- •Contents at a Glance
- •About the Authors
- •About the Technical Reviewer
- •Acknowledgments
- •Preface
- •What This Book Is
- •What You Need
- •Developer Options
- •What You Need to Know
- •What’s Different About Coding for iOS?
- •Only One Active Application
- •Only One Window
- •Limited Access
- •Limited Response Time
- •Limited Screen Size
- •Limited System Resources
- •No Garbage Collection, but…
- •Some New Stuff
- •A Different Approach
- •What’s in This Book
- •What’s New in This Update?
- •Are You Ready?
- •Setting Up Your Project in Xcode
- •The Xcode Workspace Window
- •The Toolbar
- •The Navigator View
- •The Jump Bar
- •The Utility Pane
- •Interface Builder
- •New Compiler and Debugger
- •A Closer Look at Our Project
- •Introducing Xcode’s Interface Builder
- •What’s in the Nib File?
- •The Library
- •Adding a Label to the View
- •Changing Attributes
- •Some iPhone Polish—Finishing Touches
- •Bring It on Home
- •The Model-View-Controller Paradigm
- •Creating Our Project
- •Looking at the View Controller
- •Understanding Outlets and Actions
- •Outlets
- •Actions
- •Cleaning Up the View Controller
- •Designing the User Interface
- •Adding the Buttons and Action Method
- •Adding the Label and Outlet
- •Writing the Action Method
- •Trying It Out
- •Looking at the Application Delegate
- •Bring It on Home
- •A Screen Full of Controls
- •Active, Static, and Passive Controls
- •Creating the Application
- •Implementing the Image View and Text Fields
- •Adding the Image View
- •Resizing the Image View
- •Setting View Attributes
- •The Mode Attribute
- •Interaction Checkboxes
- •The Alpha Value
- •Background
- •Drawing Checkboxes
- •Stretching
- •Adding the Text Fields
- •Text Field Inspector Settings
- •Setting the Attributes for the Second Text Field
- •Creating and Connecting Outlets
- •Closing the Keyboard
- •Closing the Keyboard When Done Is Tapped
- •Touching the Background to Close the Keyboard
- •Adding the Slider and Label
- •Creating and Connecting the Actions and Outlets
- •Implementing the Action Method
- •Adding Two Labeled Switches
- •Connecting and Creating Outlets and Actions
- •Implementing the Switch Actions
- •Adding the Button
- •Connecting and Creating the Button Outlets and Actions
- •Implementing the Segmented Control Action
- •Implementing the Action Sheet and Alert
- •Conforming to the Action Sheet Delegate Method
- •Showing the Action Sheet
- •Spiffing Up the Button
- •Using the viewDidLoad Method
- •Control States
- •Stretchable Images
- •Crossing the Finish Line
- •The Mechanics of Autorotation
- •Points, Pixels, and the Retina Display
- •Autorotation Approaches
- •Handling Rotation Using Autosize Attributes
- •Configuring Supported Orientations
- •Specifying Rotation Support
- •Designing an Interface with Autosize Attributes
- •Using the Size Inspector’s Autosize Attributes
- •Setting the Buttons’ Autosize Attributes
- •Restructuring a View When Rotated
- •Creating and Connecting Outlets
- •Moving the Buttons on Rotation
- •Swapping Views
- •Designing the Two Views
- •Implementing the Swap
- •Changing Outlet Collections
- •Rotating Out of Here
- •Common Types of Multiview Apps
- •The Architecture of a Multiview Application
- •The Root Controller
- •Anatomy of a Content View
- •Building View Switcher
- •Creating Our View Controller and Nib Files
- •Modifying the App Delegate
- •Modifying BIDSwitchViewController.h
- •Adding a View Controller
- •Building a View with a Toolbar
- •Writing the Root View Controller
- •Implementing the Content Views
- •Animating the Transition
- •Switching Off
- •The Pickers Application
- •Delegates and Data Sources
