applyAppearingPairViewTransition() — react Function Reference

Source Code

packages/react-reconciler/src/ReactFiberApplyGesture.js lines 265–299

function applyAppearingPairViewTransition(child: Fiber): void {
  // Normally these helpers do recursive calls but since insertion/offscreen is forked
  // we call this helper from those loops instead. This must be called only on
  // ViewTransitionComponent that has already had their clones filled.
  if ((child.flags & ViewTransitionNamedStatic) !== NoFlags) {
    const state: ViewTransitionState = child.stateNode;
    // If this is not yet paired, it doesn't mean that we won't pair it later when
    // we find the deletion side. If that's the case then we'll add the names to
    // the clones then.
    if (state.paired) {
      const props: ViewTransitionProps = child.memoizedProps;
      if (props.name == null || props.name === 'auto') {
        throw new Error(
          'Found a pair with an auto name. This is a bug in React.',
        );
      }
      const name = props.name;
      // Note that this class name that doesn't actually really matter because the
      // "new" side will be the one that wins in practice.
      const className: ?string = getViewTransitionClassName(
        props.default,
        props.share,
      );
      if (className !== 'none') {
        const clones = state.clones;
        // If there are no clones at this point, that should mean that there are no
        // HostComponent children in this ViewTransition.
        if (clones !== null) {
          applyViewTransitionToClones(name, className, clones, child);
        }
        scheduleGestureTransitionEvent(child, props.onGestureShare);
      }
    }
  }
}