Using Xcode 8.0 (8A218a)
I get "Height is ambiguous." even though (in my opinion) I've got constraints all along the Y-axis.
Both of the two subviews inside the view have a height (one have height as constraint, and one as intristic content size).
See the image below for what the "Debug View Hierarchy" says.
The constraints are created in code with the following code:
label is UILabel, underline is UIView
label.translatesAutoresizingMaskIntoConstraints = false
underline.translatesAutoresizingMaskIntoConstraints = false
addSubview(label)
addSubview(underline)
label.topAnchor.constraint(equalTo: topAnchor).isActive = true
label.leftAnchor.constraint(equalTo: leftAnchor).isActive = true
label.rightAnchor.constraint(equalTo: rightAnchor).isActive = true
label.bottomAnchor.constraint(equalTo: underline.topAnchor, constant: -5).isActive = true
underline.leftAnchor.constraint(equalTo: leftAnchor).isActive = true
underline.rightAnchor.constraint(equalTo: rightAnchor).isActive = true
underline.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
underline.heightAnchor.constraint(equalToConstant: 2.0).isActive = true
Here's sample-project extracted from the problematic project:
https://github.com/everlof/LayoutIssue
Related
I have labels and an image. I want labels above image. And image without leading and trailing margin constraints.
I have tried the following constraints but can't seem to get it right. And the row height for the cells doesn't adjust accordingly in landscape mode.
addSubview(videolabel1)
videolabel1.translatesAutoresizingMaskIntoConstraints = false
videolabel1.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 20).isActive = true
videolabel1.trailingAnchor.constraint(equalTo: trailingAnchor
, constant: 20).isActive = true
videolabel1.topAnchor.constraint(equalTo: topAnchor, constant: 20).isActive = true
videolabel1.bottomAnchor.constraint(equalTo: bottomAnchor, constant: 20).isActive = true
addSubview(image)
image.translatesAutoresizingMaskIntoConstraints = false
image.leadingAnchor.constraint(equalTo: leadingAnchor).isActive = true
image.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
image.heightAnchor.constraint(equalToConstant: 150).isActive = true
image.widthAnchor.constraint(equalTo: videoimage.heightAnchor
, multiplier: 16/9).isActive = true
image.topAnchor.constraint(equalTo: videodate.bottomAnchor, constant: 12).isActive = true
image.bottomAnchor.constraint(equalTo: bottomAnchor, constant: 12).isActive = true
Try using UIStackView's when you want to arrange views in a horizontal or vertical fashion. The UIStackView can take care of most constraints for you.
You can try adding a parent UIStackView with vertical orientation, that contains another UIStackView with horizontal orientation (this UIStackView will contain two UILabel's), followed by the UIImageView, and another UILabel.
parentStackView = UIStackView()
parentStackView.axis = .vertical
parentStackView.distribution = .equalSpacing
parentStackView.translatesAutoresizingMaskIntoConstraints = false
self.contentView.addSubview(parentStackView)
parentStackView.topAnchor.constraint(equalTo: self.contentView.topAnchor).isActive = true
parentStackView.widthAnchor.constraint(equalTo: self.contentView.widthAnchor, multiplier: 1).isActive = true
parentStackView.heightAnchor.constraint(equalTo: self.contentView.heightAnchor, multiplier: 1).isActive = true
parentStackView.isLayoutMarginsRelativeArrangement = true
parentStackView.addArrangedSubview(stackView)
stackView.axis = .horizontal
stackView.distribution = .equalSpacing
stackView.spacing = 10
stackView.addArrangedSubview(label)
label.text = "First Label";
stackView.addArrangedSubview(label2)
label2.text = "Second Label";
parentStackView.addArrangedSubview(imageView);
imageView.image = UIImage(named: "imageview");
NSLayoutConstraint.activate([imageView.heightAnchor.constraint(equalToConstant:UIScreen.main.bounds.width / 2) ]);
imageView.contentMode = .scaleAspectFill;
imageView.clipsToBounds = true;
parentStackView.addArrangedSubview(label3)
label3.text = "Vertical Label below Image";
The result will look something like:
Set bottom and top anchor according to sequential view on top and bottom. Here, you are setting bottom anchor of both videolabel1 and videodate to bottom anchor which is wrong:-
set videoLabel trailing and top anchor and remove bottom anchor:-
videolabel1.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -20).isActive = true
videolabel1.topAnchor.constraint(equalTo: topAnchor, constant: 20).isActive = true
set videoLabel trailing anchor as below and remove bottom anchor:-
videodate.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -20).isActive = true
Also, remove bottom anchor of imagview and set bottom anchor constant as shown below:-
videotitle.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -12).isActive = true
I have a centered UITextField inside a UICollectionView Cell, but the text moves weirdly to the right when editing. What is causing the problem?
