recursivelyInsertClones() — react Function Reference

Source Code

packages/react-reconciler/src/ReactFiberApplyGesture.js lines 741–784

function recursivelyInsertClones(
  parentFiber: Fiber,
  hostParentClone: Instance,
  parentViewTransition: null | ViewTransitionState,
  visitPhase: VisitPhase,
) {
  const deletions = parentFiber.deletions;
  if (deletions !== null) {
    for (let i = 0; i < deletions.length; i++) {
      const childToDelete = deletions[i];
      trackEnterViewTransitions(childToDelete);
      // Normally we would only mark something as triggering a mutation if there was
      // actually a HostInstance below here. If this tree didn't contain a HostInstances
      // we shouldn't trigger a mutation even though a virtual component was deleted.
      trackHostMutation();
    }
  }

  if (
    parentFiber.alternate === null ||
    (parentFiber.subtreeFlags & MutationMask) !== NoFlags
  ) {
    // If we have mutations or if this is a newly inserted tree, clone as we go.
    let child = parentFiber.child;
    while (child !== null) {
      insertDestinationClonesOfFiber(
        child,
        hostParentClone,
        parentViewTransition,
        visitPhase,
      );
      child = child.sibling;
    }
  } else {
    // Once we reach a subtree with no more mutations we can bail out.
    // However, we must still insert deep clones of the HostComponents.
    recursivelyInsertClonesFromExistingTree(
      parentFiber,
      hostParentClone,
      parentViewTransition,
      visitPhase,
    );
  }
}