How to preserve NSLayoutConstraints when rearranging hierarchy - ios

I made a custom UIView and made the UI with an XIB and the hierarchy is like below
The highlighted view has many constraints hooked with its superview. Now I want to make the view the subview of the vibrancy effect view, AND preserve the constraints between the highlighted view and the current superview.
Right now if I just drag the view inside, the constraints are removed.
Does anyone know how I can achieve this?

Related

How can i resize the parent view after changing the constraints of child views?

I have a pop up view which is loading from a xib file.In that file there are couple of views, labels and buttons. For specific condition i have hide couple of views and buttons and its working but total height of the parent view of those views and buttons is not changing.
I have set the height constraints of the parent view and tried to change the constant but its not updating.
self.translatesAutoresizingMaskIntoConstraints = YES;
I want to resize the parent view after hide the parent view.
Main window
Changed window after constraints
Hiding the view does not remove it from its parents. It just changes its visibility. The view still remains in the hierarchy. To achieve what you want to do the following:
Constraint the view above and view below the view you want to hide with a lower priority.
remove the view(the one you want to hide) from its superview
I hope this helps

Why is my UIView drawing behind my other views?

I have a UIView which is opened and closed by a button onscreen. I am positioning it over a scrollable custom text area which is a bunch of UILabels added to a UIScrollView.
I've made sure that it is added last in my view hierarchy, in the xib. I have also tried calling bringSubviewToFront, and have even removed the UIView from the parent view and re-added it after doing the layout.
Nothing that I have tried prevents it from being drawn behind this UIScrollView. I have verified that my UIView is actually the last UIView in the hierarchy by looking at the view hierarchy in the debugger at runtime.
The UIView in question, shown as a smiley in the picture here, has children. It has a 3x3 grid of invisible UIButtons, and a UIImageView to draw the image, which is normally something other than the smiley. But I am operating on the parent UIView, not the children.
Is there anything I can try, to help diagnose this? To recap, I have done all the following:
the UIView is added last in my view hierarchy, after the UIScrollView. It is a child of the same parent (the root view) as the scroll view - hence, a sibling view of the scroll view.
after doing the layout, I've tried [self.view bringSubviewToFront:myView]
after doing the layout, I've tried doing [myView removeFromSuperView] followed by [self.view addSubview:myView].
The latter two operations are performed at the very end of my layout method.
Any ideas?

UICollectionVIew inside UIView adds a huge amount of padding to the top of the collectionView

I am trying to add collection view to UIView and there is a problem that doesn't make any sense. Screenshot. I made the background color of the collection view, to make show the view area more clearly.
If I add the collection view straight to the controller (just like in UICollectionViewController), the top padding doesn't exist.
In this example, I have autolayouted the collection view to resize to the whole view but the problem existed the moment I added collection view to the UIView.
Also, if I add another collection view right after this view, there items start from the top, without any margins.
If there is anything else you need me to provide, I will do it. I think this is a storyboard bug or something because there are no insets, in the view's attributes.

Embedding a view with subviews in another parent view and keeping constraints (IB)

I have a scene in storyboard with several subviews for which I already set a lot of constraints in Interface Builder. These subviews are directly children of the view controller's view. Now I realize that I need the whole view + subviews be contained in a full-screen UIScrollView to handle scrolling of the content when the keyboard is shown. But if I simply move all the subviews inside the scroll view, I loose the constraints that referred to "superview" and I get a mess.
Is there any way to migrate the constraints regarding the previous "superview" (view controller's view) to the new parent scroll view (which is the child of the "superview")?
Thanks
No there is no way to do this. The constraints between the view controller's view and the subviews are as you know broken when you move your subviews into another subview/view. AFIAK the biggest reason for this is you could end up with subviews that have constraints which relate to views on longer in their
view hierarchy which is a violate of the constraints lay out system.

Rearrange UIView Subviews if a Subview is removed in Auto Layout

I am in a need of implementing a drag and drop controller in Full-Auto Layout environment.
I have achieved the dragging and dropping successfully, but the issue is if I drag a subview from another view the other related subviews behave weirdly,
as an example the subviews are laid out horizontally in scrollview are related to each other, so if I remove a subview the other views should rearrange them self automatically.
Regards,
Dhanesh.
when you doing the design part of xib uncheck the autolayout.
After completing the designing then go towards to autolayout and arrange the view using constraint adding.

Resources