ItemExtentEstimator typedef

ItemExtentEstimator = double Function(int index, double crossAxisExtent)

Estimates the main axis extent of the item at index before it is laid out, for a list whose cross axis extent is crossAxisExtent. Called for every item that has not been measured yet, so it must be cheap.

Implementation

typedef ItemExtentEstimator =
    double Function(int index, double crossAxisExtent);