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javax.swing
Class JComboBox
java.lang.Object
java.awt.Component
java.awt.Container
javax.swing.JComponent
javax.swing.JComboBox
-
All Implemented Interfaces:
-
Accessible
,
ActionListener
,
EventListener
,
ImageObserver
,
ItemSelectable
,
ListDataListener
,
MenuContainer
,
Serializable
-
public class
JComboBox
-
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.
For the keyboard keys used by this component in the standard Look and Feel (L&F) renditions, see the
JComboBox key assignments
.
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
TM
has been added to the java.beans package. Please see
XMLEncoder
.
See
How to Use Combo Boxes
in
The Java Tutorial
for further information.
-
See Also:
-
ComboBoxModel
,
DefaultComboBoxModel
Nested Class Summary
|
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 inherited from class java.awt.
Component
|
Component.AccessibleAWTComponent
,
Component.BltBufferStrategy
,
Component.FlipBufferStrategy
|
Field Summary
|
protected
String
|
actionCommand
This protected field is implementation specific. |
protected
ComboBoxModel
|
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
|
renderer
This protected field is implementation specific. |
protected
Object
|
selectedItemReminder
This protected field is implementation specific. |
Fields inherited from interface java.awt.image.
ImageObserver
|
ABORT
,
ALLBITS
,
ERROR
,
FRAMEBITS
,
HEIGHT
,
PROPERTIES
,
SOMEBITS
,
WIDTH
|
Constructor Summary
|
JComboBox
()
Creates a JComboBox with a default data model. |
JComboBox
(
ComboBoxModel
aModel)
Creates a JComboBox that takes it's items from an existing ComboBoxModel. |
JComboBox
(
Object
[] items)
Creates a JComboBox that contains the elements in the specified array. |
JComboBox
(
Vector
items)
Creates a JComboBox that contains the elements in the specified Vector. |
Method Summary
|
void |
actionPerformed
(
ActionEvent
e)
This method is public as an implementation side effect. |
void |
addActionListener
(
ActionListener
l)
Adds an ActionListener. |
void |
addItem
(
Object
anObject)
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)
Factory method which sets the ActionEvent source's properties according to values from the Action instance. |
void |
contentsChanged
(
ListDataEvent
e)
This method is public as an implementation side effect. |
protected
PropertyChangeListener
|
createActionPropertyChangeListener
(
Action
a)
Factory method which creates the PropertyChangeListener used to update the ActionEvent source as properties change on its Action instance. |
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. |
Object
|
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
|
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(). |
Object
|
getPrototypeDisplayValue
()
Returns the "prototypical display" value - an Object used for the calculation of the display height and width. |
ListCellRenderer
|
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
(
Object
anObject, int index)
Inserts an item into the item list at a given index. |
protected void |
installAncestorListener
()
|
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
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
(
Object
prototypeDisplayValue)
Sets the prototype display value used to calculate the size of the display for the UI portion. |
void |
setRenderer
(
ListCellRenderer
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 inherited from class javax.swing.
JComponent
|
addAncestorListener
,
addNotify
,
addPropertyChangeListener
,
