Package org.jdesktop.swingx.combobox

Class EnumComboBoxModel<E extends Enum<E>>

java.lang.Object
javax.swing.AbstractListModel<E>
org.jdesktop.swingx.combobox.ListComboBoxModel<E>
org.jdesktop.swingx.combobox.EnumComboBoxModel<E>
All Implemented Interfaces:
ActionListener, Serializable, EventListener, ComboBoxModel<E>, ListModel<E>
public class EnumComboBoxModel<E extends Enum<E>> extends ListComboBoxModel<E>

A ComboBoxModel implementation that safely wraps an Enum. It allows the developer to directly use an enum as their model for a combobox without any extra work, though the display can can be further customized.

Simple Usage

The simplest usage is to wrap an enum inside the EnumComboBoxModel and then set it as the model on the combo box. The combo box will then appear on screen with each value in the enum as a value in the combobox.

ex: 


  enum MyEnum { GoodStuff, BadStuff };
  ...
  JComboBox combo = new JComboBox();
  combo.setModel(new EnumComboBoxModel(MyEnum.class));

Type safe access

By using generics and co-variant types you can make accessing elements from the model be completely typesafe. ex: 


 EnumComboBoxModel<MyEnum> enumModel = new EnumComboBoxModel<MyEnum1>(
         MyEnum1.class);
 
 MyEnum first = enumModel.getElement(0);
 
 MyEnum selected = enumModel.getSelectedItem();

Advanced Usage

Since the exact toString() value of each enum constant may not be exactly what you want on screen (the values won't have spaces, for example) you can override to toString() method on the values when you declare your enum. Thus the display value is localized to the enum and not in your GUI code. ex: 


    private enum MyEnum {GoodStuff, BadStuff;
        public String toString() {
           switch(this) {
               case GoodStuff: return "Some Good Stuff";
               case BadStuff: return "Some Bad Stuff";
           }
           return "ERROR";
        }
    };
Note: if more than one enum constant returns the same String via toString(), this model will throw an exception on creation.
Author:
joshy, Karl Schaefer
See Also:

  • Constructor Details

    • EnumComboBoxModel

      public EnumComboBoxModel(Class<E> en)
      Creates an EnumComboBoxModel for the enum represent by the Class en.
      Parameters:
      en - the enum class type
      Throws:
      IllegalArgumentException - if the Enum.toString returns the same value for more than one constant

  • Method Details

    • setSelectedItem

      public void setSelectedItem(Object anItem)
      Set the selected item. The implementation of this method should notify all registered ListDataListeners that the contents have changed.
      Specified by:
      setSelectedItem in interface ComboBoxModel<E extends Enum<E>>
      Overrides:
      setSelectedItem in class ListComboBoxModel<E extends Enum<E>>
      Parameters:
      anItem - the list object to select or null to clear the selection