Selection of among multiple JInternalFrames in a container(JPanel)

Question

I have some set of JInternalFrame in a Jpanel. and the JPanel is gridlayout. I need to set only one JInternalFrame to be selected in the container (JPanel). I created the JInternalFrame instance dynamically and add to the panel. I still have the list of JInternalFrame but how to make only one to set selected.

Answer 1

As suggested in How to Use Internal Frames, "Usually, you add internal frames to a desktop pane." This allows you to use activateFrame() to indicate that a frame has focus. In this example, a javax.swing.Action is used to select frames from a menu via setSelected(). Additional discussion may be found in this Q&A.

Addendum: If you want to use a JPanel, perhaps to get a nice GridLayout, one aproach is to use an InternalFrameListener as shown below.

import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.beans.PropertyVetoException;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.event.InternalFrameAdapter;
import javax.swing.event.InternalFrameEvent;

/** @see https://stackoverflow.com/questions/8389640 */
public class InternalGrid extends JPanel {

    private final List<MyFrame> list = new ArrayList<MyFrame>();

    public InternalGrid() {
        super(new GridLayout(2, 2));
        for (int i = 0; i < 4; i++) {
            MyFrame f = new MyFrame("Frame", i);
            list.add(f);
            this.add(f);
        }
    }

    private void display() {
        JFrame f = new JFrame("InternalGrid");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(this);
        f.pack();
        f.setSize(320, 240);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new InternalGrid().display();
            }
        });
    }

    class MyFrame extends JInternalFrame {

        MyFrame(String name, int i) {
            super(name + String.valueOf(i), true, true, true, false);
            this.pack();
            this.setVisible(true);
            this.setLayout(new FlowLayout());
            this.add(new JLabel("Hi, I'm " + this.getTitle()));
            this.addInternalFrameListener(new InternalFrameAdapter() {

                @Override
                public void internalFrameActivated(InternalFrameEvent e) {
                    for (MyFrame f : list) {
                        if (f != MyFrame.this) {
                            try {
                                f.setSelected(false);
                            } catch (PropertyVetoException ex) {
                                System.out.println(ex);
                            }
                        }
                    }
                }
            });
        }
    }
}