Building on the phenomenal success of its predecessor, iOS 5 includes over 200 new user features as well as an updated SDK containing over 1,500 new APIs. iOS 5 looks set to reinforce the iPhone's dominance in the smartphone market.
iOS 5 Essentials will help you learn how to build simple, yet powerful iOS 5 applications, incorporating iCloud Storage, Twitter, Core Image and Newsstand integration.
You will start by learning about what's new in iOS 5. You'll look at the iCloud Storage APIs, Automatic Reference Counting, Twitter, and AirPlay integration, how to use the various Core Image filters using the Cocoa framework, and the new features of the iOS 5 SDK. After this, you'll jump straight in and create applications using Xcode and Interface Builder using the new storyboard layout. We then finish up by learning how to make your applications run smoothly using the Xcode instruments.
In this book, I have tried my best to keep the code simple and easy-to-understand. I have provided step-by-step instructions with loads of screenshots at each step to make it easier to follow. You will soon be mastering the different aspects of iOS 5 programming, as well as mastering the technology and skills needed to create some stunning applications. Feel free to contact me at <[email protected]> for any queries, or just want to say 'hello'. Any suggestions for improving this book will be highly regarded.
Chapter 1, What's New in iOS5, introduces the developer to the Xcode developer set of tools, the new features of iOS 5, as well as an introduction into Newsstand and the MessageUI framework.
Chapter 2, Using iCloud and the Storage APIs, introduces you to the benefits of using iCloud, and how to incorporate iCloud functionality into your applications to store and retrieve files, and its data through the use of the storage APIs. This chapter will also give you some insight into how to go about handling file-version conflicts when multiple copies of the same file are being updated on more than one iOS device.
Chapter 3, Debugging with OpenGL ES, focuses on the differences between vertex shaders and fragment shaders, and their relationship with one another. We will become familiar with the OpenGL ES 2.0 Programmable pipeline, and look into the new debugging features of OpenGL ES that enables us to track down issues specific to OpenGL ES, right within the Xcode IDE. We will learn more about the OpenGL ES frame capture tool and its ability to stop execution of a program, that will enable the developer to grab the current frame contents that are being rendered on the iOS device, so that program issues can be tracked down and corrected, by taking a closer look at the program state information of objects, by scrolling through the debug navigator stack trace with the ability to see all of the textures and shaders that are currently being used by the application.
Chapter 4, Using Storyboards, gains an understanding of what Storyboards are and how we can apply the various transitions between views. We will take a look into how we are able to create and configure scenes and storyboard files, to present these programmatically. We will also look at how to go about building and integrating Twitter capabilities into our application to tweet photos and standard messages.
Chapter 5, Using AirPlay and Core Image, focuses on learning about the AirPlay and Core Image frameworks, and how we go about using and implementing these into our applications. This chapter also explains the different image filter effects, how to adjust the brightness of an image, as well as how to go about producing a water ripple effect. It also covers how to incorporate AirPlay functionality into your application, so that you can have your application displayed out to an external device, such as an Apple TV.
Chapter 6, Xcode Tools - Improvements, focuses on learning about the improvements that have been made to the Xcode development tools. We will take a look at Automatic Reference Counting (ARC), which is the latest addition that has been made to the LLVM compiler, and how this can help improve application performance, by minimizing issues with our applications. It also covers improvements that have been made to Interface Builder, the iOS Location simulator, and the set of debugging tools for OpenGL ES.
Chapter 7, Making your Applications Run Smoothly Using Instruments, focuses on how we can effectively use Instruments within our applications to track down memory leaks and bottlenecks within our applications that could potentially cause our application to crash on the user's iOS device. We will take a look into each of the different types of built-in instruments that come as part of the Instruments application, learn how we can use the System Trace instrument to monitor system calls, and track down performance issues within an application.
This book assumes that you have an Intel-based Macintosh running Snow Leopard (Mac OS X 10.6.2, or later). You can use Leopard, but I would highly recommend upgrading to Snow Leopard or Lion, as there are many new features in Xcode that are available only to these two operating systems.
We will be using Xcode 4.2.1, which is the integrated development environment used for creating applications for iOS development. You can download the latest version of Xcode at the following link: http://developer.apple.com/xcode/.
If you ever wanted to learn about the latest features of iOS 5 and learn how to incorporate Twitter, iCloud and Core Image framework effects functionality into your applications, then this book is for you. You should have a good knowledge of programming experience with Objective-C, and have used Xcode 4. iOS programming experience is not required.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text are shown as follows: "Launch Xcode from the /Developer/Applications folder."
A block of code is set as follows:
#import <UIKit/UIKit.h>
#import <MessageUI/MessageUI.h>
@interface MyEmailAppViewController: UIViewController<MFMailComposeViewControllerDelegate> {}
@endWhen we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
<plist version="1.0">
<dict>
<key>application-identifier</key>
<string>AXEUZ3F6VR.com.geniesoftstudios</string>
<key>com.apple.developer.ubiquity-container-identifiers</key>
<array>
<string>TEAMID.com.yourcompany.iCloudExample</string>
</array>
<key>com.apple.developer.ubiquity-kvstore-identifier</key>
<string>TEAMID.com.yourcompany.iCloudExample</string>
<key>get-task-allow</key>
<true/>
</dict>
</plist>New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "When Xcode is launched, you should see the Welcome to Xcode screen."
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