Counting the number of lines in a UITextView, lines wrapped by frame size

Question

I wanted to know when a text is wrapped by the frame of the text view is there any delimiter with which we can identify whether the text is wrapped or not.

For insta

Answer 1

I found the perfect solution to this problem in Apple's Text Layout Programming Guide. Here is the solution Apple provides:

NSLayoutManager *layoutManager = [textView layoutManager];
unsigned numberOfLines, index;
unsigned numberOfGlyphs = [layoutManager numberOfGlyphs];
NSRange lineRange;

for (numberOfLines = 0, index = 0; index < numberOfGlyphs; numberOfLines++){
    (void) [layoutManager lineFragmentRectForGlyphAtIndex:index effectiveRange:&lineRange];
    index = NSMaxRange(lineRange);
}

This could easily be written into an extension for UITextView, or as a standalone method taking in a UITextView object as a parameter

Answer 2

Improved and update Luke Chase's answer to Swift 5, XCode 11, iOS 13 to get text view number of lines and autoresize table view cell height.

1. You can use storyboard with static cell height to design it as you want. Make UITextView scroll enable: false (disable scroll).

2. In viewDidLoad add your estimated row height and your textView delegate.

override func viewDidLoad() {
        super.viewDidLoad()

        quoteTextView.delegate = self
        tableView.estimatedRowHeight = 142

    }

3. Add table view delegates for heightForRowAt:

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

4. Conform to UITextViewDelegate to listen when user inputs text.

extension ViewController: UITextViewDelegate {
    func textViewDidChange(_ textView: UITextView) {
        // Refresh tableView cell
        if textView.numberOfLines > 2 { // textView in storyboard has two lines, so we match the design
            // Animated height update
            DispatchQueue.main.async {
                self.tableView?.beginUpdates()
                self.tableView?.endUpdates()
            }
        }
    }
}

5. Add UITextView extension so you avoid redundant code and use all over the app.

extension UITextView {
    var numberOfLines: Int {
        // Get number of lines
        let numberOfGlyphs = self.layoutManager.numberOfGlyphs
        var index = 0, numberOfLines = 0
        var lineRange = NSRange(location: NSNotFound, length: 0)

        while index < numberOfGlyphs {
            self.layoutManager.lineFragmentRect(forGlyphAt: index, effectiveRange: &lineRange)
          index = NSMaxRange(lineRange)
          numberOfLines += 1
        }

        return numberOfLines
    }
}

-> Do not forgot to disable uitextview scroll. Cheers!<-

Preview

Answer 3

This variation takes into account how you wrap your lines and the max size of the UITextView, and may output a more precise height. For example, if the text doesn't fit it will truncate to the visible size, and if you wrap whole words (which is the default) it may result in more lines than if you do otherwise.

UIFont *font = [UIFont boldSystemFontOfSize:11.0];
CGSize size = [string sizeWithFont:font 
                      constrainedToSize:myUITextView.frame.size 
                      lineBreakMode:UILineBreakModeWordWrap]; // default mode
float numberOfLines = size.height / font.lineHeight;

Answer 4

You need to use the lineHeight property, and font lineHeight:

Objective-C

int numLines = txtview.contentSize.height / txtview.font.lineHeight;

Swift

let numLines = (txtview.contentSize.height / txtview.font.lineHeight) as? Int

I am getting correct number of lines, hope it help you also.

Answer 5

   func numberOfLines(textView: UITextView) -> Int {
    let layoutManager = textView.layoutManager
    let numberOfGlyphs = layoutManager.numberOfGlyphs
    var lineRange: NSRange = NSMakeRange(0, 1)
    var index = 0
    var numberOfLines = 0

    while index < numberOfGlyphs {
        layoutManager.lineFragmentRect(forGlyphAt: index, effectiveRange: &lineRange)
        index = NSMaxRange(lineRange)
        numberOfLines += 1
    }
    return numberOfLines
}

Working Fine for me

Answer 6

Swift 5.0

extension UITextView {
    func sizeFit(width: CGFloat) -> CGSize {
        let fixedWidth = width
        let newSize = sizeThatFits(CGSize(width: fixedWidth, height: .greatestFiniteMagnitude))
        return CGSize(width: fixedWidth, height: newSize.height)
    }

    func numberOfLine() -> Int {
        let size = self.sizeFit(width: self.bounds.width)
        let numLines = Int(size.height / (self.font?.lineHeight ?? 1.0))
        return numLines
    }
}