How do I animate a collectionView without the cells moving? - ios

Question

I am trying to create a collectionView which slides up when the user swipes up. For now I am using a button instead of the scroll gesture to trigger the animation. When the animation Begins I want the collectionView to expand in height but the cells to stay where they are and then as the user scrolls slide up. How do I animate the collectionView without moving the cells? Is this possible to do? I would like for the collectionView to expand up and show the hidden cells that were covered up during the scroll not or show a blank space from the collectionView not just move all of the cells higher on the screen.
Function of Code in Question
var buttonPressed:Bool = true
#IBAction func changeView(_ sender: Any) {
if buttonPressed{
UIView.animate(withDuration: 0.05){
self.animateCollectionView.frame = CGRect(x: 0, y: 100, width: 600, height: 1000)
// self.animateCollectionView.transform = CGAffineTransform(translationX: 0, y: -20)
self.view.sendSubview(toBack: self.animateCollectionView)
self.buttonPressed = !self.buttonPressed
print("Ive been expanded")
}
}
else{
UIView.animate(withDuration: 0.05){
self.animateCollectionView.frame = CGRect(x: 0, y: 20, width: 600, height: 1000)
// self.animateCollectionView.transform = CGAffineTransform(translationX: 0, y: 20)
self.buttonPressed = !self.buttonPressed
}
}
}
Code as whole:
import UIKit
class ViewController: UIViewController,UICollectionViewDataSource,UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 200
}
var counter:Int = 0
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = self.animateCollectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! customCell
counter+=1
cell.cellLabel.text = "\(counter)"
cell.backgroundColor = UIColor.orange
return cell
}
#IBOutlet weak var animateCollectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
animateCollectionView.dataSource = self
animateCollectionView.delegate = self
animateCollectionView.backgroundColor = UIColor.blue
animateCollectionView.frame = CGRect(x: 0, y: 100, width: 600, height: 1000)
self.view.sendSubview(toBack: self.animateCollectionView)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
var buttonPressed:Bool = true
#IBAction func changeView(_ sender: Any) {
if buttonPressed{
UIView.animate(withDuration: 0.05){
self.animateCollectionView.frame = CGRect(x: 0, y: 100, width: 600, height: 1000)
// self.animateCollectionView.transform = CGAffineTransform(translationX: 0, y: -20)
self.view.sendSubview(toBack: self.animateCollectionView)
self.buttonPressed = !self.buttonPressed
print("Ive been expanded")
}
}
else{
UIView.animate(withDuration: 0.05){
self.animateCollectionView.frame = CGRect(x: 0, y: 20, width: 600, height: 1000)
// self.animateCollectionView.transform = CGAffineTransform(translationX: 0, y: 20)
self.buttonPressed = !self.buttonPressed
}
}
}
}
class customCell :UICollectionViewCell{
#IBOutlet weak var cellLabel: UILabel!
}