let textLabel: UITextField = {
let label = UITextField()
label.textAlignment = .center
label.adjustsFontSizeToFitWidth = true
label.minimumFontSize = 12
return label
}()
addSubview(textLabel)
textLabel.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 15).isActive = true
textLabel.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
textLabel.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
textLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -15).isActive = true
Here is a screen capture of the problem:
Update: Turns out the UITextfield's height is too large, I reduced its height and everything works perfectly now. Thanks for your kind help!
textLabel.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 15).isActive = true
textLabel.heightAnchor.constraint(equalToConstant: 50).isActive = true
textLabel.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
textLabel.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -15).isActive = true
I have this UIScrollView set up with a UIImageView and a UILabel.
However, it's not scrolling like I want it to. It's like it's not even there... How can I fix this? I just want it to be scrollable (even though theres nothing at the bottom to scroll to yet)
Thx in advance!
Here's my code:
// scrollView
scrollView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(scrollView)
// scrollView constraints
scrollView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
scrollView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
scrollView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
scrollView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
// Initialize profileImageView
profileImageView.image = #imageLiteral(resourceName: "neil")
profileImageView.translatesAutoresizingMaskIntoConstraints = false
profileImageView.layer.cornerRadius = 125 / 2
profileImageView.clipsToBounds = true
scrollView.addSubview(profileImageView)
// Add profileImageView constraints
profileImageView.topAnchor.constraint(equalTo: scrollView.topAnchor, constant: 45).isActive = true
profileImageView.heightAnchor.constraint(equalToConstant: 125).isActive = true
profileImageView.widthAnchor.constraint(equalToConstant: 125).isActive = true
profileImageView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
// Add separator view
seperator.translatesAutoresizingMaskIntoConstraints = false
seperator.backgroundColor = UIColor.darkGray
scrollView.addSubview(seperator)
// seperator constraints
seperator.heightAnchor.constraint(equalToConstant: 2).isActive = true
seperator.widthAnchor.constraint(equalTo: self.view.widthAnchor, multiplier: 0.8).isActive = true
seperator.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
seperator.topAnchor.constraint(equalTo: profileImageView.bottomAnchor, constant: 20).isActive = true
//nameLabel
let nameLabelFont = UIFont.monospacedDigitSystemFont(ofSize: 36, weight: UIFont.Weight.heavy)
nameLabel.font = nameLabelFont
nameLabel.text = currentUser.name
nameLabel.translatesAutoresizingMaskIntoConstraints = false
scrollView.addSubview(nameLabel)
// nameLabel constraints
nameLabel.topAnchor.constraint(equalTo: seperator.bottomAnchor, constant: 10).isActive = true
nameLabel.leadingAnchor.constraint(equalTo: seperator.leadingAnchor).isActive = true
You can't scroll because scrollView.contentSize isn't bigger then your view.
If you want make your screen scrollable you should set scrollView.contentSize.
Put scrollView.contentSize = CGSize(width: 1000, height: 1000) before view.addSubview(scrollView) to set your scrollable area to 1000x1000.
Generally scrollView.contentSize should be calculated base on UI elements inside UIScrollView e.g. size of 10 images with space between them.
I'm trying to make a simple layout that should scroll vertically when views are too many to fit on the screen.
