J-WatchList/src/main/data/ListOfWatchList.java

package data;

import java.util.ArrayList;

//Singleton pattern from https://www.tutorialspoint.com/java/java_using_singleton.htm
public class ListOfWatchList {
    private static ListOfWatchList lowl = new ListOfWatchList();
    private ArrayList<WatchList> wlists;

    private ListOfWatchList() {
        wlists = new ArrayList<WatchList>();
    }

    public static ListOfWatchList getList() {
        return lowl;
    }

    public void addWatchList(WatchList wlist) {
        if (!(wlists.contains(wlist))) {
            wlists.add(wlist);
        }
    }

    public void delWatchList(WatchList wlist) {
        wlists.remove(wlist);
    }

    public WatchList getWatchList(int index) {
        return (WatchList) wlists.get(index);
    }
}