addPropertyChangeListener
,
addVetoableChangeListener
,
computeVisibleRect
,
contains
,
createToolTip
,
disable
,
enable
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
fireVetoableChange
,
getActionForKeyStroke
,
getActionMap
,
getAlignmentX
,
getAlignmentY
,
getAncestorListeners
,
getAutoscrolls
,
getBorder
,
getBounds
,
getClientProperty
,
getComponentGraphics
,
getComponentPopupMenu
,
getConditionForKeyStroke
,
getDebugGraphicsOptions
,
getDefaultLocale
,
getFontMetrics
,
getGraphics
,
getHeight
,
getInheritsPopupMenu
,
getInputMap
,
getInputMap
,
getInputVerifier
,
getInsets
,
getInsets
,
getListeners
,
getLocation
,
getMaximumSize
,
getMinimumSize
,
getNextFocusableComponent
,
getPopupLocation
getPreferredSize
,
getPreferredSize
getPropertyChangeListeners
,
getPropertyChangeListeners
,
getRegisteredKeyStrokes
,
getRootPane
,
getSize
,
getToolTipLocation
,
getToolTipText
,
getToolTipText
,
getTopLevelAncestor
,
getTransferHandler
,
getVerifyInputWhenFocusTarget
,
getVetoableChangeListeners
,
getVisibleRect
,
getWidth
,
getX
,
getY
,
grabFocus
,
isDoubleBuffered
,
isLightweightComponent
,
isManagingFocus
,
isMaximumSizeSet
,
isMinimumSizeSet
,
isOpaque
,
isOptimizedDrawingEnabled
,
isPaintingTile
,
isPreferredSizeSet
,
isRequestFocusEnabled
,
isValidateRoot
,
paint
,
paintBorder
,
paintChildren
,
paintComponent
,
paintImmediately
,
paintImmediately
,
print
,
printAll
,
printBorder
,
printChildren
,
printComponent
,
processComponentKeyEvent
,
processKeyBinding
,
processMouseEvent
,
processMouseMotionEvent
,
putClientProperty
,
registerKeyboardAction
,
registerKeyboardAction
,
removeAncestorListener
,
removeNotify
,
removePropertyChangeListener
,
removePropertyChangeListener
,
removeVetoableChangeListener
,
repaint
,
repaint
,
requestDefaultFocus
,
requestFocus
,
requestFocus
,
requestFocusInWindow
,
requestFocusInWindow
,
resetKeyboardActions
,
reshape
,
revalidate
,
scrollRectToVisible
,
setActionMap
,
setAlignmentX
,
setAlignmentY
,
setAutoscrolls
,
setBackground
,
setBorder
,
setComponentPopupMenu
,
setDebugGraphicsOptions
,
setDefaultLocale
,
setDoubleBuffered
,
setFocusTraversalKeys
,
setFont
,
setForeground
,
setInheritsPopupMenu
,
setInputMap
,
setInputVerifier
,
setMaximumSize
,
setMinimumSize
,
setNextFocusableComponent
,
setOpaque
,
setPreferredSize
,
setRequestFocusEnabled
,
setToolTipText
,
setTransferHandler
,
setUI
,
setVerifyInputWhenFocusTarget
,
setVisible
,
unregisterKeyboardAction
,
update
|
Methods inherited from class java.awt.
Container
|
add
,
add
,
add
,
add
,
add
,
addContainerListener
,
addImpl
,
addPropertyChangeListener
,
addPropertyChangeListener
,
applyComponentOrientation
,
areFocusTraversalKeysSet
,
countComponents
,
deliverEvent
,
doLayout
,
findComponentAt
,
findComponentAt
,
getComponent
,
getComponentAt
,
getComponentAt
,
getComponentCount
,
getComponents
,
getComponentZOrder
,
getContainerListeners
,
getFocusTraversalKeys
,
getFocusTraversalPolicy
,
getLayout
,
getMousePosition
,
insets
,
invalidate
,
isAncestorOf
,
isFocusCycleRoot
,
isFocusCycleRoot
,
isFocusTraversalPolicyProvider
,
isFocusTraversalPolicySet
,
layout
,
list
,
list
,
locate
,
minimumSize
,
paintComponents
,
preferredSize
,
printComponents
,
processContainerEvent
,
processEvent
,
remove
,
remove
,
removeAll
,
removeContainerListener
,
setComponentZOrder
setFocusCycleRoot
,
setFocusCycleRoot
setFocusTraversalKeys
,
setFocusTraversalPolicy
,
setFocusTraversalPolicyProvider
,
setLayout
,
transferFocusBackward
,
transferFocusDownCycle
,
validate
,
validateTree
|
Methods inherited from class java.awt.
