Re: Drag two images with a mouse anywhere in the frame

Hi Daniele and John,
A big "THANKS" for your replies.
The program below takes 3 images
allows for showing them in random order
at random locations. The user then uses the mouse to
move the images to reorder. It is a work in progress.
I have not studied the entire list of your
recommendations but eventually hope to do so.

I appreciate your responses very much.
bH

/* original: http://www.thatsjava.com/java-essentials/49032/
  *
  * Version2: 22 March 2011:
  * Three XX.png images stored in folder named "images"
  * The program takes the images puts them in random order
  * at random locations. The user then uses the mouse to
  * move the images to reorder. bH
  */
import java.awt.EventQueue;
import java.awt.Container;
import java.awt.Component;
import java.awt.GridLayout;

import java.awt.event. MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseEvent;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing. JLayeredPane;
import javax.swing.ImageIcon;
import javax.swing.JLabel;

public class LabelDragAndDropVer2 extends JFrame implements
     MouseListener, MouseMotionListener
{
     JLayeredPane layeredPane;
     Component dragComponent;
     int xAdjustment;
     int yAdjustment;
     private String strNumber[] = new String [3];
     private int number = 0 ;

     private Random wheel = new Random();
     int high= 60;
     int low = 20;
     int numPictures = 3;

     // two arrays stores x,y values
     int[] xPoints = new int[numPictures];
     int[] yPoints = new int[numPictures];

     public LabelDragAndDropVer2() {
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         init();
         setVisible(true);
     }

     public void init() {
     // Use a Layered Pane for this this application
         layeredPane = new JLayeredPane();
         layeredPane.setLayout( null );
         layeredPane.addMouseListener( this );
         layeredPane.addMouseMotionListener( this );
         getContentPane().add(layeredPane);

         // ordering the location of picture random
         for (int i= 0;i<numPictures; i++){
             int m = wheel.nextInt(high - low + 1 ) + low;
             xPoints[i]= m;
             int n = wheel.nextInt(high - low + 1 ) + low;
             yPoints[i]= n;
             System.out.println(i+ " "+ m + " ," + n);
         }
         System.out.println("");

         for(int i = 0; i<3; i++){
             strNumber[i] = Integer.toString(i);
             number = Integer.parseInt(strNumber[i]);
             System.out.println(number);
         }
         // ordering the images randomly
         List<String> inputList = Arrays.asList(strNumber);
         Collections.shuffle(inputList);

         for (int i= 0;i<3; i++){
             number = Integer.parseInt(strNumber[i]);
             ImageIcon julia = new ImageIcon("images/MH"+
                                             number + ".png");
             JLabel label = new JLabel(julia);
             label.setLocation(xPoints[i], yPoints[i]);
             label.setSize( label.getPreferredSize() );
             layeredPane.add(label);
         }

         Container contentPane= getContentPane();
         contentPane.setLayout(new GridLayout(1,2) );
         setSize(600,600);// frame size
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     }
     /*
      ** Determine if we clicked on a moveable component
      */
     public void mousePressed(MouseEvent e)
     {
         dragComponent = null;
         Component c = layeredPane.findComponentAt(e.getX(),
                                                   e.getY());
         if (c instanceof JLayeredPane) return;
         dragComponent = c;
         xAdjustment = dragComponent.getLocation().x - e.getX();
         yAdjustment = dragComponent.getLocation().y - e.getY();
         dragComponent.setLocation(e.getX() + xAdjustment,
                                   e.getY() + yAdjustment);
         layeredPane.moveToFront(dragComponent);
     }
     /*
      ** Move the component around the panel
      */
     public void mouseDragged(MouseEvent me)
     {
         if (dragComponent == null) return;
         dragComponent.setLocation(me.getX() + xAdjustment,
                                   me.getY() + yAdjustment);
     }
     /*
      ** Deselect the component
      */
     public void mouseReleased(MouseEvent e)
     {
         dragComponent = null;
     }
     public void mouseClicked(MouseEvent e) {}
     public void mouseMoved(MouseEvent e) {}
     public void mouseEntered(MouseEvent e) {}
     public void mouseExited(MouseEvent e) {}

     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             @Override
             public void run() {
                 new LabelDragAndDropVer2();
             }
         });
     }
}