How to expand an xib collectionviewcell height dynamically? - swift

Question

I am looking to make my xib custom collection view cell height dynamic when clicked upon rather than using a fixed variable height.
I have tried using constraints on the heights of the cell in the storyboard.
This is the MotCollectionViewCell.swift code:
import UIKit
protocol ExpandedCellDelegate:NSObjectProtocol{
func topButtonTouched(indexPath:IndexPath)
}
class MotCollectionViewCell: UICollectionViewCell {
#IBOutlet var heightConstraint: NSLayoutConstraint!
#IBOutlet var topButton: UIButton!
weak var delegate:ExpandedCellDelegate?
public var indexPath:IndexPath!
#IBAction func topButtonTouched(_ sender: UIButton) {
if let delegate = self.delegate{
delegate.topButtonTouched(indexPath: indexPath)
}
}
#IBOutlet var testLbl: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
}
This is the BarChartViewControllerCell.Swift code :
import UIKit
import Charts
class BarChartViewController: UIViewController, ChartViewDelegate, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout, ExpandedCellDelegate {
// Bar Chart Properties
#IBOutlet var barChartView: BarChartView!
var dataEntry: [BarChartDataEntry] = []
// Chart Data
var result = [String]()
var mileage = [String]()
var colours = [UIColor]()
var list = [Tester]()
// Collection View properties
#IBOutlet var collectionView: UICollectionView!
var expandedCellIdentifier = "MotCollectionViewCell"
var cellWidth:CGFloat{
return collectionView.frame.size.width
}
var expandedHeight : CGFloat = 258
var notExpandedHeight : CGFloat = 75
var dataSource = ["data0","data1","data2","data3","data4"]
var isExpanded = [Bool]()
override func viewDidLoad() {
super.viewDidLoad()
isExpanded = Array(repeating: false, count: dataSource.count)
//Register nib cell
let nibCell = UINib(nibName: expandedCellIdentifier, bundle: nil)
collectionView.register(nibCell, forCellWithReuseIdentifier: expandedCellIdentifier)
}
// Collection View functions
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return dataSource.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: expandedCellIdentifier, for: indexPath) as! MotCollectionViewCell
cell.indexPath = indexPath
cell.delegate = self
//configure Cell
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
if isExpanded[indexPath.row] == true{
return CGSize(width: cellWidth, height: expandedHeight)
}else{
return CGSize(width: cellWidth, height: notExpandedHeight)
}
}
func topButtonTouched(indexPath: IndexPath) {
isExpanded[indexPath.row] = !isExpanded[indexPath.row]
UIView.animate(withDuration: 0.8, delay: 0.0, usingSpringWithDamping: 0.9, initialSpringVelocity: 0.9, options: UIView.AnimationOptions.curveEaseInOut, animations: {
self.collectionView.reloadItems(at: [indexPath])
}, completion: { success in
print("success")
})
}
}
When the cell is clicked, the cell expands to the height which I declared as a constant, what I am trying to achieve is have the cell expand according to the data within it.