Convenience methods to add and animate a shadowPath

gistfile1.txt

- (void)addShadowWithColor:(UIColor *)color alpha:(CGFloat)alpha radius:(CGFloat)radius offset:(CGSize)offset
{
	self.layer.shadowOpacity = alpha;
	self.layer.shadowRadius = radius;
	self.layer.shadowOffset = offset;
	
	if (color)
	{
		self.layer.shadowColor = [color CGColor];
	}
	
	// cannot have masking	
	self.layer.masksToBounds = NO;
}

- (void)updateShadowPathToBounds:(CGRect)bounds withDuration:(NSTimeInterval)duration
{
	CGPathRef oldPath = self.layer.shadowPath;
	CGPathRef newPath = CGPathCreateWithRect(bounds, NULL);
	
	if (oldPath && duration>0)
	{
		CABasicAnimation *theAnimation = [CABasicAnimation animationWithKeyPath:@"shadowPath"];
		theAnimation.duration = duration;
		theAnimation.fromValue = (__bridge id)oldPath;
		theAnimation.toValue = (__bridge id)newPath;
		theAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
		[self.layer addAnimation:theAnimation forKey:@"shadowPath"];
	}
	
	self.layer.shadowPath = newPath;

	CGPathRelease(newPath);
}