NSTextField's attributed string is delayed in rendering

Question

I've got an Label (NSTextField) in IB that's bound to a controller. The controller, on awakeFromNIB, sets the attributedStringValue of the label to contain some coloured text and a link or two.

When you see the label it contains the correct string value, but some of the formatting is lost - until you click on the label, and it updates to contain the correct formatting.

I'm using this code to set the value:

[self.testTextField setAllowsEditingTextAttributes:YES];
[self.testTextField setSelectable:YES];
NSMutableAttributedString *linkString = [[NSMutableAttributedString alloc] initWithString:@"hit this "];

[linkString beginEditing];

NSMutableAttributedString* attrString = [[NSMutableAttributedString alloc] initWithString:@"link"];
NSRange range = NSMakeRange(0, [attrString length]);

[attrString addAttribute:NSLinkAttributeName value:[[NSURL URLWithString:@"http://google.com"] absoluteString] range:range];
[attrString addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:NSUnderlinePatternDot] range:range];
[attrString addAttribute:NSForegroundColorAttributeName value:[NSColor blackColor] range:range];
[linkString appendAttributedString:attrString];

[linkString appendAttributedString:[[NSAttributedString alloc] initWithString:@" to search"]];

[linkString addAttribute:NSForegroundColorAttributeName value:[NSColor redColor] range:NSMakeRange(0, [linkString length])];

[linkString endEditing];

[self.testTextField setAttributedStringValue:linkString];

Based on this example, you'll see the string coloured red and in the default Label font. Then when you click on the label the font changes size and face and the link magically renders.

Any ideas on how to get the string to render correctly the first time?

You don't need to call beginEditing and endEditing when you are constructing an attributed string. These methods are only for use when the string is being monitored for changes, such as NSTextStorage for an NSTextView. — Rob Keniger
Also, you say the text field is "bound" to the controller. The use of the word "bound" implies that you're using Cocoa Bindings, but it seems like you are not, as you are setting the value of the text field programmatically. Is the text field's attributedStringValue binding actually bound to anything? — Rob Keniger
@RobKeniger It's an IBOutlet which is 'bound' (what is the right term for that?) — d2kagw
@RobKeniger I tried removing the begin & endEditing method calls but no success. — d2kagw
Can you just call [textField setNeedsDisplay:YES] to force a redraw? — Rob Keniger

Mike Knippers Mike Knippers · Accepted Answer · 2012-10-12T16:46:17

I ran into this same problem. The solution I found was to explicitly set the NSFontAttributeName on the attributed string. I created an NSFont object that matched the font I had set in IB for my textfield and set that attribute like so:

NSFont *font = [NSFont fontWithName:@"Lucida Grande" size:(CGFloat)13.0];
[attrString addAttribute:NSFontAttributeName value:font range:range];

NSTextField's attributed string is delayed in rendering

2 Answers