CODEWITHSUNDEEP
iosuitableviewuicollectionview
etayluz
etayluz

Reputation: 16426

UICollectionView inside UITableViewCell does NOT dynamically size correctly

I have a UICollectionView inside a UITableViewCell.

I am setting the UITableViewCell row height to be dynamic:

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
   return UITableViewAutomaticDimension
}

My UICollectionView has a variable number of items:

func collectionView(_ collectionView: UICollectionView,
                    numberOfItemsInSection section: Int) -> Int {
    return items.count
}

Now here is the sequence of events that is causing me headache:

I have found an ugly work around by reloading the UITableView but I don't like this approach at all:

private func reloadCell() {
    let when = DispatchTime.now()
    DispatchQueue.main.asyncAfter(deadline: when) {
        if let indexPath = self.chatViewController?.chatTableView.indexPath(for: self) {
            self.tableView.reloadRows(at: [indexPath], with: .none)
        }
    }
}

My question is if I can force the UICollectionView to reload and call it's delegates immediately so that the UITableViewCell height can be computed by the autolayout engine correctly?

Upvotes: 1

Views: 467

Answers (1)

Kirti Parghi
Kirti Parghi

Reputation: 1152

In viewDidLoad, add observer for collection view,

 collectionView.addObserver(self, forKeyPath: "contentSize", options: NSKeyValueObservingOptions.Old.union(NSKeyValueObservingOptions.New), context: self)

Now, overrider observe value for keypath for controlling collection view reload completion handler through KVO.

 override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) 
 {
    // You will get here when the reloadData finished 
 }

Now, in view Will Disappear remove observer that was set for collection view.

 override func viewWillDisappear(_ animated: Bool) {
 {
   // remove collection view observer   
 }

Same logic will be applied for tableview in order to get fully visible tableview cell containing collection view inside it.

Upvotes: 0

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