Handling UIDynamicBehaviors when removing the respective UIView

Question

Periodically, I add a UIView to the UIDynamicAnimator, which has some behaviours of its own. But when I remove the UIView from it's superview (when it falls offscreen) the UIDynamicAnimator still keeps the UIView's behaviours in its 'behaviors' property.

My question is, exactly what is the best approach to handling the behaviours in a UIDynamicAnimator?

Do I have to manually keep track of all the behaviours pertaining to that UIView and manually remove them before removing the UIView from the view hierarchy?

Answer 1

[myBehavior removeItem:item] does not throw an exception if item is not part of myBehavior, so what you could do is have a generic removeView method that removes a view from all behaviors that could possibly pertain to it, something like:

- (void) removeView: (UIView *) view{
  [_gravity removeItem: view];
  [_collisions removeItem:view];
  [_otherBehavior removeItem:view];
  //and et cetra for all of your behaviors
  [self.view removeItem: view];
}

Which could be called whenever you need to remove a view. Even if, say, the view is not part of _otherBehavior this method would still properly remove the view.