Component
|
action
,
add
,
addComponentListener
,
addFocusListener
,
addHierarchyBoundsListener
,
addHierarchyListener
,
addInputMethodListener
,
addKeyListener
,
addMouseListener
,
addMouseMotionListener
,
addMouseWheelListener
,
bounds
,
checkImage
,
checkImage
,
coalesceEvents
,
contains
,
createImage
,
createImage
,
createVolatileImage
,
createVolatileImage
,
disableEvents
,
dispatchEvent
,
enable
,
enableEvents
,
enableInputMethods
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
firePropertyChange
,
getBackground
,
getBounds
,
getColorModel
,
getComponentListeners
,
getComponentOrientation
,
getCursor
,
getDropTarget
,
getFocusCycleRootAncestor
,
getFocusListeners
,
getFocusTraversalKeysEnabled
,
getFont
,
getFontMetrics
,
getForeground
,
getGraphicsConfiguration
,
getHierarchyBoundsListeners
,
getHierarchyListeners
,
getIgnoreRepaint
,
getInputContext
,
getInputMethodListeners
,
getInputMethodRequests
,
getKeyListeners
,
getLocale
,
getLocation
,
getLocationOnScreen
,
getMouseListeners
,
getMouseMotionListeners
,
getMousePosition
,
getMouseWheelListeners
,
getName
,
getParent
,
getPeer
,
getPropertyChangeListeners
,
getPropertyChangeListeners
,
getSize
,
getToolkit
,
getTreeLock
,
gotFocus
,
handleEvent
,
hasFocus
,
hide
,
imageUpdate
,
inside
,
isBackgroundSet
,
isCursorSet
,
isDisplayable
,
isEnabled
,
isFocusable
,
isFocusOwner
,
isFocusTraversable
,
isFontSet
,
isForegroundSet
,
isLightweight
,
isMaximumSizeSet
,
isMinimumSizeSet
,
isPreferredSizeSet
,
isShowing
,
isValid
,
isVisible
,
keyDown
,
keyUp
,
list
,
list
,
list
,
location
,
lostFocus
,
mouseDown
,
mouseDrag
,
mouseEnter
,
mouseExit
,
mouseMove
,
mouseUp
,
move
,
nextFocus
,
paintAll
,
postEvent
,
prepareImage
,
prepareImage
,
processComponentEvent
,
processFocusEvent
,
processHierarchyBoundsEvent
,
processHierarchyEvent
,
processInputMethodEvent
,
processMouseEvent
,
processMouseWheelEvent
,
remove
,
removeComponentListener
,
removeFocusListener
,
removeHierarchyBoundsListener
,
removeHierarchyListener
,
removeInputMethodListener
,
removeKeyListener
,
removeMouseListener
,
removeMouseMotionListener
,
removeMouseWheelListener
,
removePropertyChangeListener
,
removePropertyChangeListener
,
repaint
,
repaint
,
repaint
,
resize
,
resize
,
setBounds
,
setBounds
,
setComponentOrientation
,
setCursor
,
setDropTarget
,
setFocusable
,
setFocusTraversalKeysEnabled
,
setIgnoreRepaint
,
setLocale
,
setLocation
,
setLocation
,
setName
,
setSize
,
setSize
,
show
,
show
,
size
,
toString
,
transferFocus
,
transferFocusUpCycle
|
dataModel
protected ComboBoxModel dataModel
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
getModel()
,
setModel(javax.swing.ComboBoxModel)
renderer
protected ListCellRenderer renderer
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
getRenderer()
,
setRenderer(javax.swing.ListCellRenderer)
editor
protected ComboBoxEditor editor
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
getEditor()
,
setEditor(javax.swing.ComboBoxEditor)
maximumRowCount
protected int maximumRowCount
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
getMaximumRowCount()
,
setMaximumRowCount(int)
isEditable
protected boolean isEditable
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
isEditable
,
setEditable(boolean)
keySelectionManager
protected JComboBox.KeySelectionManager keySelectionManager
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
setKeySelectionManager(javax.swing.JComboBox.KeySelectionManager)
,
getKeySelectionManager()
actionCommand
protected String actionCommand
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
setActionCommand(java.lang.String)
,
getActionCommand()
lightWeightPopupEnabled
protected boolean lightWeightPopupEnabled
-
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.
-
See Also:
-
setLightWeightPopupEnabled(boolean)
,
isLightWeightPopupEnabled()
selectedItemReminder
protected Object selectedItemReminder
-
This protected field is implementation specific. Do not access directly or override.
JComboBox
public JComboBox(ComboBoxModel aModel)
-
Creates a JComboBox that takes it's items from an existing ComboBoxModel. Since the ComboBoxModel is provided, a combo box created using this constructor does not create a default combo box model and may impact how the insert, remove and add methods behave.
-
Parameters:
-
aModel - the ComboBoxModel that provides the displayed list of items
-
See Also:
-
DefaultComboBoxModel
JComboBox
public JComboBox(Object[] items)
-
Creates a JComboBox that contains the elements in the specified array. By default the first item in the array (and therefore the data model) becomes selected.
-
Parameters:
-
items - an array of objects to insert into the combo box
-
See Also:
-
DefaultComboBoxModel
JComboBox
public JComboBox(Vector items)
-
Creates a JComboBox that contains the elements in the specified Vector. By default the first item in the vector and therefore the data model) becomes selected.
