How do I press, add, NOT RELEASE and drag?

Question

When I press the mouse-button in my panel, my program will add a component under the mousepointer. I would like to start dragging this component, without first releasing the button and then grabbing the component by pressing a second time. Can it be done?
This code does not do it:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class AddNDragTest extends JFrame {
    public AddNDragTest() {
        super("Click to add a box");
        setPreferredSize(new Dimension(700,500));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());
        pane = new JPanel();
        pane.setLayout(null);
        // Add a box under the mousepointer when mouse is pressed in 'pane'
        pane.addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent me) {
                Box box = new Box();
                box.addMouseListener(boxListener);
                box.addMouseMotionListener(boxListener);
                // Center the box on the mousepointer
                box.setLocation(me.getX() - box.getWidth() / 2,me.getY() - box.getHeight() / 2);
//                box.dragging = true;
                pane.add(box);
                repaint();
        add(pane);
    JPanel pane;
    MouseAdapter boxListener = new MouseAdapter() {
        public void mousePressed(MouseEvent me) {
            Box box = (Box) ( me.getSource() );
            box.mx0 = me.getX();
            box.my0 = me.getY();
//            box.dragging = true;
//        public void mouseReleased(MouseEvent me) {
//            Box box = (Box) ( me.getSource() );
//            box.dragging = false;
//        public void mouseMoved(MouseEvent me) {
//            Box box = (Box) ( me.getSource() );
//            if (box.dragging)
//                box.setLocation(box.getX() + me.getX() - box.mx0,box.getY() + me.getY() - box.my0);
        public void mouseDragged(MouseEvent me) {
            Box box = (Box) ( me.getSource() );
            box.setLocation(box.getX() + me.getX() - box.mx0,box.getY() + me.getY() - box.my0);
    class Box extends JPanel {
        public Box() {
            super();
            setSize(50,50);
            setBackground(Color.YELLOW);
            setBorder(BorderFactory.createLineBorder(Color.GREEN));
            setOpaque(true);
        // Store the location where the box was pressed upon to pretend
        // that it is beeing held at that point
        int mx0, my0;
        // Attempting to drag the box by listening for mouseMoved don't work
//        boolean dragging;
    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                //Create and set up the window
                AddNDragTest test = new AddNDragTest();
                //Center and display the window..
                test.pack();
                Dimension scr = Toolkit.getDefaultToolkit().getScreenSize();
                Dimension siz = test.getSize();
                test.setLocation(( scr.width - siz.width ) / 2,( scr.height - siz.height ) / 2);
                test.setVisible(true);
}No hurry here, this is a hobby.

Answer 1

Well, in addition to adding the MouseListener to the "pane" you need to add a MouseMotionListener to handle the drag events as they will still be generated on the "pane", not the Box. The drag events would simply set the location of the newly added Box.
By the way don't use "Box" for the class name, there is already a Swing class using that name so it can be confusing.