Instantiation problem

Question

Hi !
To clarify my problem, I have trimmed down the 4 files (here included) to keep just the essential.
When I try to compile the project, I have a �cannot resolve symbol� message for the drawingPanel and the currentObject objects referenced in the ToolbarPanel class.
The compiler does not seem to see these objects although they should be already instantiated at this point. All files are in the same directory so the classes should be seen without import statements.
I had the same problem a while ago and I solved it by using static members or inner classes. But here I cant do that (and it does not make sens to do so).
I must be missing something about how files relate to each other. I thought that dividing a project into custom Panel related files was a good idea �
Any clue someone ? Thanks !
JF
import java.awt.*;
import javax.swing.*;
public class MainWindow extends JFrame {
     public DrawingPanel drawingPanel;
     public ToolbarPanel toolbarPanel;
     public static void main( String args[] )
          MainWindow mainWindow = new MainWindow();
          mainWindow.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
     public MainWindow()
          super( "Testing application" );
          Container mainPanel = getContentPane();
          mainPanel.setLayout( new BorderLayout() );
          //     custom Jpanel
          drawingPanel = new DrawingPanel();
          mainPanel.add( drawingPanel, BorderLayout.CENTER );
          //     custom Jpanel
          toolbarPanel = new ToolbarPanel();                         
          mainPanel.add( toolbarPanel, BorderLayout.NORTH );
          setSize( 800,570 );
          setVisible( true );
}// class MainWindow*******************************************************************************
import javax.swing.*;
public class DrawingPanel extends JPanel {
     public MyObject currentObject;
     public int newVariable;
     public DrawingPanel()
          newVariable = 31;     // Default value
          createNewObject();
     public void createNewObject()
          currentObject = new MyObject( newVariable );
}// class DrawingPanel*******************************************************************************
import javax.swing.*;
import java.awt.event.*;
public class ToolbarPanel extends JPanel implements ActionListener {
     private JButton addButton;
     public ToolbarPanel()
          addButton = new JButton( "  Add  " );
          add( addButton );
          addButton.addActionListener(this);
     public void actionPerformed( ActionEvent ae )
          if (ae.getSource() == addButton)
               drawingPanel.newVariable = currentObject.variable ++;
               drawingPanel.createNewObject();
}// class ToolbarPanel*******************************************************************************
public class MyObject {
     public int variable;
     public MyObject( int variable )
          this.variable = variable;
}// class MyObject

Answer 1

but that they don't
need any instance or class qualification toidentify
them.In Java 1.5 you can accomplish this.
Sort of. You're just explicitly mentioning the
qualifier in one place, but it's not completely gone.So ?
Java has to know where to look for variables ... it can't just mysteriously find them.
I don't know if you'll find anything "official" that
settles it once and for all, but a quick google turned
up enough to convince me not to call 'em "global
variables."Well, they may not be global in the way other languages think of them (and like you do; i.e. must be referred to w/o prefix) but they are still "global", so it doesn't really matter, IMO.
Your sentence would be better off something like: "Java doesn't have c-style global variables.".
For example, the JLS won't tell you explicitly that
you can have a variable who's value is 10, but itcan
be accomplished.That's not really the same thing.You are saying that the JLS should explicitly state something as achievable, and if it doesn't you can't say it exists.
I say: "Java has variables which are equal to 10".
You say: "Where in the JLS does it say that?"
Similarly, I say: "Java has variables which can be global"
You say: "Where in the JLS ... ?"