................................................................40
The Tasks at Hand..................................................................................................................................................................................42
Inviting a Friend to a Game...............................................................................................................................................................43
Accepting the Invitation....................................................................................................................................................................43
Making a Move..................................................................................................................................................................................43
Getting Notified.................................................................................................................................................................................43
The Tools of the Trade............................................................................................................................................................................44
Stop Talking, Start Coding!....................................................................................................................................................................45
Installing the Tools............................................................................................................................................................................45
Coding the Web Service....................................................................................................................................................................47
Accepting the Challenge on the Device.............................................................................................................................................54
Making a Move..................................................................................................................................................................................57
Summary................................................................................................................................................................................................61
Tom Harrington ........................................................................................................................63(cid:3)
■Chapter 3: Audio Streaming: An Exploration into Core Audio...............................................65(cid:3)
Hey, I Could Write an App to Play Music................................................................................................................................................66
MPMoviePlayerController: Hey, This Is Easy! Right?..............................................................................................................................66
Finding a Better Approach......................................................................................................................................................................68
The System-Sound Way....................................................................................................................................................................69
AVAudioPlayer: The Not-Available-in-Beta Way................................................................................................................................69
Doing It the Cowboy Way with Core Audio.............................................................................................................................................74
Getting Halfway There: Audio Queue Services..................................................................................................................................74
Getting the Rest of the Way There: Audio File Stream Services........................................................................................................81
Putting It All into an App.........................................................................................................................................................................93
One More Thing.................................................................................................................................................................................93
Launch It!...............................................................................................................................................................................................96
iPhone 3.0 and Further Work.................................................................................................................................................................96
Summary................................................................................................................................................................................................97
Owen Goss................................................................................................................................99(cid:3)
■Chapter 4: You Go Squish Now! Debugging on the iPhone..................................................101(cid:3)
Assumed Knowledge............................................................................................................................................................................102
Objective-C vs. C and C++...................................................................................................................................................................104
While You’re Writing That Code............................................................................................................................................................105
Custom Asserts...............................................................................................................................................................................105
Custom Logging..............................................................................................................................................................................107
Using #define..................................................................................................................................................................................108
Crash!...................................................................................................................................................................................................109
Getting a Crash Log from Your Testers...........................................................................................................................................109
You Have Been Saving Your dSYM Files, Right?.............................................................................................................................110
Symbolicatinga Crash Log..............................................................................................................................................................110
6vi
■ CONTENTS
Using atos.......................................................................................................................................................................................111
Reproducing Rare Crashes...................................................................................................................................................................112
Thread.............................................................................................................................................................................................112
System............................................................................................................................................................................................113
Race Conditions..............................................................................................................................................................................113
The Scientific Method of Debugging....................................................................................................................................................113
Forming a Hypothesis.....................................................................................................................................................................113
Creating a Test for Your Hypothesis................................................................................................................................................114
Proving or Disproving Your Hypothesis...........................................................................................................................................115
Increasing the Probability of the Crash...........................................................................................................................................115
So, You Have a Call Stack....................................................................................................................................................................115
Starting Code...................................................................................................................................................................................115
What Is a Memory Stomp?..............................................................................................................................................................118
Identifying a Mem Stomp................................................................................................................................................................122
Tools to Detect Memory Problems..................................................................................................................................................123
Watching Variables.........................................................................................................................................................................131
Link Map Files.................................................................................................................................................................................135
Summary..............................................................................................................................................................................................137
Dylan Bruzenak......................................................................................................................139(cid:3)
■Chapter 5: Building Data-Driven Applications with
Active Record and SQLite.............................................................................................141(cid:3)
A Short Road Off a High Cliff (How I Got Here)....................................................................................................................................141
Ready! Set! Wait, What? (Why I Decided to Write a To-Do Application)...............................................................................................142
Data-Driven Applications on the iPhone...............................................................................................................................................143
Active Record: A Simple Way of Accessing Data................................................................................................................................144
Writing a Database Wrapper Around the C API: ISDatabase................................................................................................................144
Setting Up the Example Project.......................................................................................................................................................145
Creating and Initializing the Database............................................................................................................................................148
Opening a Database Connection.....................................................................................................................................................149
Making Simple Requests.................................................................................................................................................................152
More Advanced SQL.............................................................................................................................................................................158
Preventing Duplicate Create Statements........................................................................................................................................158
Handling Parameters.......................................................................................................................................................................160
Refactoringand Cleanup.................................................................................................................................................................162
Grouping Statements into Transactions..........................................................................................................................................163
Writing a Simple Active Record Layer: ISModel...................................................................................................................................164
Maintaining the Database Connection............................................................................................................................................165
The Model Object: Grocery Item......................................................................................................................................................165
How Groceries Are Mapped.............................................................................................................................................................166
Saving.............................................................................................................................................................................................168
Updating..........................................................................................................................................................................................170
Deleting...........................................................................................................................................................................................170
Finding Grocery Items.....................................................................................................................................................................171
Putting It All Together......................................................................................................................................................................174
vii