Stackview inside collectionview or uitableview - ios

Question

I am trying to achieve a layout of a text followed by an image (image height calculated based on aspect ratio) then followed by text and so on. The issue is that the stackview that I am adding the views into randomly squash the views sometimes the imageviews disappear some time the text, it doesn't have a consistent behaviour.
i tried it on both uitableview and uicolletion view and the result is the same. is the combination of the mentioned views considered as a best practice for such usecase or not ? and if not what might be the best practice for such thing ?
class MyStackyView: UIStackView {
// Main variables
weak var videoPlayerDelegate: AVPlayerViewDelegate?
private var avVideoPlayersVC: [AVPlayerViewController] = []
var content: [Content]! {
didSet {
contentCombined = Utility.shared.combineToNew(contents: content)
}
}
private var contentCombined: [Content] = [] {
didSet {
populatePostContent()
}
}
var contentViews: [UIView] = [] // Holds the views created
override init(frame: CGRect) {
super.init(frame: frame)
configureView()
}
required init(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
deinit {
print("DiaryPostView:: Deinitalized")
}
private func configureView() {
axis = .vertical
distribution = .fill
alignment = .fill
spacing = 0
}
}
// Extension to populate post content
extension MyStackyView {
private func populatePostContent() {
for content in contentCombined {
if content.isMedia {
addMedia(content)
} else {
addText(content.text)
}
}
}
}
// Extension to add the required views
extension MyStackyView {
private func addText(_ text: String?, place: MediaPlace = .center) {
let textView = generateDefaultTextView()
//let parsedText = HTMLParser.shared.parseHTMLToAttributed(string: text ?? "") // fix font issue
switch place {
case .center:
append(textView)
contentViews.append(textView)
}
textView.text = text
// لما استخدم ال parsedtext مرة النص بطلع مع الfont و مرة لا
}
private func addMedia(_ content: Content) {
let avPlayerVC = getAVPlayerViewController()
let mediaView = generateDefaultMediaView()
switch content.getRawPlace() {
case .center:
append(mediaView)
contentViews.append(mediaView)
addText(content.text)
NetworkManager().downloadMedia(content.img!, into: mediaView, avPlayerViewController: avPlayerVC) {
}
}
}
}
extension MyStackyView {
private func generateDefaultTextView() -> UILabel {
let textView = UILabel()
textView.backgroundColor = .clear
textView.numberOfLines = 0
textView.font = UIFont.customFont(.openSans, .regular, .title1, 17)
return textView
}
private func generateDefaultHorizontalStack() -> UIStackView {
let horizontalStack = UIStackView()
horizontalStack.axis = .horizontal
horizontalStack.distribution = .fill
horizontalStack.alignment = .fill
return horizontalStack
}
private func generateDefaultMediaView() -> MediaSliderView {
let mediaSliderView = MediaSliderView()
return mediaSliderView
}
private func getAVPlayerViewController() -> AVPlayerViewController? {
videoPlayerDelegate?.getAVPlayerVC?()
}
func deallocateAVPlayers() {
for player in avVideoPlayersVC {
player.removeFromParent()
}
avVideoPlayersVC.removeAll()
}
}
i initalize a variable of the class in my uitableviewcell and then add these constraints
contentView.addSubview(MyStackyView)
MyStackyView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 8).isActive = true
MyStackyView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -8).isActive = true
MyStackyView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 16).isActive = true
MyStackyView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -16).isActive = true
please if possible, i need some guidance about this issue.
thank you, appreciate the help

