dropChild method

  1. @override
void dropChild (covariant RenderObject child)
override

Called by subclasses when they decide a render object is no longer a child.

Only for use by subclasses when changing their child lists. Calling this in other cases will lead to an inconsistent tree and probably cause crashes.

Implementation 

@override
void dropChild(RenderObject child) {
  assert(_debugCanPerformMutations);
  assert(child != null);
  assert(child.parentData != null);
  child._cleanRelayoutBoundary();
  child.parentData.detach();
  child.parentData = null;
  super.dropChild(child);
  markNeedsLayout();
  markNeedsCompositingBitsUpdate();
  markNeedsSemanticsUpdate();
}