I'm experiencing bugs with my application when I'm trying to download and set an image async to a cell with dynamic height.
Video of the bug: https://youtu.be/nyfjCmc0_Yk
I'm clueless: can't understand why it happens. I'm saving the cell heights for preventing jumping issues and stuff, I do even update the height of the cell after setting the image.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var post : Post
var cell : PostCell
post = Posts.shared.post(indexPath: indexPath)
// I REMOVED SOME NOT IMPORTANT PARTS OF THE CODE
// (like setting the text, etc)
if post.images.count > 0 {
// Images is attached to the post
cell.postImageView.sd_setImage(with: URL(string: appSettings.url + "/resources/img/posts/" + post.images[0]), placeholderImage: nil, options: [.avoidAutoSetImage]) { (image, error, type, url) in
if let error = error {
// placeholder
return
}
DispatchQueue.main.async {
let cgRect = image!.contentClippingRect(maxWidth: 300, maxHeight: 400)
cell.postImageView.isHidden = false
cell.postImageWidthConstraint.constant = cgRect.width
cell.postImageViewHeightConstraint.constant = cgRect.height
cell.postImageView.image = image
cell.layoutIfNeeded()
self.cellHeights[indexPath] = cell.frame.size.height
}
}
} else {
// No image is attached to the post
cell.postImageViewHeightConstraint.constant = 0
cell.postImageWidthConstraint.constant = 0
cell.postImageView.isHidden = true
}
return cell
}
var cellHeights: [IndexPath : CGFloat] = [:]
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
cellHeights[indexPath] = cell.frame.size.height
cell.layoutIfNeeded()
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
if cellHeights[indexPath] != nil {
return CGFloat(Float(cellHeights[indexPath] ?? 0.0))
}
else {
return UITableViewAutomaticDimension
}
}
I've tried calling tableView.beginUpdates() tableView.endUpdates(), it fixes the problem at the beginning, but when scrolling it creates a weird bug :
(random appearing small part of the image in the tableview)
And when scrolling up, it jumps to the beginning of the post.. maybe due to the incorrect height value?
What do I do wrong?
