E - the type of the elements of this combo boxpublic class JComboBox<E> extends JComponent implements ItemSelectable, ListDataListener, ActionListener, Accessible
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.
ComboBoxModel,
DefaultComboBoxModel| Modifier and Type | Class and Description |
|---|---|
protected class |
JComboBox.AccessibleJComboBox
This class implements accessibility support for the
JComboBox class. |
static interface |
JComboBox.KeySelectionManager
The interface that defines a
KeySelectionManager. |
JComponent.AccessibleJComponentContainer.AccessibleAWTContainerComponent.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy| Modifier and Type | Field and 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.
|
listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOWaccessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENTABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH| Constructor and Description |
|---|
JComboBox()
Creates a
JComboBox with a default data model. |
JComboBox(ComboBoxModel<E> aModel)
Creates a
JComboBox that takes its items from an
existing ComboBoxModel. |
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. |
| Modifier and Type | Method and 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() |
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. |
protected boolean |
processKeyBinding(KeyStroke ks,
KeyEvent e,
int condition,
boolean pressed)
Invoked to process the key bindings for
ks as the result
of the KeyEvent e. |
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.
|
addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, hide, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingOrigin, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, 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, updateadd, 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, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTreeaction, 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, 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, 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, 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, transferFocusBackward, transferFocusUpCycleprotected ComboBoxModel<E> dataModel
getModel(),
setModel(javax.swing.ComboBoxModel<E>)protected ListCellRenderer<? super E> renderer
protected ComboBoxEditor editor
getEditor(),
setEditor(javax.swing.ComboBoxEditor)protected int maximumRowCount
getMaximumRowCount(),
setMaximumRowCount(int)protected boolean isEditable
isEditable,
setEditable(boolean)protected JComboBox.KeySelectionManager keySelectionManager
protected String actionCommand
protected boolean lightWeightPopupEnabled
protected Object selectedItemReminder
public JComboBox(ComboBoxModel<E> aModel)
JComboBox that takes its 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.aModel - the ComboBoxModel that provides the
displayed list of itemsDefaultComboBoxModelpublic JComboBox(E[] items)
JComboBox that contains the elements
in the specified array. By default the first item in the array
(and therefore the data model) becomes selected.items - an array of objects to insert into the combo boxDefaultComboBoxModelpublic JComboBox(Vector<E> items)
JComboBox that contains the elements
in the specified Vector. By default the first item in the vector
(and therefore the data model) becomes selected.items - an array of vectors to insert into the combo boxDefaultComboBoxModelpublic JComboBox()
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.DefaultComboBoxModelprotected void installAncestorListener()
public void setUI(ComboBoxUI ui)
ui - the ComboBoxUI L&F objectUIDefaults.getUI(javax.swing.JComponent)public void updateUI()
updateUI in class JComponentJComponent.updateUI()public String getUIClassID()
getUIClassID in class JComponentJComponent.getUIClassID(),
UIDefaults.getUI(javax.swing.JComponent)public ComboBoxUI getUI()
public void setModel(ComboBoxModel<E> aModel)
JComboBox uses to obtain
the list of items.aModel - the ComboBoxModel that provides the
displayed list of itemspublic ComboBoxModel<E> getModel()
JComboBox.ComboBoxModel that provides the displayed
list of itemspublic void setLightWeightPopupEnabled(boolean aFlag)
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 This method fires a property changed event.
aFlag - if true, lightweight popups are desiredpublic boolean isLightWeightPopupEnabled()
lightWeightPopupEnabled
property.lightWeightPopupEnabled
propertysetLightWeightPopupEnabled(boolean)public void setEditable(boolean aFlag)
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.aFlag - a boolean value, where true indicates that the
field is editablepublic boolean isEditable()
JComboBox is editable.
By default, a combo box is not editable.JComboBox is editable, else falsepublic void setMaximumRowCount(int count)
JComboBox displays.
