UIStackView, Autolayout, Table Cells - swift

Question

I'm creating a UIStackView with an image and a label in a custom UIControl that will be in a custom UITableViewCell, except that my UIStackView has a height & width of 0 and XCode is complaining about breaking constraints. Only if I explicitly set a height and width does it show properly, which I don't want because the label text varies from cell to cell. (This is all happening programmatically.)
The Setup
In my UITableViewCell, I've got the following:
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
contentView.addSubview(control)
NSLayoutConstraint.activate([
control.bottomAnchor.constraint(equalTo: contentView.bottomAnchor),
control.leadingAnchor.constraint(equalTo: contentView.leadingAnchor),
control.trailingAnchor.constraint(equalTo: contentView.trailingAnchor),
control.topAnchor.constraint(equalTo: contentView.topAnchor),
])
}
// empty coder init as well
private let control: MyControl = {
let control: MyControl = MyControl()
control.translatesAutoresizingMaskIntoConstraints = false
return control
}()
In MyControl, I just have the UIStackView, a UIImageView, and a UILabel. To not bore you with code...only the UIStackView (horizontal axis) is using constraints, pinning it to the four sides. The UIImageView (initiated with an image) is one arranged subview, the UILabel is the other (initiated with default text).
If you want to see the code:
class MyControl: UIControl {
override init(frame: CGRect) {
super.init(frame: frame)
addSubview(stackView)
stackView.addArrangedSubview(icon)
stackView.addArrangedSubview(contentLabel)
NSLayoutConstraint.activate([
stackView.bottomAnchor.constraint(equalTo: bottomAnchor),
stackView.leadingAnchor.constraint(equalTo: leadingAnchor),
stackView.trailingAnchor.constraint(equalTo: trailingAnchor),
stackView.topAnchor.constraint(equalTo: topAnchor),
])
}
// empty coder init as well
private let contentLabel: UILabel = {
let label: UILabel = UILabel()
label.text = "Initial text"
return label
}()
private let icon: UIImageView = {
let iv: UIImageView = UIImageView(image: UIImage(named: "placeholder_image")!)
iv.contentMode = .scaleAspectFit
return iv
}()
private let stackView: UIStackView = {
let stackView: UIStackView = UIStackView()
stackView.axis = .horizontal
stackView.translatesAutoresizingMaskIntoConstraints = false
return control
}()
}
What I'm Expecting
I'm expecting the UIControl to be the height of the image (because it's taller than the label text), and the width of the image + the label text. (And then display full table cell width because of that constraint pinning). And because these are set on initialization of these components, I'd expect them to have an intrinsic height and width to pass to the UIStackView.
What I'm Getting
A height and width of zero, and XCode complaints of broken constraints. If I remove all constraints, I get no complaints but nothing appears (as if the height & width are zero but XCode doesn't care because I didn't set any constraints).
What I've Tried
Literally every combination of layout constraints, including none on everything and as many as I can on everything. What I'd like is for the image + label text to set the height and width of the UIStackView which would then set the height and width of the UIControl, which would then set the height in the UITableViewCell (I know I have width 100% - that will change later).
Other Considerations
There's nothing else special about my UITableViewCell that would cause any issue here except that in my actual code, I have a multi-line label above MyControl which should (and does) cause my UITableViewCell to expand in height.

Answer 1

The problem with your question is that so much of the code you've shown is bogus that it's hard to guess what you might actually be doing. You claim that in your table view cell (I presume it's a table view cell subclass) you are saying
override init(frame: CGRect) {
super.init(frame: frame)
But that would never compile, as init(frame:) is not the designated initializer for a UITableViewCell. You have code like this:
private let contentLabel: UILabel = {
let label: UILabel = UILabel()
label.text = "Initial text"
return label
}
But that would never compile, as a function is not a label.
If we make allowances for all of that and fix your code, it's difficult to see what you would be doing wrong. I corrected your code so that it would compile, and I got this in my table view:
That might not be exactly what you were after, but the image view is certainly sizing the cells to its own height.
What you are doing is not at all how one makes and configures a table view cell (you should be doing the work in cellForRowAt, not hard coding the cell's image view and label contents in the cell's initializer), but given what you've shown, the image view does size the stack view which does size the cell (contrary to my own initial expectations).
Another issue is that you can't put an image view and a label into an autolayout situation without resolving the ambiguity as to which should predominate. I added this line to do that:
iv.setContentHuggingPriority(.defaultLow+1, for: .horizontal)