-
Parameters:
-
items - an array of vectors to insert into the combo box
-
See Also:
-
DefaultComboBoxModel
JComboBox
public JComboBox()
-
Creates a JComboBox with a default data model. The default data model is an empty list of objects. Use addItem to add items. By default the first item in the data model becomes selected.
-
See Also:
-
DefaultComboBoxModel
installAncestorListener
protected void installAncestorListener()
-
-
setUI
public void setUI(ComboBoxUI ui)
-
Sets the L&F object that renders this component.
-
-
-
Parameters:
-
ui - the ComboBoxUI L&F object
-
See Also:
-
UIDefaults.getUI(javax.swing.JComponent)
updateUI
public void updateUI()
-
Resets the UI property to a value from the current look and feel.
-
-
Overrides:
-
updateUI
in class
JComponent
-
-
See Also:
-
JComponent.updateUI()
getUIClassID
public String getUIClassID()
-
Returns the name of the L&F class that renders this component.
-
-
Overrides:
-
getUIClassID
in class
JComponent
-
-
Returns:
-
the string "ComboBoxUI"
-
See Also:
-
JComponent.getUIClassID()
,
UIDefaults.getUI(javax.swing.JComponent)
getUI
public ComboBoxUI getUI()
-
Returns the L&F object that renders this component.
-
-
-
Returns:
-
the ComboBoxUI object that renders this component
setModel
public void setModel(ComboBoxModel aModel)
-
Sets the data model that the JComboBox uses to obtain the list of items.
-
-
-
Parameters:
-
aModel - the ComboBoxModel that provides the displayed list of items
getModel
public ComboBoxModel getModel()
-
Returns the data model currently used by the JComboBox.
-
-
-
Returns:
-
the ComboBoxModel that provides the displayed list of items
setLightWeightPopupEnabled
public 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. The decision of lightweight versus heavyweight is ultimately up to the JComboBox. Lightweight windows are more efficient than heavyweight windows, but lightweight and heavyweight components do not mix well in a GUI. If your application mixes lightweight and heavyweight components, you should disable lightweight popups. The default value for the lightWeightPopupEnabled property is true, unless otherwise specified by the look and feel. Some look and feels always use heavyweight popups, no matter what the value of this property.
See the article
Mixing Heavy and Light Components
on
The Swing Connection
This method fires a property changed event.
-
-
-
Parameters:
-
aFlag - if true, lightweight popups are desired
isLightWeightPopupEnabled
public boolean isLightWeightPopupEnabled()
-
Gets the value of the lightWeightPopupEnabled property.
-
-
-
Returns:
-
the value of the lightWeightPopupEnabled property
-
See Also:
-
setLightWeightPopupEnabled(boolean)
setEditable
public void setEditable(boolean aFlag)
-
Determines whether the JComboBox field is editable. An editable JComboBox allows the user to type into the field or selected an item from the list to initialize the field, after which it can be edited. (The editing affects only the field, the list item remains intact.) A non editable JComboBox displays the selected item in the field, but the selection cannot be modified.
-
-
-
Parameters:
-
aFlag - a boolean value, where true indicates that the field is editable
isEditable
public boolean isEditable()
-
Returns true if the JComboBox is editable. By default, a combo box is not editable.
-
-
-
Returns:
-
true if the JComboBox is editable, else false
setMaximumRowCount
public void setMaximumRowCount(int count)
-
Sets the maximum number of rows the JComboBox displays. If the number of objects in the model is greater than count, the combo box uses a scrollbar.
-
-
-
Parameters:
-
count - an integer specifying the maximum number of items to display in the list before using a scrollbar
getMaximumRowCount
public int getMaximumRowCount()
-
Returns the maximum number of items the combo box can display without a scrollbar
-
-
-
Returns:
-
an integer specifying the maximum number of items that are displayed in the list before using a scrollbar
setRenderer
public void setRenderer(ListCellRenderer aRenderer)
-
Sets the renderer that paints the list items and the item selected from the list in the JComboBox field. The renderer is used if the JComboBox is not editable. If it is editable, the editor is used to render and edit the selected item.
The default renderer displays a string or an icon. Other renderers can handle graphic images and composite items.
To display the selected item, aRenderer.getListCellRendererComponent is called, passing the list object and an index of -1.
-
-
-
Parameters:
-
aRenderer - the ListCellRenderer that displays the selected item
-
See Also:
-
setEditor(javax.swing.ComboBoxEditor)
getRenderer
public ListCellRenderer getRenderer()
-
Returns the renderer used to display the selected item in the JComboBox field.
