Re: Problem getting the JPopupMenu from the Action it generates

From:

Knute Johnson <eternal@knutejohnson.com>

Newsgroups:

comp.lang.java.programmer

Date:

Wed, 13 Aug 2014 08:43:01 -0700

Message-ID:

<lsg11r$8te$1@dont-email.me>

On 8/13/2014 08:02, FredK wrote:

On Wednesday, August 13, 2014 12:37:10 AM UTC-7, Steven Simpson wrote:

On 13/08/14 01:39, Knute Johnson wrote:

I'm having a problem getting the JPopupMenu from an Action that is

generated by the JPopupMenu. The error is a ClassCastException and it

is saying that what is returned by ActionEvent.getSource() cannot be

cast to a JPopupMenu because it is a JPopupMenu$1. JPopupMenu$1 is an

anonymous class and shouldn't be returned by ActionEvent.getSource().

Why not? The JPopupMenu.add(Action) method creates a JMenuItem (of type

JPopupMenu$1), adds it to the menu, and returns it. If you click that

item, it will be the source.

In the end, I'm trying to get to the component that was right clicked

to pop up the menu.

Couldn't see anything, but why not pass popupMenu as a constructor

argument to someAction?

Better yet, pass the target component (in your case, tf) as an argument
to the someAction constructor.

Passing in the JComponent in this example works but not if the
JPopupMenu is going to be used on several components.

But Steven pointed me to the solution. I was thinking that the source
of the ActionEvent had to be the JPopupMenu but in fact it is the
JPopupMenu$1, that is really a JMenuItem, that is the source. From that
point it is easy to get the parent of the JMenuItem and then the
invoking JComponent that triggered the JPopupMenu.

I'm curious though, how did you figure out that the JPoupMenu$1 was the
JMenuItem?

Thanks again Steven.

knute...

C:\Users\Knute Johnson\com\knutejohnson\cookbook>java test
true

javax.swing.JPopupMenu[,0,0,99x26,invalid,layout=javax.swing.plaf.basic.DefaultM
enuLayout,alignmentX=0.0,alignmentY=0.0,border=javax.swing.plaf.metal.MetalBorde
rs$PopupMenuBorder@5fa6820,flags=264,maximumSize=,minimumSize=,preferredSize=,de
siredLocationX=73,desiredLocationY=39,label=,lightWeightPopupEnabled=true,margin
=,paintBorder=true]

javax.swing.JTextField[,0,0,124x20,layout=javax.swing.plaf.basic.BasicTextUI$Upd
ateHandler,alignmentX=0.0,alignmentY=0.0,border=javax.swing.plaf.BorderUIResourc
e$CompoundBorderUIResource@29854cdd,flags=296,maximumSize=,minimumSize=,preferre
dSize=,caretColor=sun.swing.PrintColorUIResource[r=51,g=51,b=51],disabledTextCol
or=javax.swing.plaf.ColorUIResource[r=184,g 7,b=229],editable=true,margin=java
x.swing.plaf.InsetsUIResource[top=0,left=0,bottom=0,right=0],selectedTextColor=s
un.swing.PrintColorUIResource[r=51,g=51,b=51],selectionColor=javax.swing.plaf.Co
lorUIResource[r=184,g 7,b=229],columns=0,columnWidth=0,command=,horizontalAlig
nment=LEADING]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test extends JFrame {
     final JPopupMenu popupMenu;

     public test() {
         setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

         popupMenu = new JPopupMenu();
         popupMenu.add(new someAction());

         JTextField tf = new JTextField("textField");
         tf.setComponentPopupMenu(popupMenu);
         add(tf,BorderLayout.CENTER);
         pack();
         setVisible(true);
     }

     public class someAction extends AbstractAction {
         public someAction() {
             putValue(NAME,"do something");
         }

         public void actionPerformed(ActionEvent ae) {
             JComponent c = (JComponent)ae.getSource();
             System.out.println(c instanceof JMenuItem);
             System.out.println();
             System.out.println(c.getParent());
             System.out.println();
             System.out.println(((JPopupMenu)c.getParent()).getInvoker());
         }
     }

     public static void main(String... args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 new test();
             }
         });
     }
}

--

Knute Johnson