How can I know when an instance variable raise a event in java?

Question

i have created a class to create the UserInterface of my program, my program has an instance of that UserInterface.

The UserIterface class has some listeners, my problem now is that i need to know from my program main class when my instance variable used to create the user interface raises events as for example tree valueChanged.

This is my userInterface class:

    import java.awt.EventQueue;
    import javax.swing.JFileChooser;
    import javax.swing.JFrame;
    import javax.swing.JMenuBar;
    import javax.swing.JMenuItem;
    import javax.swing.JToolBar;
    import java.awt.BorderLayout;
    import javax.swing.JButton;
    import javax.swing.JTree;
    import javax.swing.JSplitPane;
    import javax.swing.JPanel;
    import javax.swing.event.TreeSelectionEvent;
    import javax.swing.event.TreeSelectionListener;
    import javax.swing.filechooser.FileNameExtensionFilter;
    import javax.swing.tree.DefaultTreeModel;
    import javax.swing.tree.DefaultMutableTreeNode;
    import javax.swing.tree.TreeSelectionModel;

    import org.eclipse.swt.widgets.Tree;

    import java.awt.Dimension;
    import java.awt.event.ActionListener;
    import java.awt.event.ActionEvent;
    import java.io.FileNotFoundException;
    import java.io.IOException;


    public class UserInterfaceWindow implements TreeSelectionListener{

        public JFrame frame;
        public JTree tree;
        public JPanel panel;
        public JFileChooser fileChooser;
        public IffFile iffFile;
        public CustomRanAccFile inputRandAccFile;
        /**
         * Create the application.
         */
        public UserInterfaceWindow() {
            initialize();
            frame.setVisible(true);
        }



        /**
         * Initialize the contents of the frame.
         */
        private void initialize() {
            frame = new JFrame();
            frame.setBounds(100, 100, 758, 549);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            JToolBar toolBar = new JToolBar();
            frame.getContentPane().add(toolBar, BorderLayout.NORTH);

            JButton btnOpenFile = new JButton("Open File");
            btnOpenFile.addActionListener(new OpenButtonClick());
            toolBar.add(btnOpenFile);

            JButton button = new JButton("New button");
            toolBar.add(button);

            JSplitPane splitPane = new JSplitPane();
            splitPane.setMinimumSize(new Dimension(300, 25));
            frame.getContentPane().add(splitPane, BorderLayout.CENTER);

            tree = new JTree();
            tree.setModel(new DefaultTreeModel(
                new DefaultMutableTreeNode("File") {
                    /**
                     * 
                     */
                    private static final long serialVersionUID = 1L;

                    {
                    }
                }
            ));
            tree.setMinimumSize(new Dimension(200, 0));
            tree.setMaximumSize(new Dimension(200, 64));
            tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
            tree.addTreeSelectionListener(this);
            splitPane.setLeftComponent(tree);

            panel = new JPanel();
            splitPane.setRightComponent(panel);
        }



        public class OpenButtonClick implements ActionListener{

            @Override
            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(fileChooser==null)
                    setUpFileChooser();


                if(fileChooser.showOpenDialog(frame)==JFileChooser.APPROVE_OPTION){

                    try {
                        if(inputRandAccFile!=null)
                            inputRandAccFile.close();
                        inputRandAccFile= new CustomRanAccFile(fileChooser.getSelectedFile(),"rw");
                        iffFile=IffUtils.createIffFileInfo(inputRandAccFile);
                        IffUtils.obtainSubFileList2K14(iffFile, inputRandAccFile);
                        UserInterfaceWindow.this.setTreeElements(iffFile,UserInterfaceWindow.this.tree);


                    } catch (FileNotFoundException e1) {
                        // TODO Auto-generated catch block
                        e1.printStackTrace();
                    } catch (IOException e1) {
                        // TODO Auto-generated catch block
                        e1.printStackTrace();
                    }



                }
            }
        }



        public void setTreeElements(IffFile iffFile, JTree tree){


            DefaultMutableTreeNode iffNode= new DefaultMutableTreeNode(iffFile);
            DefaultTreeModel model= new DefaultTreeModel(iffNode, true);


            for(IffBaseSubFile subFile: iffFile.getSubFileList()){

                iffNode.add(new DefaultMutableTreeNode(subFile,false));
            }

            tree.setModel(model);
        }


        public void setUpFileChooser(){
            fileChooser= new JFileChooser();
            fileChooser.setDialogTitle("Select File");
            FileNameExtensionFilter iffcdfFilter= new FileNameExtensionFilter("IFF/CDF Files","iff","CDF Files","cdf");
            fileChooser.addChoosableFileFilter(iffcdfFilter);
            fileChooser.setAcceptAllFileFilterUsed(false);


    fileChooser.setFileFilter(iffcdfFilter);
    }


    @Override
    public void valueChanged(TreeSelectionEvent e) {
        // TODO Auto-generated method stub

    }



}

And this is Myprogram:

    public class MyMain {
UserInterfaceWindow uiWindow;
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        MyMain myMain= new MyMain();
        myMain.uiWindow= new UserInterfaceWindow();
    }

}

Answer 1

The event TreeSelectionEvent will be triggered when the user clicks on a node of the tree.