Re: How to get reference for JFrame

From:
"Kalessin" <kalessin@teranews.com>
Newsgroups:
comp.lang.java.gui
Date:
Sat, 11 Apr 2009 17:08:48 +0800
Message-ID:
<G6ZDl.40554$0%2.24671@newsfe22.iad>
I Personally prefer SwingUtilities.getRoot(Component)
so for a JMenuItem you would use;

++SNIP++
import java.awt.Component;
import java.awt.Desktop.Action;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Owner
 */

public class MyMenu extends JMenuBar{

    public static void main(String args[]) {
        JFrame frame = new JFrame();
        MyMenu menu = new MyMenu();
        frame.setJMenuBar(menu);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400,400);
        frame.setVisible(true);
    }

AbstractAction show_dialog_box = new AbstractAction("Show Dialog Box") {
public void actionPerformed(ActionEvent e) {
       JComponent source = (JComponent)e.getSource();
       Component root = SwingUtilities.getRoot(source);
       JFrame frame = (JFrame)root;
       // Substitute in JOptionPane, JDialog, or JFileDialog as needed
       String name = JOptionPane.showInputDialog(root, "Please Enter Your
Name","Enter Name",JOptionPane.OK_CANCEL_OPTION);
       if( name == null ) {
           System.out.println("You Pressed Cancel!");
           return;}
       System.out.println("Your Name Is "+name);
       }
};
JMenuItem menu = new JMenuItem(show_dialog_box);

public MyMenu() {
    add(menu);
}
}
++SNIP++

you can if you wanted to, place complex objects on your JFrame object, and
use casting to cast it to your special JFrame class
(ie - Instead of
JFrame frame = (JFrame)root;
you would do
MyJFrame frame = (MyJFrame)root;
then
frame.someSpecialMethodIMade();
which would enable you to access all the methods on your own JFrame class,
rather than treating it like a standard JFrame)
, but i think it looks really messy :( i'm not sure what other people think
about how they pass references from one class to another..
i prefer to create a specific class for the express purpose of holding all
my model classes, and passing a reference to into the constructor of each of
my view classes... but i digress... for simple learning things it's probably
not required of you to separate your code like that.
Best Regards
   James Gardner

SwingUtilties.getRoot(
"Daniel Pitts" <newsgroup.spamfilter@virtualinfinity.net> wrote in message
news:49de18db$0$3632$7836cce5@newsrazor.net...

Coolm@x wrote:

Hello,
I want to ask for an example. I want to run JDialog from JMenuItem. I
have JFrame in one file and JDialog in another. As far as I know I must
pass frame-parent as argument to JDialog. Examples which I found were
similar to:

JFrame frame = new JFrame();
JDialog dialog = new JDialog(frame (...)

Code is in one class, so there is no problem. I don't know how to pass
argument in this:

Main.java:
(...)
public static void main(String[] args) {
Main ste = new Main();
ste.setVisible(true); }

public Main() {
super();
initialize(); }

private void initialize() {
this.setSize(700, 500);
this.setJMenuBar(pasekMenu());
this.setContentPane(oknoGlowne()); }
(...)
private JMenuItem getHelp() {
if (HelpAbout == null) {
HelpAbout = new JMenuItem();
HelpAbout.setText("About");

HelpAbout.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
???
}});
}
return HelpAbout; }
(...)

JDabout.java:

public JDabout(Frame owner) {
super(owner);
initialize();
}

Is there any method to get jFrame parent? Also, is this code correct:
JDabout about = new JDabout(?);


the JFrame parameter is an optional parameter, meaning you can do:
new JDialog((JFrame)null);

--
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