Jlist Custom Cellrender

Question

I’d like to make a Cor yield with JPanel so that they would be as follows:

It would consist of a JPanel, another JPanel inside that would have changed the background and two JTextField or JLabel

I tried to understand how the CellRender but nobody explains right

public class CustomContactCellRender extends JPanel implements ListCellRenderer<Object>{

    private static Contact_Info cinfo;
    JLabel name;
    JLabel msg;

    public CustomContactCellRender() {

        setOpaque(true);
        setLayout(new BoxLayout(this , BoxLayout.Y_AXIS));

        JPanel overallPanel = new JPanel();
        overallPanel.setLayout(new BoxLayout(overallPanel , BoxLayout.X_AXIS));
        overallPanel.setPreferredSize(new Dimension(40,400));
        add(overallPanel);

        JPanel firstPanel = new JPanel();
        firstPanel.setPreferredSize(new Dimension(40,40));
        firstPanel.setLayout(new BorderLayout());
        overallPanel.add(firstPanel);

        JPanel statusPanel = new JPanel();
        statusPanel.setPreferredSize(new Dimension(37,37));
        statusPanel.setLayout(new BorderLayout());

        firstPanel.add(statusPanel , BorderLayout.CENTER);
        firstPanel.add(Box.createRigidArea(new Dimension(3,40)) , BorderLayout.LINE_START);
        firstPanel.add(Box.createRigidArea(new Dimension(3,40)) , BorderLayout.LINE_END);
        firstPanel.add(Box.createRigidArea(new Dimension(40,3)) , BorderLayout.PAGE_END);
        firstPanel.add(Box.createRigidArea(new Dimension(40,3)) , BorderLayout.PAGE_START);

        JPanel photoPanel = new JPanel();
        photoPanel.setPreferredSize(new Dimension(32,32));
        photoPanel.setLayout(null);
        statusPanel.add(photoPanel);

        JPanel secondPanel = new JPanel();
        secondPanel.setLayout(new BoxLayout(secondPanel , BoxLayout.Y_AXIS));
        overallPanel.add(secondPanel);

        secondPanel.add(Box.createRigidArea(new Dimension(3,this.getWidth())));

        name = new JLabel();
        name.setPreferredSize(new Dimension(100,15));
        secondPanel.add(name);

        secondPanel.add(Box.createRigidArea(new Dimension(4,this.getWidth())));

        msg = new JLabel();
        msg.setPreferredSize(new Dimension(this.getWidth(),15));
        secondPanel.add(msg);

        secondPanel.add(Box.createRigidArea(new Dimension(4,this.getWidth())));
    };

    @Override
    public Component getListCellRendererComponent(JList list, Object value,
            int index, boolean isSelected, boolean cellHasFocus) {

        cinfo = Contact_Info.getInstance();

        name.setText(cinfo.getFirst_name(1));

        return this;
    }

EDIT: Updated Code

Where is Cell’s design? in CustomContactCellRender() or in getListCellRendererComponent?

If anyone has a tip I also accept

EDIT 2

I think you’re right... how I would name and add to JList?

Answer 1

Lucas, making my comments a response as promised.

Yes you are on the right track. There is material about ListCellRender in the official Java tutorial. You can find the sample source code here (it customizes a JComboBox, but there is not much difference from practice).

About where to put each thing:

1. CustomContactCellRender() is the builder of redenderer, you can put everything fixed here; the layout of your dashboard, its components and everything else that is relevant.

2. getListCellRendererComponentis the method that will return the component for each item. Fine adjustments and display of model values should all be done in this method, because only in it you will have access to the list object (value), element position (index), etc..

On how to set the name

Always remember the separation between model and redenderer. What feeds the list with values is the ListModel (whether you started the combo with an array or Vector the java built a model anonymous who inherits from Abstractlistmodel for you).

Well, if you have one ListModel of objects of the type Contact, the values of Renderer should also deal with Contact (you can specify the type in the declaration: implements ListCellRenderer<Contact>).

Once that’s done the only thing redenderer should do is feed its component with the received values:

public Component getListCellRendererComponent(JList list, Contact value,
        int index, boolean isSelected, boolean cellHasFocus) {

    name.setText(value.getNome());
    msg.setText(value.getMensagem()); 

    return this;
}

Of course in a real application you should also have some visual indicative of focus and selection; for example, change the color of the background or draw a border):

if (isSelected) {
    setBackground(list.getSelectionBackground());
    setForeground(list.getSelectionForeground());
} else {
    setBackground(list.getBackground());
    setForeground(list.getForeground());
}

if (cellHasFocus) {
   setBorder(UIManager.getBorder("List.focusCellHighlightBorder"));
} else
   setBorder(new EmptyBorder(1, 1, 1, 1));
} 

To adjust this type of detail it is good to take a look at the source code of the class Defaultlistcellrenderer (This varies greatly depending on the JDK version).

The whole working together:

Contact[] myContacts = new Contact[] {
    new Contact("Hans Solo", "Do not call him Harrison Ford"),
    new Contact("Jabba the Hutt", "Not Pizza Hut")
};
JList<Contact> list = new JList<>(myContacts);
list.setCellRenderer(new CustomContactCellRender());