import java.util.ArrayList;
import java.util.List;

import javafx.scene.Node;
import javafx.scene.layout.GridPane;

public class SpecialGridPane extends GridPane {
    List<NodeParent> list = new ArrayList<>();

    public void addChild(int row, int column, Node node) {
        list.add(new NodeParent(row, column, node));
        setConstraints(node, column, row);
        getChildren().add(node);
    }

    public Node getChild(int row, int column) {
        for (NodeParent node : list) {
            if (node.getRow() == row && node.getColumn() == column)
                return node.getNode();
        }
        return null;
    }
}

class NodeParent {
    private int row;
    private int column;
    private Node node;

    public NodeParent(int row, int column, Node node) {
        this.row = row;
        this.column = column;
        this.node = node;
    }

    public int getRow() {
        return row;
    }

    public int getColumn() {
        return column;
    }

    public Node getNode() {
        return node;
    }
}