JCombobox with JMenuBar (as drop down menu)

Question

Hello, i'm trying to make a new component (as generic as possible) to display a tree structure in a combo-like style.
So i finally choose a JTextfield to display the current item + a JMenuBar with Menu and MenuItem generated from a TreeModel (i'm not sure this is the better choice to make, but tha's not my present problem).
2 questions :
1) am I reinventing the wheel ???
2) i've got a problem of pack when displaying the compent and i don't find where.
Thanks. Cyril.
So, the code... two main classes : TreeComboBox + ArrowMenu
the TreeComboBox :
package fr.emanation.util.gui.treeComboBox;
import javax.swing.*;
import javax.swing.tree.TreeModel;
import java.awt.*;
import java.awt.event.FocusListener;
public class TreeComboBox<TNode> extends JPanel
  private TNode theSelectedNode;
  private ArrowMenuBar theMenuBar;
  private JTextField theTextField;
  private int theCompactWidth;
  public TreeComboBox(TreeModel aTreeModel)
    new BorderLayout(0, 0);
    theTextField = new JTextField();
    theTextField.setEditable(true);
    theTextField.setBackground(Color.white);
    setFocusable(false);
    add(theTextField, BorderLayout.CENTER);
    MyArrowMenuInvoker anInvoker = new MyArrowMenuInvoker();
    theMenuBar = new ArrowMenuBar<TNode>(anInvoker, aTreeModel);
    JPanel menuBarPanel = new JPanel(new BorderLayout(0, 0));
    menuBarPanel.add(theMenuBar, BorderLayout.CENTER);
    add(menuBarPanel, BorderLayout.EAST);
  public TNode getNode()
    return (TNode) theSelectedNode;
  public void setSelectedNode(TNode aNode)
    theSelectedNode = aNode;
    theTextField.setText(aNode.toString());
  public TreeModel getModel()
    return theMenuBar.getModel();
  public JComponent[] getFocusableComponents()
    return new JComponent[]{theTextField, theMenuBar};
  //-- JComponent overriden methods
  public Dimension getMinimumSize()
    final Dimension minSize = super.getMinimumSize();
    minSize.width = theCompactWidth;
    return minSize;
  public void setCompactWidth(final int aCompactWidth)
    theCompactWidth = aCompactWidth;
  public void setPreferredSize(Dimension aSize)
    super.setPreferredSize(aSize);
    if (theTextField != null)
      theTextField.setPreferredSize(aSize);
  public void setForeground(Color fg)
    super.setForeground(fg);
    if (theMenuBar != null)
      for (int index = 0; index < theMenuBar.getComponentCount(); index++)
        theMenuBar.getComponents()[index].setForeground(fg);
    if (theTextField != null)
      theTextField.setForeground(fg);
  public void setBackground(Color bg)
    super.setBackground(bg);
    if (theMenuBar != null)
      for (int index = 0; index < theMenuBar.getComponentCount(); index++)
        theMenuBar.getComponents()[index].setBackground(bg);
    if (theTextField != null)
      theTextField.setBackground(bg);
  public void setFont(Font aFont)
    super.setFont(aFont);
    if (theMenuBar != null)
      theMenuBar.setFont(aFont);
    if (theTextField != null)
      theTextField.setFont(aFont);
  public void setToolTipText(String aToolTip)
    super.setToolTipText(aToolTip);
    if (theTextField != null)
      theTextField.setToolTipText(aToolTip);
  public void setEnabled(final boolean bEnabled)
    super.setEnabled(bEnabled);
    if (theTextField != null) return;
      theTextField.setEnabled(bEnabled);
      if (bEnabled)
        theTextField.setBackground(Color.WHITE);
      else
        JLabel tmpLabel = new JLabel();
        tmpLabel.setEnabled(false);
        theTextField.setBackground(tmpLabel.getBackground());
    if (theMenuBar != null)
      theMenuBar.setEnabled(bEnabled);
  public synchronized void addFocusListener(FocusListener l)
    super.addFocusListener(l);
    if (theMenuBar != null)
      theMenuBar.addFocusListener(l);
    if (theTextField != null)
      theTextField.addFocusListener(l);
  public synchronized void removeFocusListener(FocusListener l)
    super.removeFocusListener(l);
    if (theMenuBar != null)
      theMenuBar.removeFocusListener(l);
    if (theTextField != null)
      theTextField.removeFocusListener(l);
