Programmatically set constraints for uitableviewcell with uilabel and uiimageview - ios

Question

I am trying to build my tableview with custom UITableViewCell but facing some issues in coinstraints. Following is my custom UITablviewCell class:
class MovieCell: UITableViewCell {
static let identifier = "MovieCell"
let cellMargin = 15.0
private lazy var containerView: UIView = {
let view = UIView()
view.backgroundColor = .lightGray
view.layer.cornerRadius = 5
view.translatesAutoresizingMaskIntoConstraints = false
view.clipsToBounds = true
return view
}()
private let movieNameLabel: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
label.font = UIFont.movieAppBoldFont(size: 15)
label.numberOfLines = 0
return label
}()
private let movieImageView: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.contentMode = .scaleAspectFill
imageView.clipsToBounds = true
return imageView
}()
var movieCellViewModel : MoviewCellViewModel = MoviewCellViewModel(image: nil, name: "") {
didSet {
movieNameLabel.text = movieCellViewModel.name
}
}
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
backgroundColor = UIColor(red: 1, green: 1, blue: 1, alpha: 0)
layoutSubView()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
private func layoutSubView() {
addSubview(containerView)
containerView.addSubview(movieNameLabel)
containerView.addSubview(movieImageView)
let marginGuide = containerView.layoutMarginsGuide
NSLayoutConstraint.activate([
containerView.topAnchor.constraint(equalTo: contentView.layoutMarginsGuide.topAnchor),
containerView.leadingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.leadingAnchor),
containerView.trailingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.trailingAnchor),
containerView.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor, constant: -cellMargin),
movieImageView.leadingAnchor.constraint(equalTo: marginGuide.leadingAnchor, constant: 5),
movieImageView.topAnchor.constraint(equalTo: marginGuide.topAnchor, constant: 5),
movieImageView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -5),
movieImageView.widthAnchor.constraint(equalToConstant: 50),
movieImageView.heightAnchor.constraint(equalToConstant: 50),
movieNameLabel.leadingAnchor.constraint(equalTo: marginGuide.trailingAnchor, constant: 5),
movieNameLabel.trailingAnchor.constraint(equalTo: marginGuide.trailingAnchor, constant: -5),
movieNameLabel.topAnchor.constraint(equalTo: marginGuide.topAnchor, constant: 5),
movieNameLabel.bottomAnchor.constraint(equalTo: marginGuide.bottomAnchor, constant: -5)
])
}
}
I get the following result with the above code:
I am trying to create a UIView and add content to it. I am adding it because I want to show some empty space as a separator in tableview.

Answer 1

Couple issues...
Your first line in layoutSubView() is:
addSubview(containerView)
where is needs to be:
contentView.addSubview(containerView)
Second, you have movieImageView constrained to contentView:
movieImageView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -5),
where it should be constrained to marginGuide:
movieImageView.bottomAnchor.constraint(equalTo: marginGuide.bottomAnchor, constant: -5),
Third, you have movieNameLabel.leadingAnchor constrained to marginGuide.trailingAnchor:
movieNameLabel.leadingAnchor.constraint(equalTo: marginGuide.trailingAnchor, constant: 5),
where it should be constrained to movieImageView.trailingAnchor:
movieNameLabel.leadingAnchor.constraint(equalTo: movieImageView.trailingAnchor, constant: 5),
Making those changes will give you this (I set image view background to blue, and label background to cyan):
However, when you run the app, you'll see lots of Unable to simultaneously satisfy constraints. messages. This is common when using subviews with subviews in cells.
To get rid of the auto-layout complaints, we can give the containerView bottom anchor a less-than-required priority:
let bottomC = containerView.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor, constant: -cellMargin)
bottomC.priority = .required - 1
and then activate that in your constraints block:
//containerView.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor, constant: -cellMargin),
bottomC,
Here's your complete MovieCell class with those changes:
class MovieCell: UITableViewCell {
static let identifier = "MovieCell"
let cellMargin = 15.0
private lazy var containerView: UIView = {
let view = UIView()
view.backgroundColor = .lightGray
view.layer.cornerRadius = 5
view.translatesAutoresizingMaskIntoConstraints = false
view.clipsToBounds = true
return view
}()
private let movieNameLabel: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
label.font = .systemFont(ofSize: 15, weight: .bold) // UIFont.movieAppBoldFont(size: 15)
label.numberOfLines = 0
return label
}()
private let movieImageView: UIImageView = {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.contentMode = .scaleAspectFill
imageView.clipsToBounds = true
return imageView
}()
var movieCellViewModel : MoviewCellViewModel = MoviewCellViewModel(image: nil, name: "") {
didSet {
movieNameLabel.text = movieCellViewModel.name
}
}
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
backgroundColor = UIColor(red: 1, green: 1, blue: 1, alpha: 0)
layoutSubView()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
private func layoutSubView() {
contentView.addSubview(containerView)
containerView.addSubview(movieNameLabel)
containerView.addSubview(movieImageView)
let marginGuide = containerView.layoutMarginsGuide
let bottomC = containerView.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor, constant: -cellMargin)
bottomC.priority = .required - 1
NSLayoutConstraint.activate([
containerView.topAnchor.constraint(equalTo: contentView.layoutMarginsGuide.topAnchor),
containerView.leadingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.leadingAnchor),
containerView.trailingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.trailingAnchor),
// containerView.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor, constant: -cellMargin),
bottomC,
movieImageView.leadingAnchor.constraint(equalTo: marginGuide.leadingAnchor, constant: 5),
movieImageView.topAnchor.constraint(equalTo: marginGuide.topAnchor, constant: 5),
// movieImageView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -5),
movieImageView.bottomAnchor.constraint(equalTo: marginGuide.bottomAnchor, constant: -5),
movieImageView.widthAnchor.constraint(equalToConstant: 50),
movieImageView.heightAnchor.constraint(equalToConstant: 50),
// movieNameLabel.leadingAnchor.constraint(equalTo: marginGuide.trailingAnchor, constant: 5),
movieNameLabel.leadingAnchor.constraint(equalTo: movieImageView.trailingAnchor, constant: 5),
movieNameLabel.trailingAnchor.constraint(equalTo: marginGuide.trailingAnchor, constant: -5),
movieNameLabel.topAnchor.constraint(equalTo: marginGuide.topAnchor, constant: 5),
movieNameLabel.bottomAnchor.constraint(equalTo: marginGuide.bottomAnchor, constant: -5)
])
// during dev, so we can easily see the frames
movieImageView.backgroundColor = .systemBlue
movieNameLabel.backgroundColor = .cyan
}
}