Swift give uicollectionviewcell width and dynamic height - ios

Question

I have this uicollectionviewcell
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = commentSection.dequeueReusableCell(withReuseIdentifier: cellId, for: indexPath) as! CommentCell
return cell
}
CommentCell:
let CommenterprofileImage: UIImageView = {
let v = UIImageView()
v.translatesAutoresizingMaskIntoConstraints = false
return v
}()
let commentText: UILabel = {
let l = UILabel()
l.numberOfLines = 0
l.text = "some text"
l.translatesAutoresizingMaskIntoConstraints = false
return l
}()
override init(frame: CGRect) {
super.init(frame: frame)
backgroundColor = .blue
designCell()
}
func designCell(){
addSubview(CommenterprofileImage)
addSubview(commentText)
addCellConstraints()
}
func addCellConstraints(){
CommenterprofileImage.topAnchor.constraint(equalTo: self.topAnchor,constant:10).isActive = true
CommenterprofileImage.leftAnchor.constraint(equalTo: self.leftAnchor,constant:20).isActive = true
CommenterprofileImage.widthAnchor.constraint(equalToConstant: 70).isActive = true
CommenterprofileImage.heightAnchor.constraint(equalToConstant: 70).isActive = true
commentText.topAnchor.constraint(equalTo: CommenterprofileImage.bottomAnchor,constant:20).isActive = true
commentText.leftAnchor.constraint(equalTo: self.leftAnchor).isActive = true
commentText.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
}
And i want this cell's width to be equal to the view's width,but i want it's height to depend on it's content.
I tried doing this
layout.estimatedItemSize = CGSize(width: view.frame.width, height: 100)
But then my cell's height is 100 and width is less than 100.

Answer 1

You Can do it this way-:
Calculate label height with boundingRect method first-:
func estimatedFrameHeight(text:String) -> CGRect{
let size = CGSize(width: (view.frame.width/2 - 8), height: 1000)
let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
let attribute = [NSFontAttributeName:UIFont.systemFont(ofSize: 11)]
return NSString(string: text).boundingRect(with: size, options: options, attributes: attribute, context: nil)
}
Keep the exact same font you providing to your label,And keep .usesLineFragmentOrigin for multi line label.
Now in CollectionView sizeForItemAt indexPath do this-:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let width = (collectionView.frame.width)
let subDict = subCategoryListArray[indexPath.row]
if let product_name = subDict["product_name"] as? String {
let height = estimatedFrameHeight(text:product_name)
return CGSize(width: width, height: height.height + 70 + 10 + 20)
}
return CGSize(width: 0, height: 0)
}
let height = estimatedFrameHeight(text:product_name) . This will provide you with estimated height as well as width if you need. Now you have your label height calculated you need to add imageView height , y position constraints to make it work.You can get it from here-:
CommenterprofileImage.heightAnchor.constraint(equalToConstant: 70).isActive = true
Height = 70 you have.
And,
CommenterprofileImage.topAnchor.constraint(equalTo: self.topAnchor,constant:10).isActive = true
commentText.topAnchor.constraint(equalTo: CommenterprofileImage.bottomAnchor,constant:20).isActive
Top Constraint is = 10
Top Constraint is = 20
So you need to add this now as you can see I did in answer.
Remark-:
only add ImageView Height if it is above label else not require, just
add height and y padding for what ever you have above label.
Same to calculate exact width for label subtarct leading or trailing
space.
If label covers complete width (No insets subtraction required)-:
func estimatedFrameHeight(text:String) -> CGRect{
let size = CGSize(width: (view.frame.width), height: 1000)
let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
let attribute = [NSFontAttributeName:UIFont.systemFont(ofSize: 11)]
return NSString(string: text).boundingRect(with: size, options: options, attributes: attribute, context: nil)
}
If label is 20 points from leading then subtract that-:
func estimatedFrameHeight(text:String) -> CGRect{
let size = CGSize(width: (view.frame.width - 20), height: 1000)
let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
let attribute = [NSFontAttributeName:UIFont.systemFont(ofSize: 11)]
return NSString(string: text).boundingRect(with: size, options: options, attributes: attribute, context: nil)
}