Draws a box around a view and then animates it to grow vertically. Originally I was going to use this to display errors underneath UITexFields.

AddErrorBox

-(void)addBox
{
    self.layer.masksToBounds = NO;
    CALayer *errorLayer;
    errorLayer = [CALayer layer];
    errorLayer.backgroundColor = [UIColor blueColor].CGColor;
    errorLayer.frame = CGRectMake(0,0, self.frame.size.width, self.frame.size.height);
    errorLayer.cornerRadius = 0.0f;
    CALayer *bgLayer = [CALayer layer];
    bgLayer.frame = errorLayer.frame;
    bgLayer.backgroundColor = [UIColor whiteColor].CGColor;

    [self.layer insertSublayer:errorLayer atIndex:0];
    [self.layer insertSublayer:bgLayer atIndex:1];

    errorLayer.anchorPoint = CGPointMake(0.5,0.3);
    CGRect startBounds = self.layer.bounds;
    CGRect stopBounds = CGRectMake(0.0f, 0.0f, self.layer.frame.size.width+5, self.layer.frame.size.height*2.5);

    CABasicAnimation* boundAnim = [CABasicAnimation animationWithKeyPath:@"bounds"];
    boundAnim.fromValue = [NSValue valueWithCGRect:startBounds];
    boundAnim.toValue = [NSValue valueWithCGRect:stopBounds];

    CABasicAnimation* cornerAnim = [CABasicAnimation animationWithKeyPath:@"cornerRadius"];
    cornerAnim.fromValue = [NSNumber numberWithFloat:0.0];
    cornerAnim.toValue = [NSNumber numberWithFloat:5.0];

    CABasicAnimation* fadeAnim = [CABasicAnimation animationWithKeyPath:@"opacity"];
    fadeAnim.fromValue = [NSNumber numberWithFloat:0.0];
    fadeAnim.toValue = [NSNumber numberWithFloat:1.0];

    //amo,atopm group
    CAAnimationGroup* group = [CAAnimationGroup animation];
    group.animations = [NSArray arrayWithObjects:fadeAnim, boundAnim,cornerAnim, nil];
    group.duration = 0.15;

    [errorLayer addAnimation:group forKey:@"BoxAnimation"];
    errorLayer.bounds = stopBounds;
}