markPreserveProgress method

void markPreserveProgress(
  1. TKey key
)

Sets SlideAnimation.preserveProgressOnRebatch = true on the slide entry for key. Tolerant of unregistered keys and inactive slides (no-op).

Only ever sets the flag: the engine clears it implicitly when the slide entry is destroyed (settles, cancelled, or replaced via composition). The render layer should never need to clear explicitly.

Implementation

void markPreserveProgress(TKey key) {
  final nid = _nids[key];
  if (nid == null || nid >= _slideByNid.length) return;
  final entry = _slideByNid[nid];
  if (entry == null) return;
  entry.preserveProgressOnRebatch = true;
}