-
-
-
Returns:
-
the ListCellRenderer that displays the selected item.
setEditor
public void setEditor(ComboBoxEditor anEditor)
-
Sets the editor used to paint and edit the selected item in the JComboBox field. The editor is used only if the receiving JComboBox is editable. If not editable, the combo box uses the renderer to paint the selected item.
-
-
-
Parameters:
-
anEditor - the ComboBoxEditor that displays the selected item
-
See Also:
-
setRenderer(javax.swing.ListCellRenderer)
getEditor
public ComboBoxEditor getEditor()
-
Returns the editor used to paint and edit the selected item in the JComboBox field.
-
-
-
Returns:
-
the ComboBoxEditor that displays the selected item
setSelectedItem
public void setSelectedItem(Object anObject)
-
Sets the selected item in the combo box display area to the object in the argument. If anObject is in the list, the display area shows anObject selected.
If anObject is
not
in the list and the combo box is uneditable, it will not change the current selection. For editable combo boxes, the selection will change to anObject.
If this constitutes a change in the selected item, ItemListeners added to the combo box will be notified with one or two ItemEvents. If there is a current selected item, an ItemEvent will be fired and the state change will be ItemEvent.DESELECTED. If anObject is in the list and is not currently selected then an ItemEvent will be fired and the state change will be ItemEvent.SELECTED.
ActionListeners added to the combo box will be notified with an ActionEvent when this method is called.
-
-
-
Parameters:
-
anObject - the list object to select; use null to clear the selection
getSelectedItem
public Object getSelectedItem()
-
Returns the current selected item.
If the combo box is editable, then this value may not have been added to the combo box with addItem, insertItemAt or the data constructors.
-
-
-
Returns:
-
the current selected Object
-
See Also:
-
setSelectedItem(java.lang.Object)
setSelectedIndex
public void setSelectedIndex(int anIndex)
-
Selects the item at index anIndex.
-
-
-
Parameters:
-
anIndex - an integer specifying the list item to select, where 0 specifies the first item in the list and -1 indicates no selection
-
Throws:
-
IllegalArgumentException
- if anIndex < -1 or anIndex is greater than or equal to size
getSelectedIndex
public int getSelectedIndex()
-
Returns the first item in the list that matches the given item. The result is not always defined if the JComboBox allows selected items that are not in the list. Returns -1 if there is no selected item or if the user specified an item which is not in the list.
-
-
-
Returns:
-
an integer specifying the currently selected list item, where 0 specifies the first item in the list; or -1 if no item is selected or if the currently selected item is not in the list
getPrototypeDisplayValue
public Object getPrototypeDisplayValue()
-
Returns the "prototypical display" value - an Object used for the calculation of the display height and width.
-
-
-
Returns:
-
the value of the prototypeDisplayValue property
-
Since:
-
1.4
-
See Also:
-
setPrototypeDisplayValue(java.lang.Object)
setPrototypeDisplayValue
public void setPrototypeDisplayValue(Object prototypeDisplayValue)
-
Sets the prototype display value used to calculate the size of the display for the UI portion.
If a prototype display value is specified, the preferred size of the combo box is calculated by configuring the renderer with the prototype display value and obtaining its preferred size. Specifying the preferred display value is often useful when the combo box will be displaying large amounts of data. If no prototype display value has been specified, the renderer must be configured for each value from the model and its preferred size obtained, which can be relatively expensive.
-
-
-
Parameters:
-
prototypeDisplayValue -
-
Since:
-
1.4
-
See Also:
-
getPrototypeDisplayValue()
addItem
public void addItem(Object anObject)
-
Adds an item to the item list. This method works only if the JComboBox uses a mutable data model.
Warning: Focus and keyboard navigation problems may arise if you add duplicate String objects. A workaround is to add new objects instead of String objects and make sure that the toString() method is defined. For example:
comboBox.addItem(makeObj("Item 1"));
comboBox.addItem(makeObj("Item 1"));
...
private Object makeObj(final String item) {
return new Object() { public String toString() { return item; } };
}
-
-
-
Parameters:
-
anObject - the Object to add to the list
-
See Also:
-
MutableComboBoxModel
insertItemAt
public void insertItemAt(Object anObject,
int index)
-
Inserts an item into the item list at a given index. This method works only if the JComboBox uses a mutable data model.
