Why does this logic work well (UICollectionViewCell + CustomPaddingLabel) - swift

Question

When I make a message UI, need a dynamic height UICollectionViewCell which be calculated with label's height. But first try the cell when reuse, customLabel's layout did not change so the cell is maintained cell's layout which previously used.
I found that the problem is CustomPaddingLabel and make it working well. But I still can't understand why this logic make working well. Read layout life cylcle, UICollectionView life cycle, but that can't solve this question.
plz, explain why this logic can make working well, also why CustomPaddingLabel cause this problem. (When I try with UILabel, this problem does not occured)
This is UICollectionViewCell...
final class MessageCell: UICollectionViewCell {
static let identifier: String = .init(describing: MessageCell.self)
private let messageLabel: PaddingLabel = .init().then {
$0.numberOfLines = 0
$0.textColor = .black
$0.font = .systemFont(ofSize: 14.5)
$0.lineBreakStrategy = .pushOut
$0.layer.cornerRadius = 14
$0.clipsToBounds = true
$0.setContentHuggingPriority(.defaultLow, for: .horizontal)
$0.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
}
private let dateLabel = UILabel().then {
$0.font = .systemFont(ofSize: 10, weight: .regular)
$0.textColor = .secondaryLabel
$0.numberOfLines = 1
}
private var chatType: ChatType = .none
override init(frame: CGRect) {
super.init(frame: frame)
self.addSubviews(messageLabel, dateLabel)
}
#available(*, unavailable)
required init?(coder: NSCoder) {
fatalError("Does not use this initializer")
}
override func layoutSubviews() {
super.layoutSubviews()
}
override func prepareForReuse() {
super.prepareForReuse()
messageLabel.text = nil
dateLabel.text = nil
chatType = .none
self.messageLabel.snp.removeConstraints()
self.dateLabel.snp.removeConstraints()
self.messageLabel.layoutIfNeeded()
}
func setCell(with message: String, type: ChatType, dateString: String) {
self.messageLabel.text = message
self.chatType = type
self.dateLabel.text = dateString
self.configureLayouts()
self.configureProperties()
}
}
private extension MessageCell {
func configureLayouts() {
switch chatType {
case .none:
break
case .send:
messageLabel.snp.remakeConstraints { make in
make.top.bottom.equalToSuperview()
make.trailing.equalToSuperview().inset(20)
make.leading.greaterThanOrEqualToSuperview()
}
dateLabel.snp.remakeConstraints { make in
make.trailing.equalTo(messageLabel.snp.leading).offset(-4)
make.leading.greaterThanOrEqualToSuperview().inset(56)
make.bottom.equalTo(messageLabel)
}
case .receive:
messageLabel.snp.remakeConstraints { make in
make.top.bottom.equalToSuperview()
make.leading.equalToSuperview().inset(56)
make.trailing.lessThanOrEqualToSuperview()
}
dateLabel.snp.remakeConstraints { make in
make.leading.equalTo(messageLabel.snp.trailing).offset(4)
make.trailing.lessThanOrEqualToSuperview().inset(24)
make.bottom.equalTo(messageLabel)
}
}
}
func configureProperties() {
switch chatType {
case .none:
break
case .send:
messageLabel.backgroundColor = UIColor(red: 250/255, green: 230/255, blue: 76/255, alpha: 1)
case .receive:
messageLabel.backgroundColor = .white
}
}
}
and this is CustomPaddingLabel...
class PaddingLabel: UILabel {
private var topInset: CGFloat
private var bottomInset: CGFloat
private var leftInset: CGFloat
private var rightInset: CGFloat
override var intrinsicContentSize: CGSize {
let size = super.intrinsicContentSize
return CGSize(width: size.width + leftInset + rightInset, height: size.height + topInset + bottomInset)
}
override var bounds: CGRect {
didSet {
preferredMaxLayoutWidth = bounds.width - (leftInset + rightInset)
}
}
init(topInset: CGFloat = 8, bottomInset: CGFloat = 8, leftInset: CGFloat = 10, rightInset: CGFloat = 10) {
self.topInset = topInset
self.bottomInset = bottomInset
self.leftInset = leftInset
self.rightInset = rightInset
super.init(frame: .zero)
}
#available(*, unavailable)
required init?(coder: NSCoder) {
fatalError("Does not use this initializer")
}
override func drawText(in rect: CGRect) {
let insets = UIEdgeInsets(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
super.drawText(in: rect.inset(by: insets))
}
}
Configure the cell height of the UICollectionVIew to dynamic according to the CustomPaddingLabel's height. But when the cell be reused, CustomPaddingLabel's layout is concreted so the next cell has unbalance fit layout.
I found the problem is from CustomPaddingLabel (use UILabel this problem doesn't happen), and fix it worked well. But I don't know why this problem was occured and why this logic solved that problem.
plz, explain this question.