If the number of objects in the model is greater than count,
the combo box uses a scrollbar.count - an integer specifying the maximum number of items to
display in the list before using a scrollbarpublic int getMaximumRowCount()
public void setRenderer(ListCellRenderer<? super E> aRenderer)
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.
aRenderer - the ListCellRenderer that
displays the selected itemsetEditor(javax.swing.ComboBoxEditor)public ListCellRenderer<? super E> getRenderer()
JComboBox field.ListCellRenderer that displays
the selected item.public void setEditor(ComboBoxEditor anEditor)
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.anEditor - the ComboBoxEditor that
displays the selected itemsetRenderer(javax.swing.ListCellRenderer<? super E>)public ComboBoxEditor getEditor()
JComboBox field.ComboBoxEditor that displays the selected itempublic void setSelectedItem(Object anObject)
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.
anObject - the list object to select; use null to
clear the selectionpublic Object getSelectedItem()
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.
setSelectedItem(java.lang.Object)public void setSelectedIndex(int anIndex)
anIndex.anIndex - an integer specifying the list item to select,
where 0 specifies the first item in the list and -1 indicates no selectionIllegalArgumentException - if anIndex < -1 or
anIndex is greater than or equal to sizepublic int getSelectedIndex()
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.public E getPrototypeDisplayValue()
prototypeDisplayValue propertysetPrototypeDisplayValue(E)public void setPrototypeDisplayValue(E prototypeDisplayValue)
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.
prototypeDisplayValue - getPrototypeDisplayValue()public void addItem(E item)
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; } };
}
item - the item to add to the listMutableComboBoxModelpublic void insertItemAt(E item, int index)
JComboBox uses a
mutable data model.item - the item to add to the listindex - an integer specifying the position at which
to add the itemMutableComboBoxModelpublic void removeItem(Object anObject)
JComboBox uses a
mutable data model.anObject - the object to remove from the item listMutableComboBoxModelpublic void removeItemAt(int anIndex)
anIndex
This method works only if the JComboBox uses a
mutable data model.anIndex - an int specifying the index of the item to remove,
where 0
indicates the first item in the listMutableComboBoxModelpublic void removeAllItems()
public void showPopup()
setPopupVisible(boolean)public void hidePopup()
setPopupVisible(boolean)public void setPopupVisible(boolean v)
public boolean isPopupVisible()
public void addItemListener(ItemListener aListener)
ItemListener.
aListener will receive one or two ItemEvents when
the selected item changes.
addItemListener in interface ItemSelectableaListener - the ItemListener that is to be notifiedsetSelectedItem(java.lang.Object)public void removeItemListener(ItemListener aListener)
ItemListener.removeItemListener in interface ItemSelectableaListener - the ItemListener to removeItemEventpublic ItemListener[] getItemListeners()
ItemListeners added
to this JComboBox with addItemListener().ItemListeners added or an empty
array if no listeners have been addedpublic void addActionListener(ActionListener l)
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.
l - the ActionListener that is to be notifiedsetSelectedItem(java.lang.Object)public void removeActionListener(ActionListener l)
ActionListener.l - the ActionListener to removepublic ActionListener[] getActionListeners()
ActionListeners added
to this JComboBox with addActionListener().ActionListeners added or an empty
array if no listeners have been addedpublic void addPopupMenuListener(PopupMenuListener l)
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, 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.
l - the PopupMenuListener to addpublic void removePopupMenuListener(PopupMenuListener l)
PopupMenuListener.l - the PopupMenuListener to removeaddPopupMenuListener(javax.swing.event.PopupMenuListener)public PopupMenuListener[] getPopupMenuListeners()
PopupMenuListeners added
to this JComboBox with addPopupMenuListener().PopupMenuListeners added or an empty
array if no listeners have been addedpublic void firePopupMenuWillBecomeVisible()
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.
addPopupMenuListener(javax.swing.event.PopupMenuListener)public void firePopupMenuWillBecomeInvisible()
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.
addPopupMenuListener(javax.swing.event.PopupMenuListener)public void firePopupMenuCanceled()
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.
addPopupMenuListener(javax.swing.event.PopupMenuListener)public void setActionCommand(String aCommand)
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
receivespublic String getActionCommand()
public void setAction(Action a)
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.
Setting the Action results in immediately changing
all the properties described in
Swing Components Supporting Action.
Subsequently, the combobox's properties are automatically updated
as the Action's properties change.
This method uses three other methods to set
and help track the Action's property values.
It uses the configurePropertiesFromAction method
to immediately change the combobox's properties.
