JList.getSelectedValues()

[sjs]

JList.getSelectedValues() returns values sorted by increasing index order. Is there a way to return the values in the order they were selected? Or do I have to write my own listener and build the array? Seemed like a JTree returns multiple selections in the order they were selected, is that true?

For example if list contains:
1
2
3
4
5

And 5 is selected first, then 3, and then 1. I want the array to be [5,3,1], and not [1,3,5].

Scott

[eRaaaa]

Mhm, I have never been done before, but my workaround is:

- override the getSelectedValues() method in JList
- write your own ListSelectionModel (perhaps extend DefaultListSelectionModel)

class SelectModel extends DefaultListSelectionModel {

	private List<Integer> indices = new ArrayList<Integer>();

	/**
	 * @return the indices
	 */
	public List<Integer> getIndices() {
		return indices;
	}

	@Override
	public void addSelectionInterval(int index0, int index1) {
		addIndices(index0, index1);
		super.addSelectionInterval(index0, index1);
	}

	@Override
	public void setSelectionInterval(int index0, int index1) {
		indices.clear();
		addIndices(index0, index1);
		super.setSelectionInterval(index0, index1);
	}

	private void addIndices(int index0, int index1) {
		if (index0 < index1) {
			for (int i = index0; i <= index1; i++) {
				indices.add(i);
			}
		} else {
			for (int i = index0; i >= index1; i--) {
				indices.add(i);
			}
		}
	}
}

and

			@Override
			public Object[] getSelectedValues() {
				SelectModel selectmodel = (SelectModel) getSelectionModel();
				List<Integer> indices = selectmodel.getIndices();
				ListModel model = getModel();
				Object[] obj = new Object[indices.size()];
				int i = 0;
				for (Integer index : indices) {
					obj[i++] = model.getElementAt(index);
				}
				return obj;
			}

simple demo:

	public static void main(String[] args) throws Exception {
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				JFrame frame = new JFrame();
				JPanel panel = new JPanel();
				final JList list = new JList() {
					{
						DefaultListModel model = new DefaultListModel();
						model.addElement(1);
						model.addElement(2);
						model.addElement(3);
						model.addElement(4);
						setModel(model);
					}

					@Override
					public Object[] getSelectedValues() {
						SelectModel selectmodel = (SelectModel) getSelectionModel();
						List<Integer> indices = selectmodel.getIndices();
						ListModel model = getModel();
						Object[] obj = new Object[indices.size()];
						int i = 0;
						for (Integer index : indices) {
							obj[i++] = model.getElementAt(index);
						}
						return obj;
					}

				};
				panel.add(list);
				JButton btn = new JButton("get selected values");
				btn.addActionListener(new ActionListener() {
					@Override
					public void actionPerformed(ActionEvent e) {
						System.out.println(Arrays.toString(list.getSelectedValues()));
					}
				});
				panel.add(btn);
				list.setSelectionModel(new SelectModel());
				frame.add(panel);
				frame.pack();
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
				frame.setLocationRelativeTo(null);
				frame.setVisible(true);
			}
		});
	}

EDIT: deselect/removeIndexInterval : its your part ^^