- •Setting Up the Tab Bar Framework
- •Creating the Files
- •Adding the Root View Controller
- •Creating TabBarController.xib
- •The Initial Test Run
- •Implementing the Date Picker
- •Implementing the Single-Component Picker
- •Declaring Outlets and Actions
- •Building the View
- •Implementing the Controller As a Data Source and Delegate
- •Implementing a Multicomponent Picker
- •Declaring Outlets and Actions
- •Building the View
- •Implementing the Controller
- •Implementing Dependent Components
- •Creating a Simple Game with a Custom Picker
- •Writing the Controller Header File
- •Building the View
- •Adding Image Resources
- •Implementing the Controller
- •The spin Method
- •The viewDidLoad Method
- •Final Details
- •Linking in the Audio Toolbox Framework
- •Final Spin
- •Table View Basics
- •Table Views and Table View Cells
- •Grouped and Plain Tables
- •Implementing a Simple Table
- •Designing the View
- •Writing the Controller
- •Adding an Image
- •Using Table View Cell Styles
- •Setting the Indent Level
- •Handling Row Selection
- •Changing the Font Size and Row Height
- •Customizing Table View Cells
- •Adding Subviews to the Table View Cell
- •Creating a UITableViewCell Subclass
- •Adding New Cells
- •Implementing the Controller’s Code
- •Loading a UITableViewCell from a Nib
- •Designing the Table View Cell in Interface Builder
- •Using the New Table View Cell
- •Grouped and Indexed Sections
- •Building the View
- •Importing the Data
- •Implementing the Controller
- •Adding an Index
- •Implementing a Search Bar
- •Rethinking the Design
- •A Deep Mutable Copy
- •Updating the Controller Header File
- •Modifying the View
- •Modifying the Controller Implementation
- •Copying Data from allNames
- •Implementing the Search
- •Changes to viewDidLoad
- •Changes to Data Source Methods
- •Adding a Table View Delegate Method
- •Adding Search Bar Delegate Methods
- •Adding a Magnifying Glass to the Index
- •Adding the Special Value to the Keys Array
- •Suppressing the Section Header
- •Telling the Table View What to Do
- •Putting It All on the Table
- •Navigation Controller Basics
- •Stacky Goodness
- •A Stack of Controllers
- •Nav, a Hierarchical Application in Six Parts
- •Meet the Subcontrollers
- •The Disclosure Button View
- •The Checklist View
- •The Rows Control View
- •The Movable Rows View
- •The Deletable Rows View
- •The Editable Detail View
- •The Nav Application’s Skeleton
- •Creating the Top-Level View Controller
- •Setting Up the Navigation Controller
- •Adding the Images to the Project
- •First Subcontroller: The Disclosure Button View
- •Creating the Detail View
- •Modifying the Disclosure Button Controller
- •Adding a Disclosure Button Controller Instance
- •Second Subcontroller: The Checklist
- •Creating the Checklist View
- •Adding a Checklist Controller Instance
- •Third Subcontroller: Controls on Table Rows
- •Creating the Row Controls View
- •Adding a Rows Control Controller Instance
- •Fourth Subcontroller: Movable Rows
- •Creating the Movable Row View
- •Adding a Move Me Controller Instance
- •Fifth Subcontroller: Deletable Rows
- •Creating the Deletable Rows View
- •Adding a Delete Me Controller Instance
- •Sixth Subcontroller: An Editable Detail Pane
- •Creating the Data Model Object
- •Creating the Detail View List Controller
- •Creating the Detail View Controller
- •Adding an Editable Detail View Controller Instance
- •But There’s One More Thing. . .
- •Breaking the Tape
- •Creating a Simple Storyboard
- •Dynamic Prototype Cells
- •Dynamic Table Content, Storyboard-Style
- •Editing Prototype Cells
- •Good Old Table View Data Source
- •Will It Load?