To track changes in the Action's property values,
this method registers the PropertyChangeListener
returned by createActionPropertyChangeListener. The
default PropertyChangeListener invokes the
actionPropertyChanged method when a property in the
Action changes.
a - the Action for the JComboBox,
or null.Action,
getAction(),
configurePropertiesFromAction(javax.swing.Action),
createActionPropertyChangeListener(javax.swing.Action),
actionPropertyChanged(javax.swing.Action, java.lang.String)public Action getAction()
Action for this
ActionEvent source, or null if no
Action is set.Action for this ActionEvent
source; or nullAction,
setAction(javax.swing.Action)protected void configurePropertiesFromAction(Action a)
Action. Refer to
Swing Components Supporting Action for more
details as to which properties this sets.a - the Action from which to get the properties,
or nullAction,
setAction(javax.swing.Action)protected PropertyChangeListener createActionPropertyChangeListener(Action a)
PropertyChangeListener that is
responsible for listening for changes from the specified
Action and updating the appropriate properties.
Warning: If you subclass this do not create an anonymous
inner class. If you do the lifetime of the combobox will be tied to
that of the Action.
a - the combobox's actionAction,
setAction(javax.swing.Action)protected void actionPropertyChanged(Action action, String propertyName)
PropertyChangeListener returned from
createActionPropertyChangeListener. Subclasses do not normally
need to invoke this. Subclasses that support additional Action
properties should override this and
configurePropertiesFromAction.
Refer to the table at
Swing Components Supporting Action for a list of
the properties this method sets.
action - the Action associated with this comboboxpropertyName - the name of the property that changedAction,
configurePropertiesFromAction(javax.swing.Action)protected void fireItemStateChanged(ItemEvent e)
e - the event of interestEventListenerListprotected void fireActionEvent()
EventListenerListprotected void selectedItemChanged()
public Object[] getSelectedObjects()
ItemSelectable.getSelectedObjects in interface ItemSelectableObjects containing one
element -- the selected itempublic void actionPerformed(ActionEvent e)
actionPerformed in interface ActionListenerpublic void contentsChanged(ListDataEvent e)
contentsChanged in interface ListDataListenere - a ListDataEvent encapsulating the
event informationpublic void intervalAdded(ListDataEvent e)
intervalAdded in interface ListDataListenere - a ListDataEvent encapsulating the
event informationpublic void intervalRemoved(ListDataEvent e)
intervalRemoved in interface ListDataListenere - a ListDataEvent encapsulating the
event informationpublic boolean selectWithKeyChar(char keyChar)
keyChar - a char, typically this is a keyboard key
typed by the userpublic void setEnabled(boolean b)
setEnabled in class JComponentb - a boolean value, where true enables the component and
false disables itComponent.isEnabled(),
Component.isLightweight()public void configureEditor(ComboBoxEditor anEditor, Object anItem)
anEditor - the ComboBoxEditor that displays
the list item in the
combo box field and allows it to be editedanItem - the object to display and edit in the fieldpublic void processKeyEvent(KeyEvent e)
KeyEvents, looking for the Tab key.
If the Tab key is found, the popup window is closed.processKeyEvent in class JComponente - the KeyEvent containing the keyboard
key that was pressedKeyEvent,
KeyListener,
KeyboardFocusManager,
DefaultKeyboardFocusManager,
Component.processEvent(java.awt.AWTEvent),
Component.dispatchEvent(java.awt.AWTEvent),
Component.addKeyListener(java.awt.event.KeyListener),
Component.enableEvents(long),
Component.isShowing()protected boolean processKeyBinding(KeyStroke ks, KeyEvent e, int condition, boolean pressed)
ks as the result
of the KeyEvent e. This obtains
the appropriate InputMap,
gets the binding, gets the action from the ActionMap,
and then (if the action is found and the component
is enabled) invokes notifyAction to notify the action.processKeyBinding in class JComponentks - the KeyStroke queriede - the KeyEventcondition - one of the following values:
pressed - true if the key is pressedpublic void setKeySelectionManager(JComboBox.KeySelectionManager aManager)
public JComboBox.KeySelectionManager getKeySelectionManager()
KeySelectionManager currently in usepublic int getItemCount()
public E getItemAt(int index)
index
is out of range (less than zero or greater than or equal to size)
it will return null.index - an integer indicating the list position, where the first
item starts at zeronull if out of rangeprotected JComboBox.KeySelectionManager createDefaultKeySelectionManager()
KeySelectionManager currently used by the listsetKeySelectionManager(javax.swing.JComboBox.KeySelectionManager)protected String paramString()
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.paramString in class JComponentJComboBoxpublic AccessibleContext getAccessibleContext()
getAccessibleContext in interface AccessiblegetAccessibleContext in class Component Submit a bug or feature
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