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You’ve now seen all the different types of preference fields that you can use in a settings bundle plist file. To save yourself some typing, you can grab More.plist out of the 12 - AppSettings folder in the project archive that accompanies this book, and drag it into that Settings.bundle window we left open earlier.

TIP: When you create your own child settings views, the easiest way is to make a copy of

Root.plist and give it a new name. Then delete all of the existing preference specifiers except the

first one, and add whatever preference specifiers you need for that new file.

We’re finished with our settings bundle. Feel free to compile, run, and test the Settings application. You should be able to reach the child view and set values for all the other fields. Go ahead and play with it, and make changes to the property list if you want.

TIP: We’ve covered almost every configuration option available (at least at the time of this writing). You can find the full documentation of the settings property list format in the document

called Settings Application Schema Reference in the iOS Dev Center. You can get that document, along with a ton of other useful reference documents, from this page:

http://developer.apple.com/library/ios/navigation/.

Before continuing, copy the rabbit.png and turtle.png icons from the 12 - AppSettings folder in the project archive into your project’s AppSettings folder. We’ll use them in our application to show the value of the current settings.

You might have noticed that the two icons you just added are exactly the same ones you added to your settings bundle earlier, and you might be wondering why. Remember that iOS applications can’t read files out of other applications’ sandboxes. The settings bundle doesn’t become part of our application’s sandbox; it becomes part of the Settings application’s sandbox. Since we also want to use those icons in our application, we need to add them separately to our AppSettings folder so they are copied into our application’s sandbox as well.

Reading Settings in Our Application

We’ve now solved half of our problem. The user can get to our preferences, but how do we get to them? As it turns out, that’s the easy part.

Retrieving User Settings

We’ll take advantage of a class called NSUserDefaults to read in the user’s settings. NSUserDefaults is implemented as a singleton, which means there is only one instance of NSUserDefaults running in your application. To get access to that one instance, we call the class method standardUserDefaults, like so:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

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Once we have a pointer to the standard user defaults, we use it just like an NSDictionary. To get a value from it, we can call objectForKey:, which will return an Objective-C object, such as an NSString, NSDate, or NSNumber. If we want to retrieve the value as a scalar—like an int, float, or BOOL—we can use another method, such as intForKey:, floatForKey:, or boolForKey:.

When you were creating the property list for this application, you added an array of PreferenceSpecifiers. Some of those specifiers were used to create groups. Others created interface objects that the user used to set the settings. Those are the specifiers we are really interested in, because they hold the real data. Every specifier that was tied to a user setting has a Key named Key. Take a minute to go back and check. For example, the Key for our slider has a value of warpfactor. The Key for our Password field is password. We’ll use those keys to retrieve the user settings.

So that we have a place to display the settings, let’s quickly set up our main view with a bunch of labels. Before going over to Interface Builder, let’s create outlets for all the labels we’ll need. Single-click BIDMainViewController.h, and make the following changes:

#import "BIDFlipsideViewController.h"

#define kUsernameKey	@"username"
#define kPasswordKey	@"password"
#define kProtocolKey	@"protocol"
#define kWarpDriveKey	@"warp"
#define kWarpFactorKey	@"warpFactor"
#define kFavoriteTeaKey	@"favoriteTea"
#define kFavoriteCandyKey	@"favoriteCandy"
#define kFavoriteGameKey	@"favoriteGame"
#define kFavoriteExcuseKey	@"favoriteExcuse"
#define kFavoriteSinKey	@"favoriteSin"

@interface BIDMainViewController : UIViewController <BIDFlipsideViewControllerDelegate>

@property (weak, nonatomic) IBOutlet UILabel *usernameLabel; @property (weak, nonatomic) IBOutlet UILabel *passwordLabel; @property (weak, nonatomic) IBOutlet UILabel *protocolLabel; @property (weak, nonatomic) IBOutlet UILabel *warpDriveLabel; @property (weak, nonatomic) IBOutlet UILabel *warpFactorLabel; @property (weak, nonatomic) IBOutlet UILabel *favoriteTeaLabel; @property (weak, nonatomic) IBOutlet UILabel *favoriteCandyLabel; @property (weak, nonatomic) IBOutlet UILabel *favoriteGameLabel; @property (weak, nonatomic) IBOutlet UILabel *favoriteExcuseLabel; @property (weak, nonatomic) IBOutlet UILabel *favoriteSinLabel;

- (void)refreshFields;

@end

There’s nothing new here. We declare a bunch of constants. These are the key values that we used in our plist file for the different preference fields. Then we declare ten outlets, all of them labels, and create properties for each of them. Finally, we declare a method that will read settings out of the user defaults and push those values into the

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various labels. We put this functionality in its own method, because we need to do this same task in more than one place.

