UIStackView: Loading views from xib and updating height constraint of subView did not reflecting any changes?

Question

I have the following hierarchy in my application

- UIScrollView
- UIStackView
 - UIView 1  // load with xib and added in arrangedSubviews
   - UIScrollView 1.1 // horizontal scrolling, fixed height constraint 38
   - UIView 1.2 // called it childView. has fixed height 0 (I load the view from xib and add it here dynamically and update its height)
     - UIView 1.2.1 // called it New View
 - UIView 2
 - UIView 3

So my problem is when I have loaded a view from xib and added it to UIView1.2 also increased height constraint 0 to a height of newly added sub-view but nothing will happen.UIView1.2height did not update expectedly .

self.constraintChildViewHeight.constant = 95;
[self layoutIfNeeded];

NewView *newView = (NewView *)[[[NSBundle mainBundle]loadNibNamed:NSStringFromClass([FieldPhotoView class]) owner:self options:nil]objectAtIndex:0];
[newView setTranslatesAutoresizingMaskIntoConstraints:false];
[self.childView addSubview:newView];
[self applyConstraintsToParent:self.childView andSubView:newView];

Method

- (void)applyConstraintsToParent:(UIView *)parentView andSubView:(UIView *)subView {
//constraints

NSLayoutConstraint *leading = [NSLayoutConstraint constraintWithItem:subView attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:parentView attribute:NSLayoutAttributeLeading multiplier:1.0 constant:0];

[parentView addConstraint:leading];

NSLayoutConstraint *trailing = [NSLayoutConstraint constraintWithItem:subView attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:parentView attribute:NSLayoutAttributeTrailing multiplier:1.0 constant:0];


[parentView addConstraint:trailing];

NSLayoutConstraint *top = [NSLayoutConstraint constraintWithItem:subView attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:parentView attribute:NSLayoutAttributeTop multiplier:1.0 constant:0];

[parentView addConstraint:top];

NSLayoutConstraint *bottom = [NSLayoutConstraint constraintWithItem:subView attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:parentView attribute:NSLayoutAttributeBottom multiplier:1.0 constant:-8];

[parentView addConstraint:bottom];

NSLayoutConstraint *equalWidth = [NSLayoutConstraint constraintWithItem:subView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:parentView attribute:NSLayoutAttributeWidth multiplier:1.0 constant:0];


[parentView addConstraint:equalWidth];

leading.active = true;
trailing.active = true;
top.active = true;
bottom.active = true;
equalWidth.active = true;
}

#Edit1 - Child view constraints

#Edit2 - For better understanding, I want to achieve this functionality programmatically using xib's(In UIStoryBoard is just working fine.)

Interleave

Still not all the constraints mentioned. Do you have bottom constraint connecting child view and its' superview? What is self in your code? (Now can just say that you definitely don't need the equalWidth constraint, cause widths are already have to be equal according to leading and trailing constraints) – Malay

Okay, I will put another image for child view constraints and self is UIView 1 which is added to UIStackView. Can you please see my view hierarchy? – Interleave

@AntonFilimonov Please see my updated question. – Interleave

Tried to do the same - everything works as expected.. Do you get any warnings in console? Maybe some constraints are in conflict. – Malay

No, There is not a single warning. but it's not working in my case. – Interleave

@AntonFilimonov Can you please share your working code? – Interleave

check this out github.com/anton-filimonov/StackViewTest hope this will help you – Malay

@AntonFilimonov incompatible project version? – Interleave

@Vishal16 I suggest using "Debug View Hierarchy" to check every view properties and layout before continue. To make sure that it REALLY doesn't work. If it doesn't work, then which layout property is WRONGLY set or may you miss any constraints between UIView 1 & 1.2 ? Good luck ;) raywenderlich.com/1879-view-debugging-in-xcode-6 – Ehudd

@HoaiDam I will do that and update you. Thanks for the suggestion. – Interleave

What Xcode version do you use? Changed project format to Xcode 8.0 compatible – Malay

Seems like it'd be easier if you share your not working sample. Because I've made almost exactly what's on your gif except that there was the only one view with expanding child. And it worked as expected – Malay

@AntonFilimonov are you using xib's? – Interleave

Yes I load view which contains scroll view and the other view with changed height (like view 1 in your question) from xib.Actually the last possible case is that the view, you insert to view 1.2 (the newView, but we have no idea what's inside its' xib file) has constraints that conflict with others. But in this case there should be warnings about unsatisfiable constraints in console log.. – Malay

@AntonFilimonov Place your code in the answer I will mark it accepted. – Interleave

@Vishal16 Finally got to do that – Malay

Answer 1

From your question what i understood is that you are not able to scroll your content in the scrollview 1.1.

Try the following steps :

1. For the scrollview 1.1

   • give top, bottom,leading, trailing constraints w.r.t View1.
   • give scrollview height constraint = 38

2. For the childview UIView 1.2

   • give top, bottom,leading, trailing constraints w.r.t scrollview1.1
   • pin childview w.r.t View1 for leading & trailing edges
   • give childview height constraints
   • give childview vertically center constraint.

3. For the newView UIView 1.2.1

   • Load view from nib.
   • Add it to the childview
   • Set its constraints - top, bottom, leading & trailing w.r.t childview.

This will make your content scrollable.

I have shared a sample project here: https://github.com/Abhie87/StackExchangeSample

Hope this will be helpful.

Springtime

Failed to load project at '...Downloads/StackExchangeSample-master/StachExchangeBounty.xcodeproj', incompatible project version. Which version of Xcode? – Interleave

Okay, Let me try. but if you can see my question I have already done as your solution. – Interleave

I have edited my answer a bit. You can try that small change – Springtime

I saw your implementation it's a bit confusing. Why are you adding childView in UIScrollView. It's by default has a parent scrollview. So that I only want to increase childView height when it's subview height changes. – Interleave

also you are providing a fixed height constraint 200. Why? – Interleave

My answer was based on what I understood from your problem statement. Height is set to 200 just as dummy value. If u have provided the screenshots of expected and current screen then it would have been easy to understand problem. No issues. Hope u would have got it resolved. – Springtime

Answer 2

Tried to do the same and it worked as expected. What I did:

• Initial views hierarchy looks like this:
• Stack view constraints are on the next image:
• Each view in stack view has only its' height set by constraint (the button in last view I use to add/remove the new view to the stack view at index 0)
• The view to add is loaded from .xib file called SomeView.xib view hierarchy and constraints for which are on the next image (constraint called View Height Constraint is set to 1 and is changed to 95 when SomeView is added to the stack view):

The function that is called when the button is tapped looks like this:

- (IBAction)buttonTap:(UIButton *)sender {
    if (self.theView) {
        [self.stackView removeArrangedSubview:self.theView];
        [self.theView removeFromSuperview];
        self.theView = nil;
    } else {
        self.theView = [[[NSBundle mainBundle] loadNibNamed:@"SomeView" owner:nil options:nil] firstObject];
        self.theView.translatesAutoresizingMaskIntoConstraints = NO;
        [self.stackView addSubview:self.theView];
        [self.stackView insertArrangedSubview:self.theView atIndex:0];
        self.theView.viewHeightConstraint.constant = 95;
    }
}

Hope this will give you any suggestions in how to fix your situation

Malay