iOS universal app xcode 4 starter tips - iphone

I'm trying to start a universal app using Xcode and I'm totally lost. I started the universal Window based app from the templates. I'm trying to have a UITableViewController for the iPhone, and a UISplitViewController for the iPad. I see 3 appDelegates, and did read this post http://www.kotancode.com/2011/04/05/ios-universal-apps/ , but I'm still really confused. I started by creating a UIViewController subclass in the iPadAppDelegate folder with a .xib. Nothing is in the file yet. Then in the iPadAppDelegate.h:
#property (nonatomic, retain) IBOutlet HomeViewController_iPad *homeViewController;
Dragged a UIViewController in the MainWindow_iPad.xib, changed the class to HomeViewController, and tried dragging an outlet from the MainWindow to the UIViewController and I am not able to connect the HomeViewController.
I thought I could do somthing like this for the iPhoneAppDelegate as well, but I believe I am missing something from the Universal App Template. Can someone give me some advice on how these 3 appDelegates work and how I can get started? TIA

Universal Apps are really simple once you grasp how they work.
The reason there are three AppDelegates is that you usually have one that is the base class for an iPhone and iPod specific app delegate. The entry-point into your iPhone or iPad Application is based on the configuration in your .plist file, if you select the project in xCode 4 it will show you a graphical configuration dialog that will allow you to change those properties. The so called "Main Interface" is independently selectable for iPhone and iPad in the respective deployment section. The Main Nib file does contain a serialized version of the device specific app delegate, which will then be "woken up" when the application is loading. This process is triggered from your Main() method when
UIApplicationMain(argc, argv, nil, nil)
is called. UIApplicationMain does take care of loading the proper NIB file, based on the device it is run on.
Thats all there is.

Related

How To Port an iPad Application to the iPhone

I have an existing iPad - Application, no I want to make an universal App.
There are many Tutorials with making iPhone Apps universall, but i dont find how to make iPad apps Universal. Is there somebody having experienxce with this?
No Storyboards are used, yust normal xib.
I've readed this tutorial, and porting iPhone apps to universal seems to be better supported by xcode:
http://www.raywenderlich.com/1111/how-to-port-an-iphone-application-to-the-ipad
I would think that the basic idea would be the same, whether you were converting an iPhone app to a universal app, or an iPad app to a universal one(?)
Set the iOS application target to "Universal".
If a view controller, say, XYZViewController has an associated xib for its UI, then - when you create a xib for the iPhone interface - append ~iphone to the name of the iPhone interface and ~ipad to the iPad one, i.e. their file names are
XYZViewController~iphone.xib and XYZViewController~ipad.xib. That way the right xib will be picked up if you pass nil or #"XYZViewController" as nib name to the designated initializer for the view controller. (It's worth noting that the same IBOutlet can be hooked up to the corresponding UI elements in both xibs simultaneously.)
In code, whenever you need to use a different display metaphor that depends on the device type (say you want to use , check for the device type through the test
if ([UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)
{ ... } else { ... }
Another place where you might want to use this test is in VC's shouldautorotatetointerfaceorientation: method.

Updating iPhone app to Universal: IBOutlets

First off, I will say i've spent 6 hours on this topic and have read everything the internet has to provide, which is why i came here.
I have converted to Universal, Xcode created the MainWindow-iPad.xib and everything seems fine.
Here are my questions:
1) What are the naming conventions for new iPad-specific xibs? Xcode created "-iPad" but i believe im supposed to be making them "~ipad". Why the difference?
2) (MOST IMPORTANT) After creating several "~ipad" xibs, Xcode seems to know to load these. So I'll copy the content in say, "RootViewController.xib"
and paste it in "RootViewController~ipad.xib". THIS IS THE PROBLEM: this new ~ipad xib has no outlets or referencing outlets!
I can't link the buttons on my page to anything. How do i do this without having a separate ~ipad .m and .h for everything?
Thank you guys for your help! I'm going to write a tutorial on this once I get this all working.
Just set the class of that ~iPad nib to be the same classname as the cooresponding iPhone nib. This is done in the inspector in Interface Builder. You may have to connect the outlets back up depending on the order you do things. I would think that if you copy the objects from the iPhone nib to the iPad nib AFTER you set the class, then the outlets would stay wired up.

