CATextLayer and CAConstraint

FROM : Aaron Tait
DATE : Sun Nov 18 09:00:09 2007

I've been pulling my hair out trying to get a CATextLayer to work with 
a couple of CAConstraints. The following is a method implemented in a 
layer backed view and the following call is made in the view's 
awakeFromNib:
self.layer.layoutManager = [CAConstraintLayoutManager layoutManager];

The method is as follows:

-(void)addFileNameLayer:(NSString *)fileName
{
   CATextLayer * fileNameLayer = [CATextLayer layer];
   fileNameLayer.string = fileName;
   fileNameLayer.name = @"fileNameLayer";
   fileNameLayer.fontSize = 14.0;
   fileNameLayer.alignmentMode = kCAAlignmentCenter;
   fileNameLayer.wrapped = YES;
   fileNameLayer.anchorPoint = CGPointMake(0.5, 0.5);
   fileNameLayer.bounds = CGRectMake(0, 0, 320, 50);
   [fileNameLayer addConstraint:[CAConstraint 
constraintWithAttribute:kCAConstraintMidX relativeTo:@"superlayer" 
attribute:kCAConstraintMidX]];
   [fileNameLayer addConstraint:[CAConstraint 
constraintWithAttribute:kCAConstraintMidY relativeTo:@"superlayer" 
attribute:kCAConstraintMidY offset:-100]];
   [self.layer addSublayer:fileNameLayer];
}

When the code executes, it displays nothing. I also add another plain 
old CALayer before I call this method with similar constraints and it 
works out fine. Anyone help would be appreciated.

-Aaron