So this is what I have so far:
I created a scrollview and a container view like that
let mainScrollView: UIScrollView = {
let scrollView = UIScrollView()
scrollView.isUserInteractionEnabled = true
scrollView.translatesAutoresizingMaskIntoConstraints = false
return scrollView
}()
let containerView: UIView = {
let view = UIView()
view.backgroundColor = .lightGray
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
Then I added the scrollview to the main view, added the container view to the scrollview and a couple of labels to the container view
view.addSubview(mainScrollView)
mainScrollView.addSubview(containerView)
containerView.addSubview(firstLabel)
containerView.addSubview(secondLabel)
I pinned the scrollview to the main view, and the container view to the scrollview. After that I started adding the labels inside the container view like this
mainScrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
mainScrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
mainScrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
mainScrollView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
containerView.topAnchor.constraint(equalTo: mainScrollView.layoutMarginsGuide.topAnchor).isActive = true
containerView.bottomAnchor.constraint(equalTo: mainScrollView.layoutMarginsGuide.bottomAnchor).isActive = true
containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
firstLabel.centerXAnchor.constraint(equalTo: containerView.centerXAnchor).isActive = true
firstLabel.topAnchor.constraint(equalTo: containerView.topAnchor, constant: 30).isActive = true
firstLabel.widthAnchor.constraint(equalToConstant: 50).isActive = true
firstLabel.heightAnchor.constraint(equalToConstant: 20).isActive = true
secondLabel.centerXAnchor.constraint(equalTo: containerView.centerXAnchor).isActive = true
secondLabel.topAnchor.constraint(equalTo: firstLabel.bottomAnchor, constant: 750).isActive = true
secondLabel.widthAnchor.constraint(equalToConstant: 50).isActive = true
secondLabel.heightAnchor.constraint(equalToConstant: 20).isActive = true
The problem is that for some reason the scrollview is not able to calculate it's height and it doesn't scroll vertically. The second label remains invisible because it's too "low" on the screen.
I tried setting the bottom constraint of the container view to the bottom of the second label but I'm going nowhere honestly.
What am I missing? How can I set constraints to make the scrollview scroll with autolayout (without setting a specific height of the container view)?
Scrollview scrolls in either direction. So any view added to it would need some additional constraints to let the Scrollview calculate its content size.
You have pinned the container view to scroll view. If you are looking at a vertically scrolling view like a table view then you need to also set the width of the scroll to the container view so that it can calculate the width.
Next for height, its automatically calculated based on the UI elements added in the container view. Ensure that all of the labels have leading, trailing to the container and vertical spacing to each other and top of the container view. This will let the scroll view know the height needed.
self.scrollView.translatesAutoresizingMaskIntoConstraints = false
self.contentView.translatesAutoresizingMaskIntoConstraints = false
self.label1.translatesAutoresizingMaskIntoConstraints = false
self.label2.translatesAutoresizingMaskIntoConstraints = false
self.label3.translatesAutoresizingMaskIntoConstraints = false
self.contentView.addSubview(self.label1)
self.contentView.addSubview(self.label2)
self.contentView.addSubview(self.label3)
self.scrollView.addSubview(self.contentView)
self.view.addSubview(self.scrollView)
NSLayoutConstraint.activate([
self.scrollView.topAnchor.constraint(equalTo: self.view.topAnchor),
self.scrollView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
self.scrollView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
self.scrollView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor)
])
NSLayoutConstraint.activate([
self.contentView.topAnchor.constraint(equalTo: self.scrollView.topAnchor),
self.contentView.trailingAnchor.constraint(equalTo: self.scrollView.trailingAnchor),
self.contentView.bottomAnchor.constraint(equalTo: self.scrollView.bottomAnchor),
self.contentView.leadingAnchor.constraint(equalTo: self.scrollView.leadingAnchor),
self.contentView.widthAnchor.constraint(equalTo: self.scrollView.widthAnchor)
])
NSLayoutConstraint.activate([
self.label1.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor),
self.label2.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor),
self.label3.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor),
self.label1.trailingAnchor.constraint(equalTo: self.contentView.trailingAnchor),
self.label2.trailingAnchor.constraint(equalTo: self.contentView.trailingAnchor),
self.label3.trailingAnchor.constraint(equalTo: self.contentView.trailingAnchor)
])
NSLayoutConstraint.activate([
self.label1.topAnchor.constraint(equalTo: self.contentView.topAnchor),
self.label2.topAnchor.constraint(equalTo: self.label1.bottomAnchor),
self.label3.topAnchor.constraint(equalTo: self.label2.bottomAnchor),
self.label3.bottomAnchor.constraint(equalTo: self.contentView.bottomAnchor)
])
And when run, it won't complain about any constraint issues either. Same can be done for horizontal scroll.
Thank you very much #GoodSp33d, you pointed me to the right direction.
