I'd like to be able to layout my view controller in code but see the layout displayed in interface builder.
I know I can create a UIView subclass, make that IBDesignable, and assign it to the view controller's view, but this would require that I make all other subviews properties of this UIView subclass instead of properties of the view controller.
The real desire is to be able to layout my view controllers in code but quickly see any changes without rebuilding the project. If this is possible with playgrounds instead, an answer describing how to do that would also be appreciated.
Thanks for any suggestions.
I found a workaround to test view controller layout using IBDesignable.
1.Layout your view controller in code just as you'd do normally
2.Create an IBDesignable UIView subclass and add the view controller's view as a subview.
3.Create a xib and set the class of its view to the subclass you created in step 2
To elaborate on step 2, your IBDesignable's initWithFrame: method may look like
{
self = [super initWithFrame:frame];
MyViewController *viewController = [MyViewController alloc] init];
viewController.view.frame = self.bounds;
[self addSubview:viewController.view];
return self;
}
So beyond this initWithFrame method, all of your layout code can be handled by your view controller. You may want to pass data to your view controller in your subview's prepareForInterfaceBuilder method.
In order to layout you own classes in Xcode you need first to import then in your swift playground: here more information.
After you do that, it's came the "tricky" part. In order to make your how class debuggable and visibile in playground, your class must conform to the protocol: CustomPlaygroundQuickLooacable:
Here there is a quick example from the WWDC:
By implementing this protocol, you're basically telling playground how to represent you hown class. I haven't fond any better solution yet.
Related
Here is my project:
It only crashes in iOS8.
I have 5 view controllers:rootViewController,A,B,C and D.Every view controller has a button that present another view controller except D. Evert time presenting a view controller, the Manager singleton object will add the presented view controller into an array. The last view controller D, which has a dismiss button, will use the array to dismiss view controller,and here's the code:
while ([Manager sharedManager].viewCont.count) {
UIViewController *viewController = [[Manager sharedManager].viewCont lastObject];
[viewController dismissViewControllerAnimated:NO completion:nil];
[self removeViewCon];
}
But I meet a crash,which shows:
I use some manage object because I want to manage the view controllers in some case.
My question is why this crash occurs when in "while" statement? Is it about runloop or iOS8 has some features like UIPresentationController that will not allow this case? And how to fix this?
Thanks in advance.
I just hit this also. It seemes the UIPresentationController crashes if it's presenting view disappears before it is done using it. One fix is to keep the view controller around a little bit longer.
I want to programmatically move from a viewController to another using Apple's new Swift language. I've googled and read through the docs, and I see how to use a single ViewController. Does anyone have an example or documentation on how to switch between View Controllers?
There are many ways to do this detailed in the class documentation for UIViewController.
Example 1
Here is an example of using the -presentViewConroller: method (assuming this code is written in a UIViewController subclass):
var secondViewController = UIViewController() //create your second view controller.
self.presentViewController(secondViewController, true, NULL)
Example 2
This is how you would present the second UIViewController via storyboards (again assuming this code is written in a UIViewController subclass):
self.preformSegueWithIdentifier("segueIdentfier", self);
To create from code a parent/child relationship between 2 view controllers basically it's just matter of doing something like:
[self addChildViewController:childViewController];
[self.view addSubview:childViewController.view];
where self is the parent view controller.
But, what if I want to create the same relationship completely from Interface Builder?
Or in other words: is there a way to re-create the behavior of the method addChildViewController using Interface Builder?
I didn't find a lot of documentation about that, here is an old unresolved post about the topic: https://devforums.apple.com/message/455758#455758
Without properly setting up the addChildViewController relationship, none of the rotation methods are forwarded to my child view controller, here where my question come from.
This is what I've done in IB:
drag and dropped a "View Controller" object from the "Object Library" panel into the "Objects" panel
in the identity inspector I've changed its class to my UIViewController subclass ("Items View Controller")
connected the view outlet to the controller
connected all the other required outlets to the controller (List name, Table View)
The first "View" object in the picture is the view of my parent view controller, instead the highlighted "View" is the view of the child view controller ("Item View Controller").
The container controller also retain its child instance through an additional IBOutlet:
#property (nonatomic, strong) IBOutlet ItemsViewController *itemsViewController;
Thanks
Update 1: If I manually set the parent/child relationship in viewDidLoad of the container controller, all the rotation methods are correctly forwarded to the child.
[self addChildViewController:self.itemsViewController];
But I don't really know if this is the correct way of doing that, since I would like to do all using IB.
Update 2: Thanks to #micantox for his hint to use the "Container View" in the Object Library, I have converted my xib file to a Storyboard and now the child view controller is added to its parent, so I don't have to add it manually from code with addChildViewController and the rotation methods are forwarded as expected.
"Container View" basically implements the embed segue and is supported only from iOS 6.
This is an updated screenshot from my Storyboard:
The right way of creating container views for child view controllers is through the use of the object "Container View" in the Object Library. Dragging one in your View Controller's scene will create a new scene for the child view controller that can be managed separately from the the parent view controller.
Also, if you're trying to create an embed segue to an existing view controller in your storyboard, control-drag from the container view, not the container VC, to the VC you want to embed.
