CODEWITHSUNDEEP
iphoneobjective-cios
user1054941
user1054941

Reputation: 43

UIView layoutSubviews not being called

Using Xcode 4.2/iOS5.0

I have a viewController and an associated viewController.xib. The viewController is set up as the .xib's file's owner. It is invoked from a UINavigationController.

I am attempting some manual layout when the device is rotated portrait/landscape

As I understand it the UIView method to override is

- (void)layoutSubviews;

this is where you do the layout

But - as with drawRect - you do not call this directly, it is invoked when appropriate by iOS

Instead you call setNeedsLayout...

So I have this in the ViewController

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)
         fromInterfaceOrientation {
   [[self view] setNeedsLayout];
 }

and in the same ViewController I have this

- (void)layoutSubviews {
    //.manual override of automatic layout on rotation
NSLog(@"layoutSubviews");
 }

However layoutSubviews does not get called and I don't understand why.

Here is a clue... If I call layoutSubviews directly as [self layoutSubviews]

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)
         fromInterfaceOrientation {
   [self layoutSubviews];
 }

it does trigger

But if I call it as [[self view] layoutSubviews] it does not

So it appears that the view and it's controller are not wired up correctly?

Upvotes: 4

Views: 9244

Answers (2)

user1122069
user1122069

Reputation: 1807

For the general question, this also happens when you forget to call addSubview with your subview on the superview.

Upvotes: 0

Lily Ballard
Lily Ballard

Reputation: 185681

Your problem here is you've implemented -layoutSubviews on your view controller, instead of on your view. It will never be called this way. -layoutSubviews is a mechanism by which a custom view can lay out its own subviews (e.g. a UIButton that has a UIImageView for the image and a UILabel for the label, and uses -layoutSubviews to ensure the imageview and label are all positioned correctly). It's not a mechanism by which a view controller can control the layout of its views.

If you want to change layout on rotation, then you should just go ahead and set up the new layout inside of -didRotateFromInterfaceOrientation:.

Upvotes: 6

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