scrollOffsetOf method
Returns the sliver-space scroll offset of key, or null if key is
not in the current visible order (e.g., ancestors collapsed, or key
not registered). The offset corresponds to the node's top edge within
the SliverTree's own scroll extent.
Walks preceding visible nodes and sums their full (non-animated)
extents, preferring measured values from the render pass and falling
back to extentEstimator or defaultExtent for nodes that have
never been laid out.
For scrollables that contain other slivers above the tree, add those slivers' combined extent to the returned value before seeking.
Implementation
double? scrollOffsetOf(
TKey key, {
double Function(TKey key)? extentEstimator,
}) => _scroll.scrollOffsetOf(key, extentEstimator: extentEstimator);