detach method
override
Mark this render object as detached from its PipelineOwner.
Typically called only from the parent's detach, and by the owner to mark the root of a tree as detached.
Subclasses with children should override this method to
detach all their children after calling the inherited method,
as in super.detach()
.
Implementation
@override
void detach() {
// It's possible that the renderObject be detached during mouse events
// dispatching, set the [MouseTrackerAnnotation.validForMouseTracker] false to prevent
// the callbacks from being called.
_validForMouseTracker = false;
super.detach();
}