  public boolean isFocusOwner()
    if (theMenuBar == null || theTextField == null) return super.isFocusOwner();
    boolean bM = (theMenuBar == null) && theMenuBar.isFocusOwner();
    boolean bT = (theTextField == null) && theTextField.isFocusOwner();
    return (bM || bT);
  //-- inner classes
  private class MyArrowMenuInvoker implements IArrowMenuInvoker<TNode>
    public Component getComponent()
      return theTextField;
    public void setNode(TNode aNode)
      setSelectedNode(aNode);
}the ArrowMenuBar :
package fr.emanation.util.gui.treeComboBox;
import javax.swing.*;
import javax.swing.border.EtchedBorder;
import javax.swing.plaf.UIResource;
import javax.swing.tree.TreeModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class ArrowMenuBar<TNode> extends JMenuBar
  private NodeMenu theMenu;
  private TreeModel theModel;
  private IArrowMenuInvoker<TNode> theInvoker;
  public ArrowMenuBar(IArrowMenuInvoker<TNode> anInvoker, TreeModel aModel)
    super();
    theModel = aModel;
    theInvoker = anInvoker;
    TNode root = (TNode) theModel.getRoot();
    if (!theModel.isLeaf(root))
      theMenu = new ArrowMenu(root);
      theMenu.setBackground(new JPanel().getBackground());
    MenuItemListener listener = new MenuItemListener();
    setListener(theMenu, listener);
    add(theMenu);
  private void setListener(JMenuItem anItem, ActionListener aListener)
    if (anItem instanceof JMenu)
      JMenu menu = (JMenu) anItem;
      int n = menu.getItemCount();
      for (int index = 0; index < n; index++)
        setListener(menu.getItem(index), aListener);
    else if (anItem != null)
      // null means separator
      anItem.addActionListener(aListener);
  public TreeModel getModel()
    return theModel;
  public Action getLaunchArrowMenuBarAction()
    return new LaunchArrowMenuBarAction();
  //-- overrides JComponent
  public Dimension getPreferredSize()
    return theMenu.getPreferredSize();
  private Dimension getItemSize(JMenu aMenu)
    Dimension dimension = new Dimension(0, 0);
    int n = aMenu.getItemCount();
    for (int index = 0; index < n; index++)
      Dimension itemD;
      JMenuItem item = aMenu.getItem(index);
      if (item instanceof JMenu)
        itemD = getItemSize((JMenu) item);
      else if (item != null)
        itemD = item.getPreferredSize();
      else
        itemD = new Dimension(0, 0); // separator
      dimension.width = Math.max(dimension.width, itemD.width);
      dimension.height = Math.max(dimension.height, itemD.height);
    return dimension;
  //--- inner classes
  private class LaunchArrowMenuBarAction extends AbstractAction
    public LaunchArrowMenuBarAction()
      super("...");
    public void actionPerformed(ActionEvent e)
      if (e.getActionCommand() == "Launch")
        System.out.println("Launch");
  private class MenuItemListener implements ActionListener
    public void actionPerformed(ActionEvent anEvent)
      NodeMenuItem item = (NodeMenuItem) anEvent.getSource();
      theInvoker.setNode(item.getNode());
      theMenu.requestFocus();
  private class NodeMenu extends JMenu
    private TNode theNode;
    public NodeMenu(TNode aNode)
      this(aNode.toString(), aNode);
    public NodeMenu(String theText, TNode aNode)
      super(theText);
      theNode = aNode;
      add(new NodeMenuItem("[.]", aNode));
      for (int index = 0; index < theModel.getChildCount(aNode); index++)
        TNode childNode = (TNode) theModel.getChild(aNode, index);
        if (theModel.isLeaf(childNode))
          add(new NodeMenuItem(childNode));
        else
          add(new NodeMenu(childNode));
    public void setNode(TNode aNode)
      theNode = aNode;
    public TNode getNode()
      return theNode;
  private class NodeMenuItem extends JMenuItem
    private TNode theNode;
    public NodeMenuItem(TNode aNode)
      super(aNode.toString());
      theNode = aNode;
    public NodeMenuItem(String aText, TNode aNode)
      super(aText);
      theNode = aNode;
    public TNode getNode()
      return theNode;
  private class ArrowMenu extends NodeMenu
//    private ArrowIcon theIconRenderer;
