What is Causing this Unwanted Content Inset with UITextView in iOS 8 (not there in iOS 7)?

Question

I've been creating UITextView s programatically, using auto layout, in iOS 7. Something like this:

_textView = [UITextView new];
_textView.translatesAutoresizingMaskIntoConstraints = NO;
_textView.font = [UIFont systemFontOfSize:18.0];
_textView.delegate = self;
[self.view addSubview:_textView];

In addition to the other constraints I've created, I have this one for the bottom of the text view:

_textViewBottomConstraint = 
       [NSLayoutConstraint constraintWithItem:_textView
                                                     attribute:NSLayoutAttributeBottom
                                                     relatedBy:NSLayoutRelationEqual
                                                        toItem:self.bottomLayoutGuide
                                                     attribute:NSLayoutAttributeTop
                                                    multiplier:1.0
                                                      constant:0.0];

[self.view addConstraint:_textViewBottomConstraint];

So that I can change the constraint when the keyboard shows:

- (void)keyboardDidShow:(NSNotification*)sender
{
    CGRect keyboardFrame = 
                        [sender.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGRect convertedFrame = 
                        [self.view convertRect:keyboardFrame fromView:self.view.window];
    _textViewBottomConstraint.constant = -convertedFrame.size.height;
    [_textView layoutIfNeeded];
}

That's all been working fine...

Problem

I've just switched over to Xcode 6 and iOS 8 (late, I know) - and the text within the UITextView now has an inset at the top. Eg (Text view background is yellow):

What's causing the inset? Is it connected to NSTextContainer and textContainerInset ?

• Is working with NSTextContainer and textContainerInset the correct way to use UITextView from iOS 7 and onward?
• Does it have to be done that way in iOS 8?

If yes, I'd appreciate some guidance for programatically creating a UITextView along with the necessary NSTextContainer and NSLayoutManager ; then setting textContainerInset . (I'll be using auto layout, programatically).

Thanks.

Answer 1

I think automaticallyAdjustsScrollViewInsets works a bit differently in iOS 8. In 7, it only applied if the controller's view property was a scrollView. In 8, it seems to apply to scroll views that are subviews of the controllers' view.

Answer 2

It's the contentInset from the UIViewController .

It seems that with iOS 8, with my UITextView as it is within my UIViewController , there's a need to explicitly set:

self.automaticallyAdjustsScrollViewInsets = NO;

Without explicitly setting that, I've checked the difference between a physical iPhone 5s running iOS 7 and the Simulator iPhone 5s running iOS 8.

Here is some log output, checking the top value for textContainerInset , contentInset and scrollIndicatorInset . In each case, after viewDidLoad and keyboardDidShow .

iPhone 5s Device running iOS 7 :

2014-09-12 07:55:01.244 Alter[19147:60b] viewDidLoad
2014-09-12 07:55:01.249 Alter[19147:60b] textContainerInset Top: 8.000000
2014-09-12 07:55:01.252 Alter[19147:60b] contentInset Top: 0.000000
2014-09-12 07:55:01.253 Alter[19147:60b] scrollIndicatorInset Top: 0.000000

2014-09-12 07:55:02.515 Alter[19147:60b] keyboardDidShow
2014-09-12 07:55:02.516 Alter[19147:60b] textContainerInset Top: 8.000000
2014-09-12 07:55:02.516 Alter[19147:60b] contentInset Top: 0.000000
2014-09-12 07:55:02.516 Alter[19147:60b] scrollIndicatorInset Top: 0.000000

Simulator iPhone 5s (or 6, or 6 Plus) running iOS 8 :

2014-09-12 07:55:39.395 Alter[2120:109535] viewDidLoad
2014-09-12 07:55:39.395 Alter[2120:109535] textContainerInset Top: 8.000000
2014-09-12 07:55:39.396 Alter[2120:109535] contentInset Top: 0.000000
2014-09-12 07:55:39.396 Alter[2120:109535] scrollIndicatorInset Top: 0.000000

2014-09-12 07:55:39.939 Alter[2120:109535] keyboardDidShow
2014-09-12 07:55:39.939 Alter[2120:109535] textContainerInset Top: 8.000000
2014-09-12 07:55:39.939 Alter[2120:109535] contentInset Top: 64.000000
2014-09-12 07:55:39.939 Alter[2120:109535] scrollIndicatorInset Top: 64.000000

To answer my own question, I don't need to manually set up the NSTextContainer and the NSLayoutManager . Though it might be better to start using the textContainerInset approach, I have the option to adjust the frame if I set this in the parent view controller:

self.automaticallyAdjustsScrollViewInsets = NO;