How to truncate UITextView contents to fit a reduced size?

Question

I\'m having real trouble getting my head around this issue.

As the title suggests, I have several UITextViews on a view in an iPhone application. I am programmatically c

Answer 1

Original Answer (iOS 6 and below)

Sadly, UILabel with numberOfLines wont do it if you need the view to be editable. Or you want UITextView's (native) vertical alignment.

Here's an NSString category that deletes words from a string, according to it's size in a rect:

@interface NSString (StringThatFits)
- (NSString *)stringByDeletingWordsFromStringToFit:(CGRect)rect
                                         withInset:(CGFloat)inset
                                         usingFont:(UIFont *)font
@end

@implementation NSString (StringThatFits)
- (NSString *)stringByDeletingWordsFromStringToFit:(CGRect)rect
                                         withInset:(CGFloat)inset
                                         usingFont:(UIFont *)font
{
    NSString *result = [self copy];
    CGSize maxSize = CGSizeMake(rect.size.width  - (inset * 2), FLT_MAX);
    CGSize size = [result sizeWithFont:font
                           constrainedToSize:maxSize
                               lineBreakMode:UILineBreakModeWordWrap];
    NSRange range;

    if (rect.size.height < size.height)
        while (rect.size.height < size.height) {

            range = [result rangeOfString:@" "
                                        options:NSBackwardsSearch];

            if (range.location != NSNotFound && range.location > 0 ) {
                result = [result substringToIndex:range.location];
            } else {
                result = [result substringToIndex:result.length - 1];
            }

            size = [result sizeWithFont:font
                            constrainedToSize:maxSize
                                lineBreakMode:UILineBreakModeWordWrap];
        }

    return result;
}
@end

For a UITextView, use an inset of 8 to account for the way UIKit draws them:

CGRect rect = aTextView.frame;
NSString *truncatedString = [theString stringByDeletingWordsFromStringToFit:rect
                                     withInset:8.f
                                     usingFont:theTextView.font];

Updated Answer (iOS 7)

Now UITextView uses TextKit internally, it's much easier.

Rather than truncating the actual string, set the text (or attributedText) property to the whole string and truncate the amount of text displayed in the container (just like we do with UILabel):

self.textView.scrollEnabled = NO;
self.textView.textContainer.maximumNumberOfLines = 0;
self.textView.textContainer.lineBreakMode = NSLineBreakByTruncatingTail;