title: UITextView - setting font size of attributedText slow?
body: <p>I'm trying to change the font size of my UITextView's text, which is using attributed text, with the following:</p>
  
  <pre><code>UIFont *font = [self.textView.font fontWithSize:value];
  NSDictionary *attributes = @{ NSFontAttributeName: font };
  
  NSMutableAttributedString *attrString = [self.textView.attributedText mutableCopy];
  [attrString addAttributes:attributes range:NSMakeRange(0, attrString.length)];
  self.textView.attributedText = attrString;
  </code></pre>
  
  <p>However, using this in combination with a slider causes a noticeable slow down. Am I doing this correctly? Simple setting the font size of the <code>textView.font</code> property did not work.</p>
  
  <p>This is how I'm setting the attributed text in the first place:</p>
  
  <pre><code>NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"Neutra church-key brunch farm-to-table disrupt skateboard, bushwick next level organic gentrify street art. Pop-up echo park pork belly pour-over. Bespoke meggings put a bird on it, plaid hashtag farm-to-table YOLO freegan pug pickled jean shorts quinoa gentrify forage. Tumblr butcher echo park, small batch mumblecore banjo trust fund intelligentsia bushwick VHS raw denim."];
  [string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(59, 13)];
  [string addAttribute:(NSString*)NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:NSUnderlineStyleSingle] range:(NSRange){59, 13}];
  
  textView.attributedText = string;
  </code></pre>