Comme d'iOS 10, Apple ne fournit pas un observateur NSNotification pour détecter le changement d'image lorsque le clavier est entraîné de manière interactive par UIScrollView, UIKeyboardWillChangeFrame et UIKeyboardDidChangeFrame sont observés une seule fois la libération du robinet.
Quoi qu'il en soit, après avoir regardé autour DAKeyboardControl bibliothèque, j'ai eu l'idée d'attacher UIScrollView.UIPanGestureRecognizer dans le UIViewController, donc des événements de mouvement qui sont produits seront traitées dans UIViewController aussi bien. Après avoir vissé plusieurs heures, je l'ai eu pour travailler, voici tout le code qui est nécessaire pour cela:
class ViewController: UIViewController, UIGestureRecognizerDelegate {
fileprivate let collectionView = UICollectionView(frame: .zero)
private let bottomView = UIView()
fileprivate var bottomInset: NSLayoutConstraint!
// This holds height of keypad
private var maxKeypadHeight: CGFloat = 0 {
didSet {
self.updateCollectionViewInsets(maxKeypadHeight + self.bottomView.frame.height)
self.bottomInset.constant = -maxKeypadHeight
}
}
private var isListeningKeypadChange = false
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(keypadWillChange(_:)), name: .UIKeyboardWillChangeFrame, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keypadWillShow(_:)), name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keypadWillHide(_:)), name: .UIKeyboardWillHide, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keypadDidHide), name: .UIKeyboardDidHide, object: nil)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
NotificationCenter.default.removeObserver(self)
}
func keypadWillShow(_ notification: Notification) {
guard !self.isListeningKeypadChange, let userInfo = notification.userInfo as? [String : Any],
let animationDuration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? TimeInterval,
let animationCurve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? UInt,
let value = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue
else {
return
}
self.maxKeypadHeight = value.cgRectValue.height
let options = UIViewAnimationOptions.beginFromCurrentState.union(UIViewAnimationOptions(rawValue: animationCurve))
UIView.animate(withDuration: animationDuration, delay: 0, options: options, animations: { [weak self] in
self?.view.layoutIfNeeded()
}, completion: { finished in
guard finished else { return }
// Some delay of about 500MS, before ready to listen other keypad events
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { [weak self] in
self?.beginListeningKeypadChange()
}
})
}
func handlePanGestureRecognizer(_ pan: UIPanGestureRecognizer) {
guard self.isListeningKeypadChange, let windowHeight = self.view.window?.frame.height else { return }
let barHeight = self.bottomView.frame.height
let keypadHeight = abs(self.bottomInset.constant)
let usedHeight = keypadHeight + barHeight
let dragY = windowHeight - pan.location(in: self.view.window).y
let newValue = min(dragY < usedHeight ? max(dragY, 0) : dragY, self.maxKeypadHeight)
print("Old: \(keypadHeight) New: \(newValue) Drag: \(dragY) Used: \(usedHeight)")
guard keypadHeight != newValue else { return }
self.updateCollectionViewInsets(newValue + barHeight)
self.bottomInset.constant = -newValue
}
func keypadWillChange(_ notification: Notification) {
if self.isListeningKeypadChange, let value = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {
self.maxKeypadHeight = value.cgRectValue.height
}
}
func keypadWillHide(_ notification: Notification) {
guard let userInfo = notification.userInfo as? [String : Any] else { return }
self.maxKeypadHeight = 0
var options = UIViewAnimationOptions.beginFromCurrentState
if let animationCurve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? UInt {
options = options.union(UIViewAnimationOptions(rawValue: animationCurve))
}
let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? TimeInterval
UIView.animate(withDuration: duration ?? 0, delay: 0, options: options, animations: {
self.view.layoutIfNeeded()
}, completion: nil)
}
func keypadDidHide() {
self.collectionView.panGestureRecognizer.removeTarget(self, action: nil)
self.isListeningKeypadChange = false
if (self.maxKeypadHeight != 0 || self.bottomInset.constant != 0) {
self.maxKeypadHeight = 0
}
}
private func beginListeningKeypadChange() {
self.isListeningKeypadChange = true
self.collectionView.panGestureRecognizer.addTarget(self, action: #selector(self.handlePanGestureRecognizer(_:)))
}
fileprivate func updateCollectionViewInsets(_ value: CGFloat) {
let insets = UIEdgeInsets(top: 0, left: 0, bottom: value + 8, right: 0)
self.collectionView.contentInset = insets
self.collectionView.scrollIndicatorInsets = insets
}
}
