Dynamic add items to JComboBox (value + icon = jlabel)

Question

I use DefaultComboBoxModel to add specific items to my JComboBox (String text, Icon icon). But something goes wrong. When I add those two items to my combo model it looks like this:

ComboBoxWindow: 

              [icon          ]

              [icon     value]

In summary, my code for combobox looks like this:

private JComboBox combobox;
...
DefaultComboBoxModel model = new DefaultComboBoxModel();
combobox = new JComboBox(model);
...
/*
 * I use JButton for 'sending' hex value taken from JTextField to 'combobox'
 * with help of 'addToComboBox()' method
 */
 public void addToComboBox() {

    String value = field.getText().toString();     // getin' text from 'left' JTextField

    Color color = tcc.getColor();                  // getin' color from some other JLabel
    ColorSwatch icon = new ColorSwatch(10, true);  // using some custom method to create little square icon
    icon.setColor(color);     // seting color of created icon

    combobox.addItem(icon);
    combobox.addItem(value);
 }

I considered using ListCellRenderer, but I don't know how can I 'tell' it that it should render, for example, a JLabel component by using 'value' and 'icon' simultaneously. It's very important for me to have possibility to add those items dynamically by using a JButton.

Answer 1

I did it & it works now just fine :) Basicaly 1. I've used a DefaultComboBoxModel, 2. I've added it to my JComboBox, 3. I've added a custom ListCellRenderer which 'translates' taken string (e.g. '#FFFFFF') to a icon & proper text and at the end creates a JLabel with that newborn icon and text.

/**
 * Main Class
 */
public class ColorChooser {
   ...
   public ColorChooser() {
      ...
      DefaultComboBoxModel<String> model = new DefaultComboBoxModel<String>();
      JComboBox combobox = new JComboBox<String>(model);
      combobox.setEditable(false);
      cobobox.setRenderer(new ComboRenderer());
      ...
   }
   ...
}

/**
 * Renderer Class
 */
public class ComboRenderer extends JLabel implements ListCellRenderer<Object> {

   public ComboRenderer() {

   }

   public Component getListCellRendererComponent(JList<?> list, Object value, int index, boolean isSelected, boolean cellHasFocus) {

      setFont(newFont("Consolas", Font.PLAIN, 14));
      setOpaque(true);

      String hex;

      if (value != null) {

         /*
          * So basically I add to my 'model' in ColorChooser main class only Strings
          * which I get e.g. from some JTextField. 
          * On base of this String I create icon for future JLabel
          * and I set String 'value' as text for it.
          */
         hex = value.toString();

         Color color = HexToRgb(hex); //Method which translates String to Color

         ColorSwatch icon = new ColorSwatch(10, true); // ColorSwatch is a method which creates specific square icon (in this case a little square)
         icon.setColor(color);

         setText(hex);
         setIcon(icon);
      }
      return this;
   }

   /*
    * My translate method which translates given String to a specific color value
    * (RGB/RGBA)
    */
   public Color HexToRgb(String colorStr) {

      Color color = null;

      // For String hex value '#RRGGBB'
      if (colorStr.length() == 7) {

         color = new Color(
            Integer.valueOf(colorStr.substring(1, 3), 16),
            Integer.valueOf(colorStr.substring(3, 5), 16),
            Integer.valueOf(colorStr.substring(5, 7), 16));

        // For String hex value '#AARRGGBB'
      } else if (colorStr.length() == 9) {

         color = new Color(
            Integer.valueOf(colorStr.substring(3, 5), 16),
            Integer.valueOf(colorStr.substring(5, 7), 16),
            Integer.valueOf(colorStr.substring(7, 9), 16),
            Integer.valueOf(colorStr.substring(1, 3), 16));

        // For String hex value '0xRRGGBB'
      } else if (colorStr.length() == 8) {

         color = new Color(
            Integer.valueOf(colorStr.substring(2, 4), 16),
            Integer.valueOf(colorStr.substring(4, 6), 16),
            Integer.valueOf(colorStr.substring(6, 8), 16));

        // For String hex value '0xAARRGGBB'
      } else if (colorStr.length() == 10) {

         color = new Color(
            Integer.valueOf(colorStr.substring(4, 6), 16),
            Integer.valueOf(colorStr.substring(6, 8), 16),
            Integer.valueOf(colorStr.substring(8, 10), 16),
            Integer.valueOf(colorStr.substring(2, 4), 16));

      } else
         JOptionPane.showMessageDialog(null, "Something wen wrong... :|");

      return color;
   }
}

And with renderer like this I can just add items to my combobox...

try {

   String hex = jtextfield.getText();
   boolean canI = CheckHexValue(hex); //Method for checkin' if 'hex' String fits some specific terms

   if (canI) {

      combobox.insertItemAt(hex, 0);
      combobox.setSelectedIndex(0);
   }
} catch (Exception e) {
   JOptionPane.showMessageDialog(null, e);
}

...and we are home now. Hope that code will help someone :)