I added the width constraint as you said like that:
containerView.widthAnchor.constraint(equalTo: mainScrollView.widthAnchor).isActive = true
And the key point was to update the bottom constraint after all:
containerView.bottomAnchor.constraint(equalTo: secondLabel.bottomAnchor).isActive = true
Here is the full working code:
mainScrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
mainScrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
mainScrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
mainScrollView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
containerView.topAnchor.constraint(equalTo: mainScrollView.topAnchor).isActive = true
containerView.trailingAnchor.constraint(equalTo: mainScrollView.trailingAnchor).isActive = true
containerView.bottomAnchor.constraint(equalTo: mainScrollView.bottomAnchor).isActive = true
containerView.leadingAnchor.constraint(equalTo: mainScrollView.leadingAnchor).isActive = true
containerView.widthAnchor.constraint(equalTo: mainScrollView.widthAnchor).isActive = true
firstLabel.centerXAnchor.constraint(equalTo: containerView.centerXAnchor).isActive = true
firstLabel.topAnchor.constraint(equalTo: containerView.topAnchor, constant: 30).isActive = true
firstLabel.widthAnchor.constraint(equalToConstant: 50).isActive = true
firstLabel.heightAnchor.constraint(equalToConstant: 20).isActive = true
secondLabel.centerXAnchor.constraint(equalTo: containerView.centerXAnchor).isActive = true
secondLabel.topAnchor.constraint(equalTo: firstLabel.bottomAnchor, constant: 550).isActive = true
secondLabel.widthAnchor.constraint(equalToConstant: 50).isActive = true
secondLabel.heightAnchor.constraint(equalToConstant: 20).isActive = true
containerView.bottomAnchor.constraint(equalTo: secondLabel.bottomAnchor).isActive = true
Thanks for the help.
I am trying to generate views displayed in a UIScrollView based on structured (XML) data at runtime. I generate all the views I need and add them to my scrollview afterwards, using Auto Layout to let the scrollview calculate its contentSize. Everything worked fine as long as I was only using UILabels and a custom UIImageView subclass, but now I want to add a nested view containing another view and a label to represent text with a vertical line on the left side.
The general layout code I'm using to add all generated views to the scrollview is as follows:
var previousAnchor = scrollView.topAnchor
views.forEach { (view) in
scrollView.addSubview(view)
view.translatesAutoresizingMaskIntoConstraints = false
view.topAnchor.constraint(equalTo: previousAnchor,
constant: UI.defaultPadding).isActive = true
view.leadingAnchor.constraint(equalTo: self.view.leadingAnchor,
constant: UI.smallPadding).isActive = true
view.trailingAnchor.constraint(equalTo: self.view.trailingAnchor,
constant: -UI.smallPadding).isActive = true
previousAnchor = view.bottomAnchor
}
scrollView.bottomAnchor.constraint(equalTo: previousAnchor,
constant: UI.defaultPadding).isActive = true
And the layout code for my nested subview looks like this (it's a UIView subclass):
addSubview(label)
addSubview(line)
line.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 10).isActive = true
line.topAnchor.constraint(equalTo: topAnchor).isActive = true
line.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
line.widthAnchor.constraint(equalToConstant: 2).isActive = true
line.trailingAnchor.constraint(equalTo: label.leadingAnchor).isActive = true
line.backgroundColor = UIColor.green
label.topAnchor.constraint(equalTo: topAnchor).isActive = true
label.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
label.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
label.numberOfLines = 0
label.text = "Here's to the crazy ones. The misfits. The rebels. The troublemakers."
If I use this code, I cannot see this view in my scrollview at all and the scrollview has a warning of ambiguous content size attached to it in the Debug View Hierarchy view. This is somewhat irritating, as using labels without being nested in a view like this does work like a charm. So I started playing around and what really puzzles me is that if I use the following code I can see the view itself (as I gave it a gray background color), but still can't see line and/or label, as both seem have a frame of (0,0,0,0) upon inspection:
addSubview(label)
addSubview(line)
line.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 10).isActive = true
line.topAnchor.constraint(equalTo: topAnchor, constant: 10).isActive = true
line.widthAnchor.constraint(equalToConstant: 20).isActive = true
line.heightAnchor.constraint(equalToConstant: 20).isActive = true
line.trailingAnchor.constraint(equalTo: label.leadingAnchor).isActive = true
line.backgroundColor = UIColor.green
label.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
label.trailingAnchor.constraint(equalTo: trailingAnchor).isActive = true
heightAnchor.constraint(equalToConstant: 100).isActive = true
heightAnchor.constraint(equalTo: label.heightAnchor).isActive = true
label.numberOfLines = 0
label.text = "Here's to the crazy ones. The misfits. The rebels. The troublemakers."
What am I missing? I also tried putting all my views into a container view instead of using them as subviews of the scrollview directly, but this did not help with my nested view and brought up other problems.