Zoom on UIView contained in UIScrollView - ios

Question

I have some trouble handling zoom on UIScrollView that contains many subviews. I already saw many answers on SO, but none of them helped me.
So, basically what I'm doing is simple : I have a class called UIFreeView :
import UIKit
class UIFreeView: UIView, UIScrollViewDelegate {
var mainUIView: UIView!
var scrollView: UIScrollView!
var arrayOfView: [UIView]?
override init(frame: CGRect) {
super.init(frame: frame)
self.setupView()
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
fileprivate func setupView() {
// MainUiView
self.mainUIView = UIView(frame: self.frame)
self.addSubview(mainUIView)
// ScrollView
self.scrollView = UIScrollView(frame: self.frame)
self.scrollView.delegate = self
self.addSubview(self.scrollView)
}
func reloadViews(postArray:[Post]?) {
if let postArray = postArray {
print("UIFreeView::reloadVIew.postArraySize = \(postArray.count)")
let size: CGFloat = 80.0
let margin: CGFloat = 20.0
scrollView.contentSize.width = (size * CGFloat(postArray.count))+(margin*CGFloat(postArray.count))
scrollView.contentSize.height = (size * CGFloat(postArray.count))+(margin*CGFloat(postArray.count))
for item in postArray {
let view = buildPostView(item)
self.scrollView.addSubview(view)
}
}
}
fileprivate func buildPostView(_ item:Post) -> UIView {
// Const
let size: CGFloat = 80.0
let margin: CGFloat = 5.0
// Var
let view = UIView()
let textView = UITextView()
let backgroundImageView = UIImageView()
// Setup view
let x = CGFloat(UInt64.random(lower: UInt64(0), upper: UInt64(self.scrollView.contentSize.width)))
let y = CGFloat(UInt64.random(lower: UInt64(0), upper: UInt64(self.scrollView.contentSize.height)))
view.frame = CGRect(x: x,
y: y,
width: size,
height: size)
// Setup background view
backgroundImageView.frame = CGRect(x: 0,
y: 0,
width: view.frame.size.width,
height: view.frame.size.height)
var bgName = ""
if (item.isFromCurrentUser) {
bgName = "post-it-orange"
} else {
bgName = "post-it-white"
}
backgroundImageView.contentMode = .scaleAspectFit
backgroundImageView.image = UIImage(named: bgName)
view.addSubview(backgroundImageView)
// Setup text view
textView.frame = CGRect(x: margin,
y: margin,
width: view.frame.size.width - margin*2,
height: view.frame.size.height - margin*2)
textView.backgroundColor = UIColor.clear
textView.text = item.content
textView.isEditable = false
textView.isSelectable = false
textView.isUserInteractionEnabled = false
view.addSubview(textView)
let gestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePan))
view.addGestureRecognizer(gestureRecognizer)
return view
}
func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return self.scrollView
}
func handlePan(_ gestureRecognizer: UIPanGestureRecognizer) {
if gestureRecognizer.state == .began || gestureRecognizer.state == .changed {
let translation = gestureRecognizer.translation(in: self.scrollView)
// note: 'view' is optional and need to be unwrapped
gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation.x, y: gestureRecognizer.view!.center.y + translation.y)
gestureRecognizer.setTranslation(CGPoint.zero, in: self.scrollView)
}
}
/*
// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
// Drawing code
}
*/
}
This class is working perfectly, I can scroll through all my views, but I can't zoom-in and zoom-out in order to see less/more views on my screen.
I think the solution is simple, but I can't seem to find a real solution for my problem ..
Thanks !