Module java.desktop

Package javax.swing

Class JComboBox<E>

java.lang.Object

java.awt.Component

java.awt.Container

javax.swing.JComponent

javax.swing.JComboBox<E>

Type Parameters:

E - the type of the elements of this combo box

All Implemented Interfaces:

ActionListener, ImageObserver, ItemSelectable, MenuContainer, Serializable, EventListener, Accessible, ListDataListener

@JavaBean(defaultProperty="UI",
          description="A combination of a text field and a drop-down list.")
public class JComboBox<E>
extends JComponent
implements ItemSelectable, ListDataListener, ActionListener, Accessible

A component that combines a button or editable field and a drop-down list. The user can select a value from the drop-down list, which appears at the user's request. If you make the combo box editable, then the combo box includes an editable field into which the user can type a value.

Warning: Swing is not thread safe. For more information see Swing's Threading Policy.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans has been added to the java.beans package. Please see XMLEncoder.

See How to Use Combo Boxes in The Java Tutorial for further information.

Since:

1.2

See Also:

• ComboBoxModel
• DefaultComboBoxModel

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	JComboBox.AccessibleJComboBox	This class implements accessibility support for the JComboBox class.
static interface	JComboBox.KeySelectionManager	The interface that defines a KeySelectionManager.

Nested classes/interfaces declared in class javax.swing.JComponent

JComponent.AccessibleJComponent

Nested classes/interfaces declared in class java.awt.Container

Container.AccessibleAWTContainer

Nested classes/interfaces declared in class java.awt.Component

Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

Fields

Modifier and Type	Field	Description
protected String	actionCommand	This protected field is implementation specific.
protected ComboBoxModel<E>	dataModel	This protected field is implementation specific.
protected ComboBoxEditor	editor	This protected field is implementation specific.
protected boolean	isEditable	This protected field is implementation specific.
protected JComboBox.KeySelectionManager	keySelectionManager	This protected field is implementation specific.
protected boolean	lightWeightPopupEnabled	This protected field is implementation specific.
protected int	maximumRowCount	This protected field is implementation specific.
protected ListCellRenderer<? super E>	renderer	This protected field is implementation specific.
protected Object	selectedItemReminder	This protected field is implementation specific.

Fields declared in class javax.swing.JComponent

listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields declared in class java.awt.Component

accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields declared in interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

Constructors

Constructor	Description
JComboBox()	Creates a JComboBox with a default data model.
JComboBox(E[] items)	Creates a JComboBox that contains the elements in the specified array.
JComboBox(Vector<E> items)	Creates a JComboBox that contains the elements in the specified Vector.
JComboBox(ComboBoxModel<E> aModel)	Creates a JComboBox that takes its items from an existing ComboBoxModel.