- •Static Cells
- •Going Static
- •So Long, Good Old Table View Data Source
- •You Say Segue, I Say Segue
- •Creating Segue Navigator
- •Filling the Blank Slate
- •First Transition
- •A Slightly More Useful Task List
- •Viewing Task Details
- •Make More Segues, Please
- •Passing a Task from the List
- •Handling Task Details
- •Passing Back Details
- •Making the List Receive the Details
- •If Only We Could End with a Smooth Transition
- •Split Views and Popovers
- •Creating a SplitView Project
- •The Storyboard Defines the Structure
- •The Code Defines the Functionality
- •The App Delegate
- •The Master View Controller
- •The Detail View Controller
- •Here Come the Presidents
- •Creating Your Own Popover
- •iPad Wrap-Up
- •Getting to Know Your Settings Bundle
- •The AppSettings Application
- •Creating the Project
- •Working with the Settings Bundle
- •Adding a Settings Bundle to Our Project
- •Setting Up the Property List
- •Adding a Text Field Setting
- •Adding an Application Icon
- •Adding a Secure Text Field Setting
- •Adding a Multivalue Field
- •Adding a Toggle Switch Setting
- •Adding the Slider Setting
- •Adding Icons to the Settings Bundle
- •Adding a Child Settings View
- •Reading Settings in Our Application
- •Retrieving User Settings
- •Creating the Main View
- •Updating the Main View Controller
- •Registering Default Values
- •Changing Defaults from Our Application
- •Keeping It Real
- •Beam Me Up, Scotty
- •Your Application’s Sandbox
- •Getting the Documents Directory
- •Getting the tmp Directory
- •File-Saving Strategies
- •Single-File Persistence
- •Multiple-File Persistence
- •Using Property Lists
- •Property List Serialization
- •The First Version of the Persistence Application
- •Creating the Persistence Project
- •Designing the Persistence Application View
- •Editing the Persistence Classes
- •Archiving Model Objects
- •Conforming to NSCoding
- •Implementing NSCopying
- •Archiving and Unarchiving Data Objects
- •The Archiving Application
- •Implementing the BIDFourLines Class
- •Implementing the BIDViewController Class
- •Using iOS’s Embedded SQLite3
- •Creating or Opening the Database
- •Using Bind Variables
- •The SQLite3 Application
- •Linking to the SQLite3 Library
- •Modifying the Persistence View Controller
- •Using Core Data
- •Entities and Managed Objects
- •Key-Value Coding
- •Putting It All in Context
- •Creating New Managed Objects
- •Retrieving Managed Objects
- •The Core Data Application
- •Designing the Data Model
- •Creating the Persistence View and Controller
- •Persistence Rewarded
- •Managing Document Storage with UIDocument
- •Building TinyPix
- •Creating BIDTinyPixDocument
- •Code Master
- •Initial Storyboarding
- •Creating BIDTinyPixView
- •Storyboard Detailing
- •Adding iCloud Support
- •Creating a Provisioning Profile
- •Enabling iCloud Entitlements
- •How to Query
- •Save Where?
- •Storing Preferences on iCloud
- •What We Didn’t Cover
- •Grand Central Dispatch
- •Introducing SlowWorker
- •Threading Basics
- •Units of Work
- •GCD: Low-Level Queueing
- •Becoming a Blockhead
- •Improving SlowWorker
- •Don’t Forget That Main Thread
- •Giving Some Feedback
- •Concurrent Blocks
- •Background Processing
- •Application Life Cycle
- •State-Change Notifications
- •Creating State Lab
- •Exploring Execution States
- •Making Use of Execution State Changes
- •Handling the Inactive State
- •Handling the Background State
- •Removing Resources When Entering the Background
- •Saving State When Entering the Background
- •A Brief Journey to Yesteryear
- •Back to the Background
- •Requesting More Backgrounding Time
- •Grand Central Dispatch, Over and Out
- •Two Views of a Graphical World
- •The Quartz 2D Approach to Drawing
- •Quartz 2D’s Graphics Contexts
- •The Coordinate System
- •Specifying Colors
- •A Bit of Color Theory for Your iOS Device’s Display
- •Other Color Models
- •Color Convenience Methods
- •Drawing Images in Context
- •Drawing Shapes: Polygons, Lines, and Curves
- •The QuartzFun Application
- •Setting Up the QuartzFun Application
- •Creating a Random Color
- •Defining Application Constants
- •Implementing the QuartzFunView Skeleton
- •Creating and Connecting Outlets and Actions
- •Implementing the Action Methods
- •Adding Quartz 2D Drawing Code
- •Drawing the Line
- •Drawing the Rectangle and Ellipse
- •Drawing the Image
- •Optimizing the QuartzFun Application
- •The GLFun Application
- •Setting Up the GLFun Application
- •Creating BIDGLFunView
- •Updating BIDViewController
- •Updating the Nib
- •Finishing GLFun
- •Drawing to a Close
- •Multitouch Terminology
- •The Responder Chain
- •Responding to Events
- •Forwarding an Event: Keeping the Responder Chain Alive
- •The Multitouch Architecture
- •The Four Touch Notification Methods
- •The TouchExplorer Application
- •The Swipes Application
- •Automatic Gesture Recognition
- •Implementing Multiple Swipes
- •Detecting Multiple Taps
- •Detecting Pinches
- •Defining Custom Gestures
- •The CheckPlease Application
- •The CheckPlease Touch Methods
- •Garçon? Check, Please!