A very simple way to do it is just instantiate the child view controller by referencing its storyboard ID:
UITableViewController *childViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"childViewController"];
[self addChildViewController:childViewController];
[self.view addSubview:childViewController.view];
That way, you can build both view controllers in interface builder. You can set the storyboard ID in interface builder: select the view controller and you'll see a field for it in the identity inspector.
I got a very interesting problem here. My iPhone app has an UITabbarController as rootViewController in the AppDelegate.
If the app is opened the first time, it must be configured basically. For this purpose I create an UINavigationController and tell the tabbarController to present it modally:
firstRun = [[firstRunViewController alloc] init];
navCtrl = [[UINavigationController alloc] initWithRootViewController:firstRun];
[[self tabBarController] presentModalViewController:navCtrl animated:NO];
When the configuration is done, I'd like to get rid of the firstRunViewController. I'm using this technique very often, using -dismissModalViewControllerAnimated:.
But in this constellation this doesn't work. It doesn't matter from what controller I'm calling the dismiss.
I tried it via the tabbarController, the rootViewController, the currently active viewController, of cause self and several other controllers.
EVERY TIME I call -dismissModalViewControllerAnimated: I get this exception:
'UIViewControllerHierarchyInconsistency', reason: 'presentedViewController for controller is itself on dismiss for: <UINavigationController:…
Can anybody help? Thanks in advance, with kind regards, Julian
EDIT
In my AppDelegate I'm using a UITabbarController as rootViewController for the main window:
self.window.rootViewController = self.tabBarController;
[self.window makeKeyAndVisible];
Then I'm creating an UINavigationController and tell the UITabbarController to present the modalViewController:
UINavigationController *navCtrl = [[UINavigationController alloc] initWithRootViewController:firstRun];
[[self tabBarController] presentModalViewController:navCtrl animated:NO];
When I now call -dismissModalViewControllerAnimated: on the firstViewController I'm getting the error from above.
In my opinion you are abusing UITabbarController. This class, even though a subclass of UIViewController, does not really use much of the UIViewController infrastructure.
What you want is a slight extension of what you have now. Create a new UIViewController subclass in your appDelegate, and add it as the single object to an array, and set the tabBar's viewControllers to this array. Set your subclass' hidesBottomBarWhenPushed to YES so it hides the tab bar when it becomes visible.
Now your app will launch and your UIViewController subclass will become the frontmost view. You can make this view the one you wanted to present modally, or you can present that view from your subclass using some kind of animation. Oh, and if you use the launch view as the background image for your subclass, you can really make this a smooth transition - I do this now.
When your modal view is done, then you can instantiate whatever views you want to then display, and set the UITabBarController to use those views with tabBarController.viewControllers (or the animated version). Poof, you UIViewController will get replaces (and under ARC just disappear).
I don't have a chance to test my hypothesis, but I suspect that this issue could depend on the fact that you are presenting the modal view too early, whereby too early means before the main window has had the chance to set up the tab bar controller. So, I would suggest this changes:
create a method to instantiate your navigation controller:
- (void)initializeAndPresentNavigationController {
UINavigationController *navCtrl = [[UINavigationController alloc] initWithRootViewController:firstRun];
[[self tabBarController] presentModalViewController:navCtrl animated:NO];
}
instead of presenting the navigation controller directly from appDidFinishLaunching, call the above method asynchronously:
[self performSelector:#selector(initializeAndPresentNavigationController) withObject:nil afterDelay:0.0];
Here the trick of calling the method as I do in 2 is that the call to initializeAndPresentNavigationController will be simply pushed on the main loop, and executed after your app has had the possibility to build its initial UI.
Hope it works for you.
I finally found the answer myself!
I just couldn't see the wood for the trees! I'm quite happy right now! :)
I did really silly things: In the last viewController of the setup viewControllers I had to change the tabars viewControllers corresponding to whether the user is administrator or not. So I did:
appDelegate.tabBarController.viewControllers = [NSArray arrayWithObjects:appDelegate.readState,
appDelegate.navCtrl,
appDelegate.settings, nil];
You can see that I was adding the AppDelegate's "navCtrl" to the tabbar's viewControllers. So I was trying to dismiss a viewController I just added to the parentViewControllers (UITabbarController) sub-controllers.
Dismissing something I want to present just in the same moment is NOT advisable! :))
I'm trying to "bookmark" (sort of) an object from one UIViewController so that it then shows on a different UIViewController. Currently, the only way I can get this to work is if I either push to the UIViewController that will display the bookmarks or if I perform a segue which is basically the same thing.
Is there a different approach to this?
if you just want to send a variable (without loading the view). This is how I do it.
DetailViewController *detailvc = [[[DetailViewController alloc] init] autorelease];
detailvc.event = [self.fetchedResultsController objectAtIndexPath:indexPath];
And another type of segue I've been doing (without the need of the whole function) i just ask the storyboard to go...
[self.storyboard instantiateViewControllerWithIdentifier:#"detailViewController"];
Just don't forget to name the identifier in the sotyboard, properties, identifier.
Hope it helps...
I've been having some trouble re-learning everything with the storyboard as well.