row method
Returns the list of RenderBox objects that are on the given row, in column order, starting with the first column.
This is a lazily-evaluated iterable.
Implementation
Iterable<RenderBox> row(int y) sync* {
final int start = y * columns;
final int end = (y + 1) * columns;
for (int xy = start; xy < end; xy += 1) {
final RenderBox child = _children[xy];
if (child != null)
yield child;
}
}