    private Color shadow = UIManager.getColor("controlShadow");
    private Color darkShadow = UIManager.getColor("controlDkShadow");
    private Color highlight = UIManager.getColor("controlLtHighlight");
    public ArrowMenu(TNode aNode)
      super("", aNode);
//      theIconRenderer = new ArrowIcon(SwingConstants.SOUTH, true);
      setBorder(new EtchedBorder());
//      setIcon(new BlankIcon(null, 11));
      setHorizontalTextPosition(JButton.LEFT);
      setFocusPainted(true);
    public void paint(Graphics g)
      Color origColor;
      boolean isEnabled;
      int w, h, size;
      w = getSize().width;
      h = getSize().height;
      origColor = g.getColor();
      isEnabled = isEnabled();
      g.setColor(getBackground());
      g.fillRect(1, 1, w - 2, h - 2);
      /// Draw the proper Border
      if (getBorder() != null && !(getBorder() instanceof UIResource))
        paintBorder(g);
      else
        // Using the background color set above
        g.drawLine(0, 0, 0, h - 1);
        g.drawLine(1, 0, w - 2, 0);
        g.setColor(highlight);  // inner 3D border
        g.drawLine(1, 1, 1, h - 3);
        g.drawLine(2, 1, w - 3, 1);
        g.setColor(shadow);     // inner 3D border
        g.drawLine(1, h - 2, w - 2, h - 2);
        g.drawLine(w - 2, 1, w - 2, h - 3);
        g.setColor(darkShadow);   // black drop shadow  __|
        g.drawLine(0, h - 1, w - 1, h - 1);
        g.drawLine(w - 1, h - 1, w - 1, 0);
      // If there's no room to draw arrow, bail
      if (h < 5 || w < 5)
        g.setColor(origColor);
        return;
      // Draw the arrow
      size = Math.min((h - 4) / 3, (w - 4) / 3);
      size = Math.max(size, 2);
      paintTriangle(g, (w - size) / 2, (h - size) / 2,
              size, SwingConstants.SOUTH, isEnabled);
      // Reset the Graphics back to it's original settings
      g.setColor(origColor);
    public Dimension getPreferredSize()
      return new Dimension(16, 16);
    public Dimension getMinimumSize()
      return new Dimension(5, 5);
    public Dimension getMaximumSize()
      return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
    public void paintTriangle(Graphics g, int x, int y, int size,
                  int direction, boolean isEnabled)
      Color oldColor = g.getColor();
      int mid, i, j;
      j = 0;
      size = Math.max(size, 2);
      mid = (size / 2) - 1;
      g.translate(x, y);
      if (isEnabled)
        g.setColor(darkShadow);
      else
        g.setColor(shadow);
      switch (direction)
        case NORTH:
          for (i = 0; i < size; i++)
            g.drawLine(mid - i, i, mid + i, i);
          if (!isEnabled)
            g.setColor(highlight);
            g.drawLine(mid - i + 2, i, mid + i, i);
          break;
        case SOUTH:
          if (!isEnabled)
            g.translate(1, 1);
            g.setColor(highlight);
            for (i = size - 1; i >= 0; i--)
              g.drawLine(mid - i, j, mid + i, j);
              j++;
            g.translate(-1, -1);
            g.setColor(shadow);
          j = 0;
          for (i = size - 1; i >= 0; i--)
            g.drawLine(mid - i, j, mid + i, j);
            j++;
          break;
        case WEST:
          for (i = 0; i < size; i++)
            g.drawLine(i, mid - i, i, mid + i);
          if (!isEnabled)
            g.setColor(highlight);
            g.drawLine(i, mid - i + 2, i, mid + i);
          break;
        case EAST:
          if (!isEnabled)
            g.translate(1, 1);
            g.setColor(highlight);
            for (i = size - 1; i >= 0; i--)
              g.drawLine(j, mid - i, j, mid + i);
              j++;
            g.translate(-1, -1);
            g.setColor(shadow);
          j = 0;
          for (i = size - 1; i >= 0; i--)
            g.drawLine(j, mid - i, j, mid + i);
            j++;
          break;
      g.translate(-x, -y);
      g.setColor(oldColor);
}

Answer 1

Darkness and blindness are away !
First line of the constructor :
public TreeComboBox(TreeModel aTreeModel)
    new BorderLayout(0, 0);
}I will reborn as a pumpkin !