Method Summary

Modifier and Type	Method	Description
void	actionPerformed(ActionEvent e)	This method is public as an implementation side effect.
protected void	actionPropertyChanged(Action action, String propertyName)	Updates the combobox's state in response to property changes in associated action.
void	addActionListener(ActionListener l)	Adds an ActionListener.
void	addItem(E item)	Adds an item to the item list.
void	addItemListener(ItemListener aListener)	Adds an ItemListener.
void	addPopupMenuListener(PopupMenuListener l)	Adds a PopupMenu listener which will listen to notification messages from the popup portion of the combo box.
void	configureEditor(ComboBoxEditor anEditor, Object anItem)	Initializes the editor with the specified item.
protected void	configurePropertiesFromAction(Action a)	Sets the properties on this combobox to match those in the specified Action.
void	contentsChanged(ListDataEvent e)	This method is public as an implementation side effect.
protected PropertyChangeListener	createActionPropertyChangeListener(Action a)	Creates and returns a PropertyChangeListener that is responsible for listening for changes from the specified Action and updating the appropriate properties.
protected JComboBox.KeySelectionManager	createDefaultKeySelectionManager()	Returns an instance of the default key-selection manager.
protected void	fireActionEvent()	Notifies all listeners that have registered interest for notification on this event type.
protected void	fireItemStateChanged(ItemEvent e)	Notifies all listeners that have registered interest for notification on this event type.
void	firePopupMenuCanceled()	Notifies PopupMenuListeners that the popup portion of the combo box has been canceled.
void	firePopupMenuWillBecomeInvisible()	Notifies PopupMenuListeners that the popup portion of the combo box has become invisible.
void	firePopupMenuWillBecomeVisible()	Notifies PopupMenuListeners that the popup portion of the combo box will become visible.
AccessibleContext	getAccessibleContext()	Gets the AccessibleContext associated with this JComboBox.
Action	getAction()	Returns the currently set Action for this ActionEvent source, or null if no Action is set.
String	getActionCommand()	Returns the action command that is included in the event sent to action listeners.
ActionListener[]	getActionListeners()	Returns an array of all the ActionListeners added to this JComboBox with addActionListener().
ComboBoxEditor	getEditor()	Returns the editor used to paint and edit the selected item in the JComboBox field.
E	getItemAt(int index)	Returns the list item at the specified index.
int	getItemCount()	Returns the number of items in the list.
ItemListener[]	getItemListeners()	Returns an array of all the ItemListeners added to this JComboBox with addItemListener().
JComboBox.KeySelectionManager	getKeySelectionManager()	Returns the list's key-selection manager.
int	getMaximumRowCount()	Returns the maximum number of items the combo box can display without a scrollbar
ComboBoxModel<E>	getModel()	Returns the data model currently used by the JComboBox.
PopupMenuListener[]	getPopupMenuListeners()	Returns an array of all the PopupMenuListeners added to this JComboBox with addPopupMenuListener().
E	getPrototypeDisplayValue()	Returns the "prototypical display" value - an Object used for the calculation of the display height and width.
ListCellRenderer<? super E>	getRenderer()	Returns the renderer used to display the selected item in the JComboBox field.
int	getSelectedIndex()	Returns the first item in the list that matches the given item.
Object	getSelectedItem()	Returns the current selected item.
Object[]	getSelectedObjects()	Returns an array containing the selected item.
ComboBoxUI	getUI()	Returns the L&F object that renders this component.
String	getUIClassID()	Returns the name of the L&F class that renders this component.
void	hidePopup()	Causes the combo box to close its popup window.
void	insertItemAt(E item, int index)	Inserts an item into the item list at a given index.
protected void	installAncestorListener()	Registers ancestor listener so that it will receive AncestorEvents when it or any of its ancestors move or are made visible or invisible.
void	intervalAdded(ListDataEvent e)	This method is public as an implementation side effect.
void	intervalRemoved(ListDataEvent e)	This method is public as an implementation side effect.
boolean	isEditable()	Returns true if the JComboBox is editable.
boolean	isLightWeightPopupEnabled()	Gets the value of the lightWeightPopupEnabled property.
boolean	isPopupVisible()	Determines the visibility of the popup.
protected String	paramString()	Returns a string representation of this JComboBox.
void	processKeyEvent(KeyEvent e)	Handles KeyEvents, looking for the Tab key.
void	removeActionListener(ActionListener l)	Removes an ActionListener.
void	removeAllItems()	Removes all items from the item list.
void	removeItem(Object anObject)	Removes an item from the item list.
void	removeItemAt(int anIndex)	Removes the item at anIndex This method works only if the JComboBox uses a mutable data model.
void	removeItemListener(ItemListener aListener)	Removes an ItemListener.
void	removePopupMenuListener(PopupMenuListener l)	Removes a PopupMenuListener.
protected void	selectedItemChanged()	This protected method is implementation specific.
boolean	selectWithKeyChar(char keyChar)	Selects the list item that corresponds to the specified keyboard character and returns true, if there is an item corresponding to that character.
void	setAction(Action a)	Sets the Action for the ActionEvent source.
void	setActionCommand(String aCommand)	Sets the action command that should be included in the event sent to action listeners.
void	setEditable(boolean aFlag)	Determines whether the JComboBox field is editable.
void	setEditor(ComboBoxEditor anEditor)	Sets the editor used to paint and edit the selected item in the JComboBox field.
void	setEnabled(boolean b)	Enables the combo box so that items can be selected.
void	setKeySelectionManager(JComboBox.KeySelectionManager aManager)	Sets the object that translates a keyboard character into a list selection.
void	setLightWeightPopupEnabled(boolean aFlag)	Sets the lightWeightPopupEnabled property, which provides a hint as to whether or not a lightweight Component should be used to contain the JComboBox, versus a heavyweight Component such as a Panel or a Window.
void	setMaximumRowCount(int count)	Sets the maximum number of rows the JComboBox displays.
void	setModel(ComboBoxModel<E> aModel)	Sets the data model that the JComboBox uses to obtain the list of items.
void	setPopupVisible(boolean v)	Sets the visibility of the popup.
void	setPrototypeDisplayValue(E prototypeDisplayValue)	Sets the prototype display value used to calculate the size of the display for the UI portion.
void	setRenderer(ListCellRenderer<? super E> aRenderer)	Sets the renderer that paints the list items and the item selected from the list in the JComboBox field.
void	setSelectedIndex(int anIndex)	Selects the item at index anIndex.
void	setSelectedItem(Object anObject)	Sets the selected item in the combo box display area to the object in the argument.
void	setUI(ComboBoxUI ui)	Sets the L&F object that renders this component.
void	showPopup()	Causes the combo box to display its popup window.
void	updateUI()	Resets the UI property to a value from the current look and feel.

Methods declared in class javax.swing.JComponent

addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale,