add method

void add(
  1. RenderBox child, {
  2. int? flex,
  3. FlexFit? fit,
})

Adds child at the end of the child list with optional flex metadata.

Implementation

void add(RenderBox child, {int? flex, FlexFit? fit}) {
  _validateFlex(flex);
  final wasChild = identical(child.parent, this);
  final previous = _childrenData[child];
  final metadataChanged = previous?.flex != flex || previous?.fit != fit;
  if (!wasChild) {
    adoptChild(child);
  }
  _childrenData[child] = FlexChildData(flex: flex, fit: fit);
  if (wasChild && metadataChanged) {
    markNeedsLayout();
  }
}