- •The Location Manager
- •Setting the Desired Accuracy
- •Setting the Distance Filter
- •Starting the Location Manager
- •Using the Location Manager Wisely
- •The Location Manager Delegate
- •Getting Location Updates
- •Getting Latitude and Longitude Using CLLocation
- •Error Notifications
- •Trying Out Core Location
- •Updating Location Manager
- •Determining Distance Traveled
- •Wherever You Go, There You Are
- •Accelerometer Physics
- •Don’t Forget Rotation
- •Core Motion and the Motion Manager
- •Event-Based Motion
- •Proactive Motion Access
- •Accelerometer Results
- •Detecting Shakes
- •Baked-In Shaking
- •Shake and Break
- •Accelerometer As Directional Controller
- •Rolling Marbles
- •Writing the Ball View
- •Calculating Ball Movement
- •Rolling On
- •Using the Image Picker and UIImagePickerController
- •Implementing the Image Picker Controller Delegate
- •Road Testing the Camera and Library
- •Designing the Interface
- •Implementing the Camera View Controller
- •It’s a Snap!
- •Localization Architecture
- •Strings Files
- •What’s in a Strings File?
- •The Localized String Macro
- •Real-World iOS: Localizing Your Application
- •Setting Up LocalizeMe
- •Trying Out LocalizeMe
- •Localizing the Nib
- •Localizing an Image
- •Generating and Localizing a Strings File
- •Localizing the App Display Name
- •Auf Wiedersehen
- •Apple’s Documentation
- •Mailing Lists
- •Discussion Forums
- •Web Sites
- •Blogs
- •Conferences
- •Follow the Authors
- •Farewell
- •Index
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Text Field Inspector Settings
In the first field, Text, you can set a default value for the text field. Whatever you type here will show up in the text field when your application launches.
The second field, Placeholder, allows you to specify a bit of text that will be displayed in gray inside the text field, but only when the field does not have a value. You can use a placeholder instead of a label if space is tight, or you can use it to clarify what the user should type into this text field. Type in the text Type in a name as the placeholder for our currently selected text field, and then hit return to commit the change.
The next two fields, Background and Disabled, are used only if you need to customize the appearance of your text field, which is completely unnecessary and actually illadvised the vast majority of the time. Users expect text fields to look a certain way. We’re going to skip over these fields, leaving them set to their defaults.
Below these fields are three buttons for controlling the alignment of the text displayed in the field. We’ll leave this setting at the default value of left-aligned (the leftmost button).
Next are four buttons labeled Border Style. These allow you to change the way the text field’s edge will be drawn. The default value (the rightmost button) creates the text field style that users are most accustomed to seeing for normal text fields in an iOS application. Feel free to try all four different styles. When you’re finished experimenting, set this setting back to the rightmost button.
Below the border setting is a Clear Button popup button, which lets you choose when the clear button should appear. The clear button is the small X that can appear at the right end of a text field. Clear buttons are typically used with search fields and other fields where you would be likely to change the value frequently. They are not typically included on text fields used to persist data, so leave this at the default value of Never appears.
The Clear when editing begins checkbox specifies what happens when the user touches this field. If this box is checked, any value that was previously in this field will be deleted, and the user will start with an empty field. If this box is unchecked, the previous value will remain in the field, and the user will be able to edit it. Leave this checkbox unchecked.
After that is a series of fields that let you set the font, font color, and minimum font size. We’ll leave the Text Color at the default value of black. Note that the Text Color popup is divided into two parts. The right side allows you to select from a set of preselected colors, and the left side gives you access to a color well to more precisely specify your color.
The Font setting is divided into three parts. On the right is a control that lets you increment or decrement the text size, one point at a time. The left side allows you to manually edit the font name and size. Finally, click the T-in-a-box icon to bring up a popup window that lets you set the various font attributes. We’ll leave the Font at its default setting of System 14.0.
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Following the Font setting is a control that lets you set the minimum font size that the text field will use for displaying its text. Leave that at its default value for now.
The Adjust to Fit checkbox specifies whether the size of the text should shrink if the text field is reduced in size. Adjusting to fit will keep the entire text visible in the view, even if the text would normally be too big to fit in the allotted space. This checkbox works in conjunction with the minimum font size setting. No matter the size of the field, the text will not be resized below that minimum size. Specifying a minimum size allows you to make sure that the text doesn’t get too small to be readable.
The next section defines how the keyboard will look and behave when this text field is being used. Since we’re expecting a name, let’s change the Capitalization popup to Words. This causes every word to be automatically capitalized, which is what you typically want with names.
