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

Use this (where _text_v is your text view):

-(NSInteger) linesCount {
    return _text_v.contentSize.height/_text_v.font.lineHeight;
}

Answer 2

Swift 3:

let layoutManager:NSLayoutManager = textView.layoutManager
let numberOfGlyphs = layoutManager.numberOfGlyphs
var numberOfLines = 0
var index = 0
var lineRange:NSRange = NSRange()

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

print(numberOfLines)

Answer 3

I think that you can try to use NSLayoutManager:

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

Ref

CountLines

Answer 4

Swift 4 version of Luke Chase's answer

let numberOfGlyphs = textView.layoutManager.numberOfGlyphs
var index = 0, numberOfLines = 0
var lineRange = NSRange(location: NSNotFound, length: 0)

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

Answer 5

I spent a lot of time trying to calculate in real time the number of lines for an input TextView (say a chat text entry box) and the only solution that works in such a case is Luke Chase's (for some reason the frame.height approach appears to update only ever 3rd or fourth letter typed into a textView and so is not accurate).

As a commenter mentioned however, there is a small bug in which a user generated line breaks ("\n" or keyboard return press) are not properly accounted for. Even stranger, it only "misses" the first such line-break, any subsequent ones are correctly captured (say you go to the line 4 times it will return only 3 lines clearly missing the first line break).

So to go around that bug I simple look record the first such line-break (character "\n") and manually add a line to the # of lines that the gliph method returns.

In code that gives:

    func offSetTableViewIfNeeded() {
    let numberOfGlyphs = textView.layoutManager.numberOfGlyphs
    var index : Int = 0
    var lineRange = NSRange(location: NSNotFound, length: 0)
    var currentNumOfLines : Int = 0
    var numberOfParagraphJump : Int = 0

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

        // Observing whether user went to line and if it's the first such line break, accounting for it.
        if textView.text.last == "\n", numberOfParagraphJump == 0 {
            numberOfParagraphJump = 1
        }
    }

    currentNumOfLines += numberOfParagraphJump

    print("Number of lines is:", currentNumOfLines)

Hope this helps others who've been struggling with the super weird behavior of input textView (can't understand why Apple does not provide a # of line method out of the box!).

Answer 6

Swift extension:

Using @himanshu padia answer

//MARK: - UITextView
extension UITextView{

    func numberOfLines() -> Int{
        if let fontUnwrapped = self.font{
            return Int(self.contentSize.height / fontUnwrapped.lineHeight)
        }
        return 0
    }

}

Usage : yourTextView.numberOfLines()

be aware that if for some reason the font of the text view is nil, the return will be zero.