Auto Layout and UIScrollView Tutorial

gistfile1.swift

// -- animate the placements of our auto layout constraints -- //
// Place the scroll view slightly offset from center before animating //
self.view.layoutIfNeeded()
self.asvScrollView.center = CGPointMake(CGRectGetMidX(self.view.frame), CGRectGetHeight(self.view.frame)/8.0)

UIView.animateWithDuration(1.75, animations: { () -> Void in
  // apply custom constraints to our scroll view //
  self.asvApplyHeightAndWidthConstraints()
  self.asvApplyCenteringConstraints()
  self.view.layoutIfNeeded()
}) { (animated) -> Void in
  // -- animation completion block -- //
  // Once the initial animation is complete we animate the //
  // contents of the scroll view by changing its content offset. //
  self.asvScrollView.setContentOffset(CGPointMake(CGRectGetMaxX(self.asvLeftView.frame), 0), animated: true)
}