CODEWITHSUNDEEP
javaswingarraylistjlist
user1132760
user1132760

Reputation:

Java Swing using JList with an ArrayList<>

Basically, I've got a CD Library that holds instances of a CD ArrayList<>, I've then got a people ArrayList<> that can "borrow" CD's... from that CD's are added to an available, or unavailable list.

public CDStore(String storeNme) {
        storeName = storeNme;
        discsArray = new ArrayList<CD>();
        peopleArray = new ArrayList<Person>();
    }

By using a JList, I'm trying to make the elements of the list equal the instances of CD.

So... item1 in the list would be the CD at index 0, item 2 = index 1 and so on....

String[] entries = ??????????????????;
        JList listOfCD = new JList(entries);
        listOfCD.setVisibleRowCount(4);
        JScrollPane listPane = new JScrollPane(listOfCD);
        JTextField valueField = new JTextField("None", 7);

Thankyou.

Upvotes: 0

Views: 4814

Answers (2)

alexvetter
alexvetter

Reputation: 2006

Your CDStore could implement the interface ListModel. Than you can use the CDStore as a model for your JList.

CDStore store = new CDStore("Store");
// add some CDs

JList listOfCD = new JList(store);
listOfCD.setVisibleRowCount(4);
JScrollPane listPane = new JScrollPane(listOfCD);
JTextField valueField = new JTextField("None", 7);

Here is example implementation of CDStore implements ListModel. Everytime the discsArray changes you should call the method fireContentsChanged.

public class CDStore implements ListModel {
    private String storeName;
    private List<CD> discsArray;
    private List<Person> peopleArray;

    public CDStore(String storeNme) {
        storeName = storeNme;
        discsArray = new ArrayList<CD>();
        peopleArray = new ArrayList<Person>();
    }

    //your methods

    //ListModel
    private List<ListDataListener> listener = new ArrayList<ListDataListener>();

    public void addListDataListener(ListDataListener l) {
        listener.add(l);
    }

    public void removeListDataListener(ListDataListener l) {
        listener.remove(l);
    }

    protected void fireContentsChanged() {
        for (ListDataListener l : listener) {
            l.contentsChanged(new ListDataEvent(this, ListDataEvent.CONTENTS_CHANGED, 0, discsArray.size()-1));
        }
    }

    public Object getElementAt(int index) {
        return discsArray.get(index);
    }

    public int getSize() {
        return discsArray.size()
    }
}

Upvotes: 2

montardon
montardon

Reputation: 411

If you have a method to retrieve CD name, let's call it getCDName(), you can try 

String[] entries = new String[discsArray.length];
int index = 0;
for (CD cd: discsArray) {
     entries[index++] = cd.getCDName();
}

This should fill in your entries array.

Upvotes: 1

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