Answer 1

Here is a (fairly) basic example.
We'll use a data structure like this:
struct VarDevStruct {
var first: String = ""
var second: String = ""
var imageName: String = ""
}
The cell class has a vertical stack view containing:
multiline label
horizontal stack view
with an 80x80 image view and a label
multiline label
If any of the elements in the data struct are empty strings, we'll set the corresponding element in the cell to hidden.
First, the result:
after scrolling down to a few rows with different data:
and rotated:
Here's the complete code... plenty of comments in it, so it should be clear what the code is doing.
Data Structure
struct VarDevStruct {
var first: String = ""
var second: String = ""
var imageName: String = ""
}
Cell class
class VarDevCell: UITableViewCell {
let firstLabel = UILabel()
let secondLabel = UILabel()
let imgView = UIImageView()
let imgNameLabel = UILabel()
let vStack = UIStackView()
let hStack = UIStackView()
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
commonInit()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
commonInit()
}
func commonInit() -> Void {
// stack view properties
vStack.axis = .vertical
vStack.alignment = .fill
vStack.distribution = .fill
vStack.spacing = 8
vStack.translatesAutoresizingMaskIntoConstraints = false
contentView.addSubview(vStack)
// let's use the default cell margins
let g = contentView.layoutMarginsGuide
NSLayoutConstraint.activate([
// constrain stack view to all 4 sides
vStack.topAnchor.constraint(equalTo: g.topAnchor),
vStack.leadingAnchor.constraint(equalTo: g.leadingAnchor),
vStack.trailingAnchor.constraint(equalTo: g.trailingAnchor),
vStack.bottomAnchor.constraint(equalTo: g.bottomAnchor),
])
// subview properties
// background colors to make it easy to see the frames
firstLabel.backgroundColor = .yellow
secondLabel.backgroundColor = .green
imgView.backgroundColor = .red
imgNameLabel.backgroundColor = .cyan
// multi-line labels
firstLabel.numberOfLines = 0
secondLabel.numberOfLines = 0
imgNameLabel.textAlignment = .center
// image view defaults to scaleToFill
// let's set it to scaleAspectFit
imgView.contentMode = .scaleAspectFit
// horizontal stack view
hStack.axis = .horizontal
hStack.alignment = .center
hStack.distribution = .fill
hStack.spacing = 8
// add subviews to horizontal stack view
hStack.addArrangedSubview(imgView)
hStack.addArrangedSubview(imgNameLabel)
// let's fill the vertical stack view with
// label
// hStack with 80x80 imageview and label with image name
// label
vStack.addArrangedSubview(firstLabel)
vStack.addArrangedSubview(hStack)
vStack.addArrangedSubview(secondLabel)
// set image view width and height
imgView.widthAnchor.constraint(equalToConstant: 80.0).isActive = true
imgView.heightAnchor.constraint(equalTo: imgView.widthAnchor, multiplier: 1.0).isActive = true
}
func fillData(_ vdStruct: VarDevStruct) -> Void {
firstLabel.text = vdStruct.first
secondLabel.text = vdStruct.second
imgNameLabel.text = vdStruct.imageName
// does our data have an image name?
if !vdStruct.imageName.isEmpty {
if #available(iOS 13.0, *) {
if let img = UIImage(systemName: vdStruct.imageName) {
imgView.image = img
}
} else {
// Fallback on earlier versions
if let img = UIImage(named: vdStruct.imageName) {
imgView.image = img
}
}
}
// hide elements that we don't need in this cell
firstLabel.isHidden = vdStruct.first.isEmpty
secondLabel.isHidden = vdStruct.second.isEmpty
hStack.isHidden = vdStruct.imageName.isEmpty
}
}
Controller class
class VarDevTableViewController: UITableViewController {
var myData: [VarDevStruct] = []
override func viewDidLoad() {
super.viewDidLoad()
// register cell class for reuse
tableView.register(VarDevCell.self, forCellReuseIdentifier: "cell")
// generate some sample data
myData = makeSampleData()
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
coordinator.animate(alongsideTransition: nil, completion: {
_ in
// make sure table re-calculates row heights
UIView.setAnimationsEnabled(false)
self.tableView.performBatchUpdates(nil, completion: nil)
UIView.setAnimationsEnabled(true)
})
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return myData.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! VarDevCell
cell.fillData(myData[indexPath.row])
return cell
}
func makeSampleData() -> [VarDevStruct] {
var a: [VarDevStruct] = []
// 15 sample data elements
for i in 1...15 {
let d = VarDevStruct(first: "This is the text for the first label in row: \(i).",
second: "This will be a longer string to be used as the text for the second label in row \(i) (long enough to make sure we're getting some word wrapping).",
imageName: "\(i).square.fill")
a.append(d)
}
// change some of the sample data for variations
// (arrays are zero-based)
// fifth row: no first label
a[4].first = ""
a[4].second = "This row has no First label text."
// sixth row: no image
a[5].first = "This row has no image."
a[5].imageName = ""
// seventh row: no second label
a[6].first = "This row has no second label."
a[6].second = ""
// eigth row: no image or second label
a[7].first = "This row has no image, and has no second label. The next row (9) has image only."
a[7].imageName = ""
a[7].second = ""
// ninth row: image only
a[8].first = ""
a[8].second = ""
// tenth row: first label with mutliple lines
a[9].first = "One\nTwo\nThree\nFour"
a[9].second = "This row has embedded newline chars in the text of the first label."
return a
}
}