How to check if UILabel is truncated?

Question

I have a UILabel that can be varying lengths depending on whether or not my app is running in portrait or landscape mode on an iPhone or iPad. When the text is

Answer 1

Swift 3

You can count the number of lines after assigning the string and compare to the max number of lines of the label.

import Foundation
import UIKit

extension UILabel {
    
    func countLabelLines() -> Int {
        // Call self.layoutIfNeeded() if your view is uses auto layout
        let myText = self.text! as NSString
        let attributes = [NSFontAttributeName : self.font]
        
        let labelSize = myText.boundingRect(with: CGSize(width: self.bounds.width, height: CGFloat.greatestFiniteMagnitude), options: NSStringDrawingOptions.usesLineFragmentOrigin, attributes: attributes, context: nil)
        return Int(ceil(CGFloat(labelSize.height) / self.font.lineHeight))
    }
    
    func isTruncated() -> Bool {
        guard numberOfLines > 0 else { return false }
        return countLabelLines() > numberOfLines
    }
}

Answer 2

Because all the answers above use depreciated methods, i thought this could be useful:

- (BOOL)isLabelTruncated:(UILabel *)label
{
    BOOL isTruncated = NO;

    CGRect labelSize = [label.text boundingRectWithSize:CGSizeFromString(label.text) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName : label.font} context:nil];

    if (labelSize.size.width / labelSize.size.height > label.numberOfLines) {

        isTruncated = YES;
    }

    return isTruncated;
}

Answer 3

To add to iDev 's answer, you should use intrinsicContentSize instead of frame, to make it works for Autolayout

- (BOOL)isTruncated:(UILabel *)label{
        CGSize sizeOfText = [label.text boundingRectWithSize: CGSizeMake(label.intrinsicContentSize.width, CGFLOAT_MAX)
                                                     options: (NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                                  attributes: [NSDictionary dictionaryWithObject:label.font forKey:NSFontAttributeName] context: nil].size;

        if (self.intrinsicContentSize.height < ceilf(sizeOfText.height)) {
        return YES;
    }
    return NO;
}

Answer 4

extension UILabel {

public func resizeIfNeeded() -> CGFloat? {
    guard let text = text, !text.isEmpty else { return nil }

    if isTruncated() {
        numberOfLines = 0
        sizeToFit()
        return frame.height
    }
    return nil
}

func isTruncated() -> Bool {
    guard let text = text, !text.isEmpty else { return false }

    let size: CGSize = text.size(withAttributes: [NSAttributedStringKey.font: font])
    return size.width > self.bounds.size.width
    }
}

You can calculate the width of the string and see if the width is greater than label width.

Answer 5

To handle iOS 6 (yes, some of us still have to), here's yet another expansion to @iDev's answer. The key takeaway is that, for iOS 6, to make sure your UILabel's numberOfLines is set to 0 before calling sizeThatFits; if not, it'll give you a result that says "the points to draw numberOfLines worth of height" is needed to draw the label text.

- (BOOL)isTruncated
{
    CGSize sizeOfText;

    // iOS 7 & 8
    if([self.text respondsToSelector:@selector(boundingRectWithSize:options:attributes:context:)])
    {
        sizeOfText = [self.text boundingRectWithSize:CGSizeMake(self.bounds.size.width,CGFLOAT_MAX)
                                             options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                          attributes:@{NSFontAttributeName:self.font}
                                             context:nil].size;
    }
    // iOS 6
    else
    {
        // For iOS6, set numberOfLines to 0 (i.e. draw label text using as many lines as it takes)
        //  so that siteThatFits works correctly. If we leave it = 1 (for example), it'll come
        //  back telling us that we only need 1 line!
        NSInteger origNumLines = self.numberOfLines;
        self.numberOfLines = 0;
        sizeOfText = [self sizeThatFits:CGSizeMake(self.bounds.size.width,CGFLOAT_MAX)];
        self.numberOfLines = origNumLines;
    }

    return ((self.bounds.size.height < sizeOfText.height) ? YES : NO);
}

Answer 6

I have written a category for working with UILabel's truncation. Works on iOS 7 and later. Hope it helps ! uilabel tail truncation

@implementation UILabel (Truncation)

- (NSRange)truncatedRange
{
    NSTextStorage *textStorage = [[NSTextStorage alloc] initWithAttributedString:[self attributedText]];

    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    [textStorage addLayoutManager:layoutManager];

    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:[self bounds].size];
    textContainer.lineFragmentPadding = 0;
    [layoutManager addTextContainer:textContainer];

    NSRange truncatedrange = [layoutManager truncatedGlyphRangeInLineFragmentForGlyphAtIndex:0];
    return truncatedrange;
}

- (BOOL)isTruncated
{
    return [self truncatedRange].location != NSNotFound;
}

- (NSString *)truncatedText
{
    NSRange truncatedrange = [self truncatedRange];
    if (truncatedrange.location != NSNotFound)
    {
        return [self.text substringWithRange:truncatedrange];
    }

    return nil;
}

@end