Should I be writing the majority of my code in a controller or the delegate?

I was using Xcode 4.1 and after upgrading to 4.2, things started to become out of date. I am using many examples from different books, such as Big Nerd Ranch Guides, which do not use Storyboards and the Windows-Based Application had been changed to "Empty" Application.
With these new changes, I feel like the books and tutorials I had been using to start have become outdated. In many of these examples, they say to write the methods and variables in the delegate header files for 4.1. With the new 4.2 Xcode, there is an AppDelegate and ViewController. Should I still be writing the methods and class members in the AppDelegate, or should I be now writing them in the Controller file?
I am confused. Does Apple now want us to create our controller and reference it through the delegate?
When your app is run, it creates an instance of UIApplication. You want to know things that only the UIApplication object knows (did we just get switched to the background? did we just open?) so you use the delegate pattern to get it. When you start a new project Apple starts you off with an already-assigned App Delegate. You can open up MainWindow.nib and inspect your App Delegate to see how it is connected to your UIApplication instance (File's Owner, in this case).
In general you only want to put code in there that has to do with the basic functionality of your app. Launch, quit, go to background and come to foreground are when you'll be doing things in the App Delegate.
Most everything else should go in your view controllers or model objects. Since 'delegate' is just a design pattern, your view controllers can be delegates of other objects. For example, if you present a UITableView, you will assign a view controller as it's delegate in order to respond to events such as selection and scrolling. Your app has many delegates, but it only has one App Delegate.
The AppDelegate is really just a "launcher" for your app. Ie: You shouldn't be writing much code in it at all.
If you're concerned with "set up" code, do it in your View Controller, under viewDidLoad.

Proper setup for universal OpenGL ES iPhone/iPad app in XCode 4

I've been trying all morning to setup a univeral OpenGL-ES app with limited success. I can easily get the default OpenGL template app to compile for both devices and run just fine by adding a new XIB file and setting the proper values in it. Where I'm having trouble is figuring out how to give each device it's own unique GUI. Currently both devices use the same ViewController.xib file that is created with the project. How can I create a separate XIB file that uses the same ViewController .h and .m files? Do I need to create a separate AppDelegate class for each device type, or can they be shared?
The standard approach is to have a base AppDelegate class, and then subclass this for each device. Each delegate would then load its own XIB file with the correctly sized UIWindow and add the views.

From iPhone OS to cocoa on OSX

I come from an iPhone OS development background. I'm now trying to write apps for OSX, but I don't understand where cocoa on OSX decides where the program gets control.
I can see the main function, but where does program control go from there? Say for example I want to programatically create a window with an NSView in it once the app has finished launching - how would I do that? There is no app delegate created that I can see, in iPhone OS I would wait for the -(void) applicationDidFinishLaunching:(UIApplication *)application
method to be called. I really don't want to use the Interface Builder or NIB files to setup my window/view. How would I go about this?
It's much the same as the iPhone. In your application controller class, override NSApplication's applicationDidFinishLaunching delegate method. If you used the standard Xcode project template your app controller is already instantiated in your Interface Builder MainMenu.xib and set to be the application's delegate; if not you'll need to drag it in there and set up those connections yourself.
Speaking more generally, an OS X app begins its life in the main method, where Cocoa will automatically set up your application's run loop and load the .xib file you specify in Info.plist. This xib is usually where your application controller is instantiated. By overriding one of the methods such as +initialize, -init, -applicationWillFinishLaunching or -applicationDidFinishLaunching (which all have subtly different behaviors) you can load additional controllers and nibs with objects that interact with the run loop at a future date, so you can continue to execute code after your launch method has finished.