-
-
-
Parameters:
-
anObject - the Object to add to the list
-
index - an integer specifying the position at which to add the item
-
See Also:
-
MutableComboBoxModel
removeItem
public void removeItem(Object anObject)
-
Removes an item from the item list. This method works only if the JComboBox uses a mutable data model.
-
-
-
Parameters:
-
anObject - the object to remove from the item list
-
See Also:
-
MutableComboBoxModel
removeItemAt
public void removeItemAt(int anIndex)
-
Removes the item at anIndex This method works only if the JComboBox uses a mutable data model.
-
-
-
Parameters:
-
anIndex - an int specifying the index of the item to remove, where 0 indicates the first item in the list
-
See Also:
-
MutableComboBoxModel
removeAllItems
public void removeAllItems()
-
Removes all items from the item list.
-
-
showPopup
public void showPopup()
-
Causes the combo box to display its popup window.
-
-
-
See Also:
-
setPopupVisible(boolean)
hidePopup
public void hidePopup()
-
Causes the combo box to close its popup window.
-
-
-
See Also:
-
setPopupVisible(boolean)
setPopupVisible
public void setPopupVisible(boolean v)
-
Sets the visibility of the popup.
-
-
isPopupVisible
public boolean isPopupVisible()
-
Determines the visibility of the popup.
-
-
-
Returns:
-
true if the popup is visible, otherwise returns false
addItemListener
public void addItemListener(ItemListener aListener)
-
Adds an ItemListener.
aListener will receive one or two ItemEvents when the selected item changes.
-
-
Specified by:
-
addItemListener
in interface
ItemSelectable
-
-
Parameters:
-
aListener - the ItemListener that is to be notified
-
See Also:
-
setSelectedItem(java.lang.Object)
removeItemListener
public void removeItemListener(ItemListener aListener)
-
Removes an ItemListener.
-
-
Specified by:
-
removeItemListener
in interface
ItemSelectable
-
-
Parameters:
-
aListener - the ItemListener to remove
-
See Also:
-
ItemEvent
getItemListeners
public ItemListener[] getItemListeners()
-
Returns an array of all the ItemListeners added to this JComboBox with addItemListener().
-
-
-
Returns:
-
all of the ItemListeners added or an empty array if no listeners have been added
-
Since:
-
1.4
addActionListener
public void addActionListener(ActionListener l)
-
Adds an ActionListener.
The ActionListener will receive an ActionEvent when a selection has been made. If the combo box is editable, then an ActionEvent will be fired when editing has stopped.
-
-
-
Parameters:
-
l - the ActionListener that is to be notified
-
See Also:
-
setSelectedItem(java.lang.Object)
removeActionListener
public void removeActionListener(ActionListener l)
-
Removes an ActionListener.
-
-
-
Parameters:
-
l - the ActionListener to remove
getActionListeners
public ActionListener[] getActionListeners()
-
Returns an array of all the ActionListeners added to this JComboBox with addActionListener().
-
-
-
Returns:
-
all of the ActionListeners added or an empty array if no listeners have been added
-
Since:
-
1.4
addPopupMenuListener
public void addPopupMenuListener(PopupMenuListener l)
-
Adds a PopupMenu listener which will listen to notification messages from the popup portion of the combo box.
For all standard look and feels shipped with Java 2, the popup list portion of combo box is implemented as a JPopupMenu. A custom look and feel may not implement it this way and will therefore not receive the notification.
-
-
-
Parameters:
-
l - the PopupMenuListener to add
-
Since:
-
1.4
removePopupMenuListener
public void removePopupMenuListener(PopupMenuListener l)
-
Removes a PopupMenuListener.
-
-
-
Parameters:
-
l - the PopupMenuListener to remove
-
Since:
-
1.4
-
See Also:
-
addPopupMenuListener(javax.swing.event.PopupMenuListener)
getPopupMenuListeners
public PopupMenuListener[] getPopupMenuListeners()
-
Returns an array of all the PopupMenuListeners added to this JComboBox with addPopupMenuListener().
-
-
-
Returns:
-
all of the PopupMenuListeners added or an empty array if no listeners have been added
-
Since:
-
1.4
firePopupMenuWillBecomeVisible
public void firePopupMenuWillBecomeVisible()
-
Notifies PopupMenuListeners that the popup portion of the combo box will become visible.
This method is public but should not be called by anything other than the UI delegate.
