title: Animate scrolling of UIScrollView with CoreAnimation
body: <p>Sorry for a big question, real question are <strong>bold</strong> in bottom, now some explanation.</p>
  
  <p>I'm use CoreAnimation in my project for animate some objects moving like this.</p>
  
  <pre><code>CABasicAnimation *moveAnimation;        
  moveAnimation=[CABasicAnimation animationWithKeyPath:@"position"];      
  moveAnimation.duration = 2.0;       
  moveAnimation.repeatCount=1;        
  moveAnimation.autoreverses=NO;  
  moveAnimation.delegate = self;
  moveAnimation.fromValue = [NSValue valueWithCGPoint:[crawler.layer position]];
  moveAnimation.fillMode = kCAFillModeForwards;
  moveAnimation.removedOnCompletion = NO;
  CGPoint p;
  moveAnimation.toValue = [NSValue valueWithCGPoint:CGPointMake(100, 100)];
  [crawler.layer addAnimation:moveAnimation forKey:@"moveAnimation"];
  </code></pre>
  
  <p>And now I need to animate scrolling of some UIScrollView. I can't use <code>setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated</code> method, because it can't customise animation duration.</p>
  
  <p>I can make it like this</p>
  
  <pre><code>CGContextRef context = UIGraphicsGetCurrentContext();
  [UIView beginAnimations:nil context:context];
  [UIView setAnimationCurve:UIViewAnimationCurveLinear];
  [UIView setAnimationDuration:2];
  [UIView setAnimationDelegate:self];
  scrollView.contentOffset = CGPointMake(scrollView.contentOffset.x + 200, scrollView.contentOffset.y);
  [UIView commitAnimations];
  </code></pre>
  
  <p>but it's not CoreAnimation, and using 2 different kinds of animation techniques in one app is not a good practice, I think.</p>
  
  <p><strong>Is there a way to use a CoreAnimation to animate scrolling of UIScrollView content to custom point with custom animation duration?</strong>
  P.S. Sorry for the bad English.</p>