The next three popups—Correction, Keyboard, and Appearance—can be left at their default values. Take a minute to look at each to get a sense of what these settings do.
Next is the Return Key popup. The return key is the key on the lower right of the keyboard, and its label changes based on what you’re doing. If you are entering text into Safari’s search field, for example, then it says Search. In an application like ours, where the text fields share the screen with other controls, Done is the right choice. Make that change here.
If the Auto-enable Return Key checkbox is checked, the return key is disabled until at least one character is typed into the text field. Leave this unchecked, because we want to allow the text field to remain empty if the user prefers not to enter anything.
The Secure checkbox specifies whether the characters being typed are displayed in the text field. You would check this checkbox if the text field were being used as a password field. Leave it unchecked for our app.
The next section allows you to set control attributes inherited from UIControl, but these generally don’t apply to text fields and, with the exception of the Enabled checkbox, won’t affect the field’s appearance. We want to leave these text fields enabled so that the user can interact with them. Leave the default settings in this section.
The last section on the inspector, View, should look familiar. It’s identical to the section of the same name on the image view inspector we looked at earlier. These are attributes inherited from the UIView class, and since all controls are subclasses of UIView, they all share this section of attributes. As you did earlier for the image view, check the Opaque checkbox, and uncheck Clears Graphics Context and Clip Subviews, for the reasons we discussed earlier.
Setting the Attributes for the Second Text Field
Next, single-click the second text field in the View window, and return to the inspector. In the Placeholder field, type Type in a number, and make sure Clear When Editing Begins is unchecked. A little farther down, click the Keyboard popup menu. Since we want the user to enter only numbers, not letters, select Number Pad. This ensures that
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the users will be presented with a keyboard containing only numbers, meaning they won’t be able to enter alphabetical characters, symbols, or anything other than numbers. We don’t need to set the Return Key value for the numeric keypad, because that style of keyboard doesn’t have a return key, so all of the other inspector settings can stay at the default values. As you did earlier, check the Opaque checkbox, and uncheck Clears Graphics Context and Clip Subviews.
Creating and Connecting Outlets
We are almost ready to take our app for its first test drive. For this first part of the interface, all that’s left is creating and connecting our outlets. The image view and labels on our interface do not need outlets because we don’t need to change them at runtime. The two text fields, however, are passive controls that hold data we’ll need to use in our code, so we need outlets pointing to each of them.
As you probably remember from the previous chapter, Xcode 4 allows us to create and connect outlets at the same time using the assistant editor. Go into the assistant editor now by selecting the middle toolbar button labeled Editor or by selecting View Assistant Editor Show Assistant Editor.
Make sure your nib file is selected in the project navigator. If you don’t have a large amount of screen real estate, you might also want to select View Utilities Hide Utilities to hide the utility pane during this step. When you bring up the assistant editor, the nib editing pane will be split in two, with Interface Builder in one half and BIDViewController.h in the other (see Figure 4–15). This new editing area—the one showing BIDViewController.h—is the assistant.
Figure 4–15. The nib editing area with the assistant turned on. You can see the assistant area on the right, showing the code from BIDViewController.h.
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You'll see that the upper boundary of the assistant includes a jump bar, much like the normal editor pane. One important addition to the assistant's jump bar is a new set of “smart” selections, which let you switch between a variety of files that Xcode believes are relevant, based on what appears in the main view. By default, it shows a group of files labeled Top Level Objects, including your own source code for the controller class (since it's one of the top-level objects in the nib), as well as headers for UIResponder and UIView, since those are also represented at the top level of the nib. Take a few minutes to click around the jump bar at the top of the assistant, just to get a feel for what’s what. Once you have a sense of the jump bar and files represented there, move on.
Now comes the fun part. Make sure BIDViewController.h is still showing in the assistant (use the jump bar to return there if necessary). Now control-drag from the top text field in the view over to the BIDViewController.h source code, right below the @interface line. You should see a gray popup that reads Insert Outlet, Action, or Outlet Collection (see Figure 4–16). Release the mouse button, and you’ll get the same popup you saw in the previous chapter. We want to create an outlet called nameField, so type nameField into the Name field (say that five times fast!), and then hit return.
Figure 4–16. With the assistant turned on, we control-drag over to the declaration of nameField to connect that outlet.
You now have a property called nameField in BIDViewController, and it has been connected to the top text field. Do the same for the second text field, creating and connecting it to a property called numberField.
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