measure method

double measure(
  1. int row,
  2. double height
)

Sets an actual row height and returns its change in pixels or cells.

Implementation

double measure(int row, double height) {
  RangeError.checkValidIndex(row, _tree, 'row', length);
  if (!height.isFinite || height <= 0) throw ArgumentError.value(height);
  final delta = height - (_measured[row] ?? estimatedHeight);
  _measured[row] = height;
  for (var index = row + 1; index <= length; index += index & -index) {
    _tree[index] += delta;
  }
  return delta;
}