Save your changes. Now that we have our outlets declared, let’s head over to the storyboard file to create the GUI.

Creating the Main View

Select MainStoryboard.storyboard to edit it in Interface Builder. When it comes up, you’ll see the main view on the left and the flipside view on the right, connected by a segue. Notice that the background of the main view is dark gray. Let’s change it to white.

Single-click the View belonging to the Main View Controller, and bring up the attributes inspector. Use the color well labeled Background to change the background to white. Note that the color well also functions as a popup menu. If you prefer, use that menu to select White Color.

Put the layout area’s dock in list mode by clicking the small triangle icon, if it’s not already in that mode. In the dock, in the Main View Controller Scene, expand Main View Controller, and then within that, expand View. This reveals an item called Button (see Figure 12–29).

Figure 12–29. In the dock, locate the Main View Controller Scene and expand Main View Controller, and then expand View and find the Button item.

TIP: Got a complex Interface Builder list mode hierarchy that you want to open, all at once?

Instead of expanding each of the items individually, you can expand the entire hierarchy by

holding down the option key and clicking any of the list’s disclosure triangles.

The Button, situated at the lower-right corner of the view, contains an icon that’s mostly white, and is therefore hard to see against the white background. We’re going to change this icon so it will look good on a white background. With the Button selected, bring up the attributes inspector. Change the button’s Type from Info Light to Info Dark.

Now we’re going to add a bunch of labels to the View so it looks like the one shown in Figure 12–30. We’ll need a grand total of 20 labels. Half of them will be static labels that are right-aligned and bold; the other half will be used to display the actual values retrieved from the user defaults and will have outlets pointing to them.

Use Figure 12–30 as your guide to build this view. You don’t need to match the appearance exactly, but you must have one label on the view for each of the outlets we

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declared. Go ahead and design the view. You don’t need our help for this. When you’re finished and have it looking the way you like, come back, and we’ll continue. Just so you know, all our labels used 15-point System Font (or System Font Bold), but feel free to go wild with your own design.

Figure 12–30. The View window in Interface Builder showing the 20 labels we added

The next thing we need to do is control-drag from the Main View Controller icon (which represents File’s Owner in the storyboard) to each of the labels intended to display a settings value. You will control-drag a total of ten times, setting each label to a different outlet. Once you have all ten outlets connected to labels, save your changes.

Updating the Main View Controller

In Xcode, select BIDMainViewController.m, and add the following code at the beginning of the file:

#import "BIDMainViewController.h"

@implementation BIDMainViewController

@synthesize usernameLabel; @synthesize passwordLabel; @synthesize protocolLabel; @synthesize warpDriveLabel; @synthesize warpFactorLabel; @synthesize favoriteTeaLabel; @synthesize favoriteCandyLabel; @synthesize favoriteGameLabel;

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@synthesize favoriteExcuseLabel; @synthesize favoriteSinLabel;

- (void)refreshFields {

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; usernameLabel.text = [defaults objectForKey:kUsernameKey]; passwordLabel.text = [defaults objectForKey:kPasswordKey]; protocolLabel.text = [defaults objectForKey:kProtocolKey]; warpDriveLabel.text = [defaults boolForKey:kWarpDriveKey]

? @"Engaged" : @"Disabled"; warpFactorLabel.text = [[defaults objectForKey:kWarpFactorKey]

stringValue];

favoriteTeaLabel.text = [defaults objectForKey:kFavoriteTeaKey]; favoriteCandyLabel.text = [defaults objectForKey:kFavoriteCandyKey]; favoriteGameLabel.text = [defaults objectForKey:kFavoriteGameKey]; favoriteExcuseLabel.text = [defaults objectForKey:kFavoriteExcuseKey]; favoriteSinLabel.text = [defaults objectForKey:kFavoriteSinKey];

}

.

.

.

- (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated];

[self refreshFields];

}

.

.

.

Also, let’s be good memory citizens by inserting the following code into the existing viewDidUnload method:

- (void)viewDidUnload { [super viewDidUnload];

//Release any retained subviews of the main view.

//e.g. self.myOutlet = nil;

self.usernameLabel = nil; self.passwordLabel = nil; self.protocolLabel = nil; self.warpDriveLabel = nil; self.warpFactorLabel = nil; self.favoriteTeaLabel = nil; self.favoriteCandyLabel = nil; self.favoriteGameLabel = nil; self.favoriteExcuseLabel = nil; self.favoriteSinLabel = nil;

}

When the user is finished using the flipside view where some preferences can be changed, our controller will be notified of the fact. When that happens, we need to make sure our labels are updated to show any changes. Add the following line of code to the existing flipsideViewControllerDidFinish: method:

- (void)flipsideViewControllerDidFinish: (BIDFlipsideViewController *)controller {

[self refreshFields];

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