-
-
-
Since:
-
1.4
-
See Also:
-
addPopupMenuListener(javax.swing.event.PopupMenuListener)
firePopupMenuWillBecomeInvisible
public void firePopupMenuWillBecomeInvisible()
-
Notifies PopupMenuListeners that the popup portion of the combo box has become invisible.
This method is public but should not be called by anything other than the UI delegate.
-
-
-
Since:
-
1.4
-
See Also:
-
addPopupMenuListener(javax.swing.event.PopupMenuListener)
firePopupMenuCanceled
public void firePopupMenuCanceled()
-
Notifies PopupMenuListeners that the popup portion of the combo box has been canceled.
This method is public but should not be called by anything other than the UI delegate.
-
-
-
Since:
-
1.4
-
See Also:
-
addPopupMenuListener(javax.swing.event.PopupMenuListener)
setActionCommand
public void setActionCommand(String aCommand)
-
Sets the action command that should be included in the event sent to action listeners.
-
-
-
Parameters:
-
aCommand - a string containing the "command" that is sent to action listeners; the same listener can then do different things depending on the command it receives
getActionCommand
public String getActionCommand()
-
Returns the action command that is included in the event sent to action listeners.
-
-
-
Returns:
-
the string containing the "command" that is sent to action listeners.
setAction
public void setAction(Action a)
-
Sets the Action for the ActionEvent source. The new Action replaces any previously set Action but does not affect ActionListeners independently added with addActionListener. If the Action is already a registered ActionListener for the ActionEvent source, it is not re-registered.
A side-effect of setting the Action is that the ActionEvent source's properties are immedately set from the values in the Action (performed by the method configurePropertiesFromAction) and subsequently updated as the Action's properties change (via a PropertyChangeListener created by the method createActionPropertyChangeListener.
-
-
-
Parameters:
-
a - the Action for the JComboBox, or null.
-
Since:
-
1.3
-
See Also:
-
Action
,
getAction()
,
configurePropertiesFromAction(javax.swing.Action)
,
createActionPropertyChangeListener(javax.swing.Action)
getAction
public Action getAction()
-
Returns the currently set Action for this ActionEvent source, or null if no Action is set.
-
-
-
Returns:
-
the Action for this ActionEvent source; or null
-
Since:
-
1.3
-
See Also:
-
Action
,
setAction(javax.swing.Action)
configurePropertiesFromAction
protected void configurePropertiesFromAction(Action a)
-
Factory method which sets the ActionEvent source's properties according to values from the Action instance. The properties which are set may differ for subclasses. By default, the properties which get set are Enabled and ToolTipText.
-
-
-
Parameters:
-
a - the Action from which to get the properties, or null
-
Since:
-
1.3
-
See Also:
-
Action
,
setAction(javax.swing.Action)
createActionPropertyChangeListener
protected PropertyChangeListener createActionPropertyChangeListener(Action a)
-
Factory method which creates the PropertyChangeListener used to update the ActionEvent source as properties change on its Action instance. Subclasses may override this in order to provide their own PropertyChangeListener if the set of properties which should be kept up to date differs from the default properties (Text, Icon, Enabled, ToolTipText). Note that PropertyChangeListeners should avoid holding strong references to the ActionEvent source, as this may hinder garbage collection of the ActionEvent source and all components in its containment hierarchy.
-
-
-
Since:
-
1.3
-
See Also:
-
Action
,
setAction(javax.swing.Action)
fireItemStateChanged
protected void fireItemStateChanged(ItemEvent e)
-
Notifies all listeners that have registered interest for notification on this event type.
-
-
-
Parameters:
-
e - the event of interest
-
See Also:
-
EventListenerList
fireActionEvent
protected void fireActionEvent()
-
Notifies all listeners that have registered interest for notification on this event type.
-
-
-
See Also:
-
EventListenerList
selectedItemChanged
protected void selectedItemChanged()
-
This protected method is implementation specific. Do not access directly or override.
-
-
getSelectedObjects
public Object[] getSelectedObjects()
-
Returns an array containing the selected item. This method is implemented for compatibility with ItemSelectable.
-
-
Specified by:
-
getSelectedObjects
in interface
ItemSelectable
-
-
Returns:
-
an array of Objects containing one element -- the selected item
actionPerformed
public void actionPerformed(ActionEvent e)
-
This method is public as an implementation side effect. do not call or override.
-
-
Specified by:
-
actionPerformed
in interface
ActionListener
-
contentsChanged
public void contentsChanged(ListDataEvent e)
-
This method is public as an implementation side effect. do not call or override.
