PartialDisableComboBox.java

package org.lodder.subtools.multisubdownloader.gui.extra;

import java.awt.Component;
import java.util.ArrayList;

import javax.swing.JComboBox;
import javax.swing.JList;
import javax.swing.plaf.basic.BasicComboBoxRenderer;

/**
 * 
 * @author http://vetruvet.blogspot.com/2011/03/jcombobox-with-disabled-items.html
 */
public class PartialDisableComboBox extends JComboBox<Object> {
  private static final long serialVersionUID = -1690671707274328126L;

  private ArrayList<Boolean> itemsState = new ArrayList<Boolean>();

  @SuppressWarnings("unchecked")
  public PartialDisableComboBox(Object[] items) {
    super();
    for (Object o : items) {
      addItem(o);
    }
    this.setRenderer(new BasicComboBoxRenderer() {
      private static final long serialVersionUID = -2774241371293899669L;

      @SuppressWarnings("rawtypes")
      @Override
      public Component getListCellRendererComponent(JList list, Object value, int index,
          boolean isSelected, boolean cellHasFocus) {
        Component c =
            super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
        boolean disabled = index >= 0 && index < itemsState.size() && !itemsState.get(index);
        c.setEnabled(!disabled);
        c.setFocusable(!disabled);
        return c;
      }
    });
  }

  @Override
  public void addItem(Object item) {
    this.addItem(item, true);
  }

  public void addItem(Object item, boolean enabled) {
    super.addItem(item);
    itemsState.add(enabled);
  }

  @Override
  public void insertItemAt(Object item, int index) {
    this.insertItemAt(item, index, true);
  }

  public void insertItemAt(Object item, int index, boolean enabled) {
    super.insertItemAt(item, index);
    itemsState.add(index, enabled);
  }

  @Override
  public void removeAllItems() {
    super.removeAllItems();
    itemsState.clear();
  }

  @Override
  public void removeItemAt(int index) {
    if (index < 0 || index >= itemsState.size())
      throw new IllegalArgumentException("Item Index out of Bounds!");
    super.removeItemAt(index);
    itemsState.remove(index);
  }

  @Override
  public void removeItem(Object item) {
    for (int q = 0; q < this.getItemCount(); q++) {
      if (this.getItemAt(q) == item) itemsState.remove(q);
    }
    super.removeItem(item);
  }

  @Override
  public void setSelectedIndex(int index) {
    if (index < 0 || index >= itemsState.size())
      throw new IllegalArgumentException("Item Index out of Bounds!");
    if (itemsState.get(index)) super.setSelectedIndex(index);
  }

  public void setItemEnabled(int index, boolean enabled) {
    if (index < 0 || index >= itemsState.size())
      throw new IllegalArgumentException("Item Index out of Bounds!");
    itemsState.set(index, enabled);
  }

  public boolean isItemEnabled(int index) {
    if (index < 0 || index >= itemsState.size())
      throw new IllegalArgumentException("Item Index out of Bounds!");
    return itemsState.get(index);
  }
}