Get UITextView measureHeight

UITextView+Helper.m

@interface UITextView (Helper)

- (CGFloat)measureHeight;

@end

#import "UITextView+Helper.h"

@implementation UITextView (Helper)

- (CGFloat)measureHeight
{
    if ([self respondsToSelector:@selector(snapshotViewAfterScreenUpdates:)])
    {
        // This is the code for iOS 7. contentSize no longer returns the correct value, so
        // we have to calculate it.
        //
        // This is partly borrowed from HPGrowingself, but I've replaced the
        // magic fudge factors with the calculated values (having worked out where
        // they came from)
        
        CGRect frame = self.bounds;
        
        // Take account of the padding added around the text.
        
        UIEdgeInsets textContainerInsets = self.textContainerInset;
        UIEdgeInsets contentInsets = self.contentInset;
        
        CGFloat leftRightPadding = textContainerInsets.left + textContainerInsets.right + self.textContainer.lineFragmentPadding * 2 + contentInsets.left + contentInsets.right;
        CGFloat topBottomPadding = textContainerInsets.top + textContainerInsets.bottom + contentInsets.top + contentInsets.bottom;
        
        frame.size.width -= leftRightPadding;
        frame.size.height -= topBottomPadding;
        
        NSString *textToMeasure = self.text;
        if ([textToMeasure hasSuffix:@"\n"])
        {
            textToMeasure = [NSString stringWithFormat:@"%@-", self.text];
        }
        
        // NSString class method: boundingRectWithSize:options:attributes:context is
        // available only on ios7.0 sdk.
        
        NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
        [paragraphStyle setLineBreakMode:NSLineBreakByWordWrapping];
        
        NSDictionary *attributes = @{ NSFontAttributeName: self.font, NSParagraphStyleAttributeName : paragraphStyle };
        
        CGRect size = [textToMeasure boundingRectWithSize:CGSizeMake(CGRectGetWidth(frame), MAXFLOAT)
                                                  options:NSStringDrawingUsesLineFragmentOrigin
                                               attributes:attributes
                                                  context:nil];
        
        CGFloat measuredHeight = ceilf(CGRectGetHeight(size) + topBottomPadding);
        return measuredHeight;
    }
    else
    {
        return self.contentSize.height;
    }
}

@end