-
-
Specified by:
-
contentsChanged
in interface
ListDataListener
-
-
Parameters:
-
e - a ListDataEvent encapsulating the event information
intervalAdded
public void intervalAdded(ListDataEvent e)
-
This method is public as an implementation side effect. do not call or override.
-
-
Specified by:
-
intervalAdded
in interface
ListDataListener
-
-
Parameters:
-
e - a ListDataEvent encapsulating the event information
intervalRemoved
public void intervalRemoved(ListDataEvent e)
-
This method is public as an implementation side effect. do not call or override.
-
-
Specified by:
-
intervalRemoved
in interface
ListDataListener
-
-
Parameters:
-
e - a ListDataEvent encapsulating the event information
selectWithKeyChar
public 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. Otherwise, returns false.
-
-
-
Parameters:
-
keyChar - a char, typically this is a keyboard key typed by the user
setEnabled
public void setEnabled(boolean b)
-
Enables the combo box so that items can be selected. When the combo box is disabled, items cannot be selected and values cannot be typed into its field (if it is editable).
-
-
Overrides:
-
setEnabled
in class
JComponent
-
-
Parameters:
-
b - a boolean value, where true enables the component and false disables it
-
See Also:
-
Component.isEnabled()
,
Component.isLightweight()
configureEditor
public void configureEditor(ComboBoxEditor anEditor,
Object anItem)
-
Initializes the editor with the specified item.
-
-
-
Parameters:
-
anEditor - the ComboBoxEditor that displays the list item in the combo box field and allows it to be edited
-
anItem - the object to display and edit in the field
processKeyEvent
public void processKeyEvent(KeyEvent e)
-
Handles KeyEvents, looking for the Tab key. If the Tab key is found, the popup window is closed.
-
-
Overrides:
-
processKeyEvent
in class
JComponent
-
-
Parameters:
-
e - the KeyEvent containing the keyboard key that was pressed
-
See Also:
-
KeyEvent
,
KeyListener
,
KeyboardFocusManager
,
DefaultKeyboardFocusManager
,
Component.processEvent(java.awt.AWTEvent)
,
Component.dispatchEvent(java.awt.AWTEvent)
,
Component.addKeyListener(java.awt.event.KeyListener)
,
Component.enableEvents(long)
,
Component.isShowing()
setKeySelectionManager
public void setKeySelectionManager(JComboBox.KeySelectionManager aManager)
-
Sets the object that translates a keyboard character into a list selection. Typically, the first selection with a matching first character becomes the selected item.
-
-
getKeySelectionManager
public JComboBox.KeySelectionManager getKeySelectionManager()
-
Returns the list's key-selection manager.
-
-
-
Returns:
-
the KeySelectionManager currently in use
getItemCount
public int getItemCount()
-
Returns the number of items in the list.
-
-
-
Returns:
-
an integer equal to the number of items in the list
getItemAt
public Object getItemAt(int index)
-
Returns the list item at the specified index. If index is out of range (less than zero or greater than or equal to size) it will return null.
-
-
-
Parameters:
-
index - an integer indicating the list position, where the first item starts at zero
-
Returns:
-
the Object at that list position; or null if out of range
createDefaultKeySelectionManager
protected JComboBox.KeySelectionManager createDefaultKeySelectionManager()
-
Returns an instance of the default key-selection manager.
-
-
-
Returns:
-
the KeySelectionManager currently used by the list
-
See Also:
-
setKeySelectionManager(javax.swing.JComboBox.KeySelectionManager)
paramString
protected String paramString()
-
Returns a string representation of this JComboBox. This method is intended to be used only for debugging purposes, and the content and format of the returned string may vary between implementations. The returned string may be empty but may not be null.
-
-
Overrides:
-
paramString
in class
JComponent
-
-
Returns:
-
a string representation of this JComboBox
getAccessibleContext
public AccessibleContext getAccessibleContext()
-
Gets the AccessibleContext associated with this JComboBox. For combo boxes, the AccessibleContext takes the form of an AccessibleJComboBox. A new AccessibleJComboBox instance is created if necessary.
-
-
Specified by:
-
getAccessibleContext
in interface
Accessible
-
Overrides:
-
getAccessibleContext
in class
JComponent
-
-
Returns:
-
an AccessibleJComboBox that serves as the AccessibleContext of this JComboBox