GUI/Swing

Question

Hello,
I'm trying to get the hang of GUI and Swing. I post the code of the concerned class (and a screenshot), but I think reading the comments will suffice.
Short story: It works removing posts with the remove button, because then I am able to backtrack with .parent(). But with the popup menu, this won't work (I suspect it is a stupid method anyway) although the panel doesn't object when I "add" the popupmenu.
I suspect the code is a mess in other respects as well; I know OO in theory but have almost none experience, so be patient but feel free to give hints : )
Dump: http://s3.postimage.org/350d6da23/dump2.png
package itemframe;
import java.text.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class ItemPanel extends JPanel {
     private JPopupMenu popMenu = new JPopupMenu("Edit");
     private JLabel topic;
     private JLabel category;
     private JLabel description;
     private JLabel priority;
     private JLabel date;
     private class EventHandler implements ActionListener {
          public void actionPerformed(ActionEvent event) {
               String command = event.getActionCommand();
               ItemFrame origoFrame;
               ItemPanel origoPanel;
               if (event.getSource() instanceof JButton) {
                    JButton origoButton = (JButton)event.getSource();
                    origoPanel = (ItemPanel)origoButton.getParent().getParent().getParent();
                    origoFrame = (ItemFrame)origoButton.getTopLevelAncestor();
                    if (command.equals("Edit")) origoPanel.popMenu.show(origoButton, 5, 5);
                    else if (command.equals("Remove")) origoFrame.removeItem(origoPanel);
               else if (event.getSource() instanceof JMenuItem) {
                    JMenuItem origoMenuItem = (JMenuItem)event.getSource();
                    // HERE I don't succeed in getting origoPanel/Frame as above
                    // as I get null if I try the same method
                    if (command.equals("Remove")) ; origoFrame.removeItem(origoPanel);
                    else if (command.equals("Description")) {
                         String eventName = JOptionPane.showInputDialog(origoFrame, "Description:", "");
                         setDescription(eventName);
                         origoFrame.validate();
     public void setDescription(String description) {
          this.description.setText(description);
     public ItemPanel() {
          EventHandler eventHandler = new EventHandler();
          (popMenu.add("Description")).addActionListener(eventHandler);
          popMenu.add("Topic");
          popMenu.add("Category");
          popMenu.add("Date");
          popMenu.add("Priority");
          popMenu.addSeparator();
          java.net.URL imgURL = ItemPanel.class.getResource("removeSmall.png");
          ImageIcon removeIcon = new ImageIcon(imgURL);
          (popMenu.add(new JMenuItem("Remove", removeIcon))).addActionListener(eventHandler);
          add(popMenu);
          topic = new JLabel("Topic");
          category = new JLabel("Category");
          description = new JLabel("Description of event");
          priority = new JLabel("0");
          Date now = new Date();
          date = new JLabel(DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.MEDIUM).format(now));
          setBorder(new LineBorder(Color.lightGray, 1));
          imgURL = ItemPanel.class.getResource("edit.png");
          ImageIcon editIcon = new ImageIcon(imgURL);
          JButton editButton = new JButton("Edit", editIcon);
          JButton removeButton = new JButton("Remove");
          removeButton.addActionListener(eventHandler);
          editButton.addActionListener(eventHandler);
          BorderLayout innerBorder = new BorderLayout();
          innerBorder.setHgap(5);
          JPanel inner = new JPanel(innerBorder);
          GridLayout buttonsGrid = new GridLayout(2, 1);
          buttonsGrid.setVgap(5);
          JPanel data = new JPanel(new GridLayout(5, 1));
          data.add(topic);
          data.add(date);
          data.add(category);
          data.add(priority);
          data.add(description);
          JPanel buttons = new JPanel(buttonsGrid);
          buttons.add(editButton);
          buttons.add(removeButton);
          inner.add(data, BorderLayout.WEST);
          inner.add(buttons, BorderLayout.EAST);
          add(inner);
}Edited by: 831834 on Jan 27, 2011 10:56 AM

Answer 1

Why all of that complicated getParent() anyway? EventHandler is an inner class, so you have full access to the variables of the outer class. ItemPanel.this gives you access to the ItemPanel that encloses the EventHandler instance. +origoPanel is always the same as ItemPanel.this+ . If getTopLevelAncestor is properly giving you the frame, then the following should work.
if (event.getSource() instanceof JButton) {
   if (command.equals("Edit")) {
     JButton origoButton = (JButton)event.getSource();
     popMenu.show(origoButton, 5, 5);
   else if (command.equals("Remove")) {
      // Might also be able to use ItemPanel.this.getParent() instead of getTopLevelAncestor()?
      // I don't know your full hierarchy.
      ((ItemFrame)ItemPanel.this.getTopLevelAncestor()).removeItem(ItemPanel.this);
else if (event.getSource() instanceof JMenuItem) {
   if (command.equals("Description")) {
      String eventName = JOptionPane.showInputDialog(origoFrame, "Description:", "");
      setDescription(eventName);
      ((ItemFrame)ItemPanel.this.getTopLevelListener()).validate();
}If Remove should do the same regardless of whether it's from the JButton or from the JMenuItem, then you don't need to repeat that "if" check twice--just do the check for "Remove" outside the loop. If you are using action commands, you probably don't need to test the type of the source (JButton vs. JMenuItem), anyway, unless you have the same action commands on both types that should do different things based on type (if they should do different things, it's probably a bad design). Then you only need the source if you actually need to act on the source. In your code, I don't think you need to know that origoButton is a JButton--just a JComponent or Component or something (whatever the first parameter of JPopupMenu.show is).