restoreOffset method Null safety

void restoreOffset(
  1. double offset,
  2. {bool initialRestore = false}

Called by context to restore the scroll offset to the provided value.

The provided value has previously been provided to the context by calling ScrollContext.saveOffset, e.g. from saveOffset.

This method may be called right after the scroll position is created before layout has occurred. In that case, initialRestore is set to true and the viewport dimensions will not be known yet. If the context doesn't have any information to restore the scroll offset this method is not called.

The method may be called multiple times in the lifecycle of a ScrollPosition to restore it to different scroll offsets.


void restoreOffset(double offset, {bool initialRestore = false}) {
  assert(initialRestore != null);
  assert(offset != null);
  if (initialRestore) {
  } else {