Show popup menu on a jlist

Question

I have problem with popup menu. That that I want is that when the user click the right mouse button on a jlist a popup menu appear. I have created a class where I create the popup menu, a class that extend mouselistener, and another class where I add mouse listener to the jlist. In the class that extend mouselistener I call the class of the popup menu and i show it. The problem is that the popup menu doesn't appear.

package mouseListener;

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

import javax.swing.*;

import view.___poupupmenu___;

public class Add_popupmenu_categoria implements MouseListener 
{
   JList <String> l = new JList <String> ();

    public Add_popupmenu_categoria (JList <String> l)
{
    this.l = l;
}

public void mouseClicked(MouseEvent evt)
{
    System.out.println("clicked");

    if (evt.isPopupTrigger()) 
    {
        System.out.println("enter in clicked");

        ___poupupmenu___ p = new ___poupupmenu___();

        l.setSelectedIndex(l.locationToIndex(evt.getPoint()));
        System.out.println(evt.getComponent());
        l.setComponentPopupMenu(p.menu_categoria);
        p.menu_categoria.show(evt.getComponent(), evt.getX(), evt.getY());

    } 
}          


public void mouseEntered(MouseEvent e)
{

}

public void mouseExited(MouseEvent e)
{

}

public void mousePressed(MouseEvent evt)
{
    System.out.println("pressed");

    if (evt.isPopupTrigger()) 
    {
        System.out.println("enter in pressed");

        ___poupupmenu___ p = new ___poupupmenu___();

        l.setSelectedIndex(l.locationToIndex(evt.getPoint()));
        System.out.println(evt.getComponent());
        l.setComponentPopupMenu(p.menu_categoria);
        p.menu_categoria.show(evt.getComponent(), evt.getX(), evt.getY());

    } 
}

public void mouseReleased(MouseEvent evt)
{

    System.out.println("released");

    if (evt.isPopupTrigger()) 
    {
        System.out.println("enter in released");

        ___poupupmenu___ p = new ___poupupmenu___();

        l.setSelectedIndex(l.locationToIndex(evt.getPoint()));
        System.out.println(evt.getComponent());
        l.setComponentPopupMenu(p.menu_categoria);
        p.menu_categoria.show(evt.getComponent(), evt.getX(), evt.getY());


    } 
}
}



package view;

import javax.swing.*;

import java.awt.*;

public class ___poupupmenu___ {

public JPopupMenu menu_categoria = new JPopupMenu();
public JPopupMenu menu_scuola = new JPopupMenu();
public JPopupMenu menu_maschile_femminile = new JPopupMenu();
public JPopupMenu menu_dirigenti_allenatori = new JPopupMenu();
public JPopupMenu menu_img_profilo = new JPopupMenu();

JMenuItem menu_elimina = new JMenuItem("Elimina");
JMenuItem menu_modifica = new JMenuItem("Modifica");
JMenuItem menu_apri = new JMenuItem("Apri...");    
JMenuItem menu_pagamento = new JMenuItem("Visualizza pagamenti");
JMenuItem menu_genitore = new JMenuItem("Visualizza genitore");
JMenuItem menu_visita_medica = new JMenuItem("Visualizza scadenza visita medica");

  public ___poupupmenu___ ()
  {
       menu_elimina.setFont(new Font("Segoe UI", 1, 15)); 
       menu_modifica.setFont(new Font("Segoe UI", 1, 15)); 
       menu_apri.setFont(new Font("Segoe UI", 1, 15)); 
       menu_pagamento.setFont(new Font("Segoe UI", 1, 15));  
       menu_genitore.setFont(new Font("Segoe UI", 1, 15)); 

       menu_categoria.add(menu_modifica);
       menu_categoria.add(menu_elimina);

       menu_scuola.add(menu_apri);
       menu_scuola.add(menu_visita_medica);
       menu_scuola.add(menu_genitore);
       menu_scuola.add(menu_pagamento);
       menu_scuola.add(menu_modifica);
       menu_scuola.add(menu_pagamento);

       menu_maschile_femminile.add(menu_apri);
       menu_maschile_femminile.add(menu_visita_medica);
       menu_maschile_femminile.add(menu_modifica);
       menu_maschile_femminile.add(menu_elimina);

       menu_dirigenti_allenatori.add(menu_apri);
       menu_dirigenti_allenatori.add(menu_modifica);
       menu_dirigenti_allenatori.add(menu_elimina);

   }

}


package controller;

import javax.swing.*;

import mouseListener.Add_popupmenu_categoria;

public class CategoriaController 
{

   public void add_popupmenu_Categoria (JList <String> l)
   {
      Add_popupmenu_categoria apmc = new Add_popupmenu_categoria (l);
      l.addMouseListener(apmc);
   }
}

When I click what I get is:

pressed released enter in released javax.swing.JList[,0,0,897x797,alignmentX=0.0,alignmentY=0.0,border=,flags=50331944,maximumSize=,minimumSize=,preferredSize=,fixedCellHeight=-1,fixedCellWidth=-1,horizontalScrollIncrement=-1,selectionBackground=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],selectionForeground=sun.swing.PrintColorUIResource[r=51,g=51,b=51],visibleRowCount=8,layoutOrientation=0] clicked

Someone can help me?

Answer 1

Edit: The simplest way is to just use the setComponentPopupMenu Method of the JList:

JPopupMenu popup = new JPopupMenu();
popup.add(new JMenuItem("Hello World"));

JList<String> jList = new JList<String>();
jList.setComponentPopupMenu(popup);

setComponentPopupMenu(popup) appends the popup to the component. It will show automatically if you right-click the component. No MouseListener needed.

Another easy way to implement Popup-Menus for swing components is to override the getComponentPopupMenu() Method of JComponent. For you the solution would look something like this:

public class MyJListWithPopupMenu extends JList {
    //...
    @Override
    public JPopupMenu getComponentPopupMenu() {
        // create your PopupMenu
        return myJPopupMenu;
    }
    //...
}

When you then use the MyJListWithPopupMenu instead of a regular JList, the popup wil show in the right place when you right-click on it.