How to check if a UIView is out of its superview bounds

Question

I have a view with a pan gesture and a UIPushBehavior hooked up to it an wanted to know if its possible to check when the view is out the superviews bounds. Basically the user tosses the view and I want to run some animation when the view is out of the screen. Couldn't figure out how to do this. Thanks.

Answer 1

If you want to check if it is entirely out of it's superview bounds you can do this

if (!CGRectContainsRect(view.superview.bounds, view.frame))
{
    //view is completely out of bounds of its super view.
}

If you want to check if just part of it is out of bounds you can do

if (!CGRectEqualToRect(CGRectIntersection(view.superview.bounds, view.frame), view.frame))
{
   //view is partially out of bounds
}

Answer 2

Unfortunately, Philipp's answer on partially out of bounds check is not fully correct in this line: v1.bounds.intersection(v2.frame).width > 0) && (v1.bounds.intersection(v2.frame).height > 0

Intersection size can be bigger than zero and still the view would lie inside the superview bounds.

Also it turned out that I can't use equal(to: CGRect) safely because of CGFloat accuracy.

Here is corrected version:

func outOfSuperviewBounds() -> Bool {
  guard let superview = self.superview else {
    return true
  }
  let intersectedFrame = superview.bounds.intersection(self.frame)
  let isInBounds = fabs(intersectedFrame.origin.x - self.frame.origin.x) < 1 &&
                   fabs(intersectedFrame.origin.y - self.frame.origin.y) < 1 &&
                   fabs(intersectedFrame.size.width - self.frame.size.width) < 1 &&
                   fabs(intersectedFrame.size.height - self.frame.size.height) < 1
  return !isInBounds
}