Problems with BasicComboBoxEditor

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hi,

I am using an editable ComboBox with BasicComboBoxEditor
(minimal example attached) with GTK or Nimbus L&Fs:

  JComboBox comboBox = new JComboBox();
  comboBox.setEditable(true);
  comboBox.setEditor(new BasicComboBoxEditor());

I am having two problems with this:

#1. the first character in the editable combobox (which uses a
    JTextField internally) cannot show the first letter completely (too
    few left padding, see attached minimal example)

#2. The Background color of the editable combo box is white
    (as opposed to normal comboboxes, which are grey, depending on L&F)

#1 can be worked around by using a MetalComboBoxEditor (without using
   metal L&F) instead of the BasicComboBoxEditor. I think this solution
   is satisfactory, but does there happen to be a better solution?

#2: Concerning the background color issue, I managed to change the
    background color of the JTextField:

class ComboBoxEditorWithBGColor extends MetalComboBoxEditor
{
    public ComboBoxEditorWithBGColor()
    {
        // change the background color of the editor component that the
        // ComboBoxEditor uses for editing
        Color c = UIManager.getLookAndFeelDefaults().getColor("ComboBox.background");
        editor.setBackground(new Color(c.getRed(), c.getGreen(), c.getBlue()));
    }
}

....but not the background color of the combobox items that appear
   when you "unfold" the combobox. I tried to set a simple renderer:

class SimpleListCellRenderer implements ListCellRenderer
{
        public Component getListCellRendererComponent(JList list, Object value,
                                                      int index, boolean isSelected, boolean cellHasFocus) {
          JLabel label = new JLabel(value.toString());
          label.setBackground(Color.RED);
          label.setOpaque(true);
          return label;
      }

}

.... but this seems to be ignored in the editable combobox.

A workaround is to subclass MetalBasicComboBoxUI:

class MyBasicComboBoxUI extends MetalBasicComboBoxUI
{
    public MyBasicComboBoxUI()
    {
    }
    public void setBG()
    {
        Color c = UIManager.getLookAndFeelDefaults().getColor("ComboBox.background");
        listBox.setBackground(new Color(c.getRed(), c.getGreen(), c.getBlue()));
    }
}

and set it on the combo:

       MyBasicComboBoxUI ui = new MyBasicComboBoxUI();
       comboBox.setUI(ui);
       ui.setBG();

=> this works, but (of course) the combo box is rendered according to
metal L&F which does not fit in particularly well with non-metal L&F
(and the whole point of this hack is to make editable combo boxes look like
normal ones).
I also tried to use BasicComboBoxUI instead of MetalBasicComboBoxUI, but
then the handle is not drawn at all.

Thanks in Advance and Best Regards!
--
Felix Natter

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Content-Type: text/x-java
Content-Disposition: inline; filename=TestComboBox.java

import javax.swing.*;
import java.awt.*;
import javax.swing.plaf.basic.*;
import javax.swing.plaf.metal.*;

class MyBasicComboBoxUI extends MetalComboBoxUI
{
    public MyBasicComboBoxUI()
    {
    }
    public void setBG()
    {
        Color c = UIManager.getLookAndFeelDefaults().getColor("ComboBox.background");
        listBox.setBackground(new Color(c.getRed(), c.getGreen(), c.getBlue()));
    }
}

class ComboBoxEditorWithBGColor extends MetalComboBoxEditor
{
    public ComboBoxEditorWithBGColor()
    {
        Color c = UIManager.getLookAndFeelDefaults().getColor("ComboBox.background");
        editor.setBackground(new Color(c.getRed(), c.getGreen(), c.getBlue()));
        
    }
}

class SimpleListCellRenderer implements ListCellRenderer
{
        public Component getListCellRendererComponent(JList list, Object value,
                                                      int index, boolean isSelected, boolean cellHasFocus) {
          JLabel label = new JLabel(value.toString());
          label.setBackground(Color.RED);
          label.setOpaque(true);
          return label;
      }

}

public class TestComboBox
{
    public static void main(String[] args) throws Exception
        {
            //UIManager.setLookAndFeel("com.sun.java.swing.plaf.gtk.GTKLookAndFeel");
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");

            JFrame frame = new JFrame();
            JPanel panel = new JPanel();

            JComboBox comboBox = new JComboBox();
            comboBox.setEditable(true);
            //comboBox.setEditor(new BasicComboBoxEditor());
            comboBox.setEditor(new ComboBoxEditorWithBGColor());
            //comboBox.setEditor(new MetalComboBoxEditor());
            //comboBox.setRenderer(new SimpleListCellRenderer());
            
            MyBasicComboBoxUI ui = new MyBasicComboBoxUI();
            comboBox.setUI(ui);
            ui.setBG();

            panel.add(new JButton("foo"));

            panel.add(comboBox);
            frame.getContentPane().add(panel);
            frame.pack();
            frame.setVisible(true);
        }
}

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