gistfile1.txt

- (void)adjustFontSizeToFit
{
    UIFont *font = self.font;
    CGSize size = self.frame.size;
    for (CGFloat maxSize = self.font.pointSize; maxSize >= self.minimumFontSize; maxSize -= 1.f)
    {
        font = [font fontWithSize:maxSize];
        CGSize constraintSize = CGSizeMake(size.width, MAXFLOAT);
        NSString *text = self.text;
        if ([text isEmptyAfterTrimmed]) {
            text = self.placeholder;
        }
        CGRect labelSize = [text boundingRectWithSize:constraintSize
                                              options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingTruncatesLastVisibleLine)
                                           attributes:@{NSFontAttributeName:font}
                                              context:nil];
        // Keeping the width constant if given text requires more height , decrease the font size.
        if(labelSize.size.height <= size.height)
        {
            self.font = font;
            [self setNeedsLayout];
            break;
        }
    }
    // set the font to the minimum size anyway
    self.font = font;
    [self setNeedsLayout];
}