E
- the type of the elements of this combo boxActionListener
, 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
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.
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 . |
JComponent.AccessibleJComponent
Container.AccessibleAWTContainer
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
Modifier and Type | Field | Description |
---|---|---|
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. |
listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW
accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH
Constructor | Description |
---|---|
JComboBox() |
Creates a JComboBox with a default data model. |
JComboBox |
Creates a JComboBox that contains the elements in the specified array. |
JComboBox |
Creates a JComboBox that contains the elements in the specified Vector. |
JComboBox |
Creates a JComboBox that takes its items from an existing ComboBoxModel . |
Modifier and Type | Method | Description |
---|---|---|
void |
actionPerformed |
This method is public as an implementation side effect. |
protected void |
actionPropertyChanged |
Updates the combobox's state in response to property changes in associated action. |
void |
addActionListener |
Adds an ActionListener . |
void |
addItem |
Adds an item to the item list. |
void |
addItemListener |
Adds an ItemListener . |
void |
addPopupMenuListener |
Adds a PopupMenu listener which will listen to notification messages from the popup portion of the combo box. |
void |
configureEditor |
Initializes the editor with the specified item. |
protected void |
configurePropertiesFromAction |
Sets the properties on this combobox to match those in the specified Action . |
void |
contentsChanged |
This method is public as an implementation side effect. |
protected PropertyChangeListener |
createActionPropertyChangeListener |
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 |
Notifies all listeners that have registered interest for notification on this event type. |
void |
firePopupMenuCanceled() |
Notifies PopupMenuListener s that the popup portion of the combo box has been canceled. |
void |
firePopupMenuWillBecomeInvisible() |
Notifies PopupMenuListener s that the popup portion of the combo box has become invisible. |
void |
firePopupMenuWillBecomeVisible() |
Notifies PopupMenuListener s 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 ActionListener s 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 |
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 ItemListener s 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 PopupMenuListener s 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 |
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 |
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 |
This method is public as an implementation side effect. |
void |
intervalRemoved |
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 |
Handles KeyEvent s, looking for the Tab key. |
void |
removeActionListener |
Removes an ActionListener . |
void |
removeAllItems() |
Removes all items from the item list. |
void |
removeItem |
Removes an item from the item list. |
void |
removeItemAt |
Removes the item at anIndex This method works only if the JComboBox uses a mutable data model. |
void |
removeItemListener |
Removes an ItemListener . |
void |
removePopupMenuListener |
Removes a PopupMenuListener . |
protected void |
selectedItemChanged() |
This protected method is implementation specific. |
boolean |
selectWithKeyChar |
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 |
Sets the Action for the ActionEvent source. |
void |
setActionCommand |
Sets the action command that should be included in the event sent to action listeners. |
void |
setEditable |
Determines whether the JComboBox field is editable. |
void |
setEditor |
Sets the editor used to paint and edit the selected item in the JComboBox field. |
void |
setEnabled |
Enables the combo box so that items can be selected. |
void |
setKeySelectionManager |
Sets the object that translates a keyboard character into a list selection. |
void |
setLightWeightPopupEnabled |
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 |
Sets the maximum number of rows the JComboBox displays. |
void |
setModel |
Sets the data model that the JComboBox uses to obtain the list of items. |
void |
setPopupVisible |
Sets the visibility of the popup. |
void |
setPrototypeDisplayValue |
Sets the prototype display value used to calculate the size of the display for the UI portion. |
void |
setRenderer |
Sets the renderer that paints the list items and the item selected from the list in the JComboBox field. |
void |
setSelectedIndex |
Selects the item at index anIndex . |
void |
setSelectedItem |
Sets the selected item in the combo box display area to the object in the argument. |
void |
setUI |
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, 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, processKeyBinding, 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, update
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, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTree
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, 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, 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, requestFocus, requestFocus, requestFocusInWindow, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setMixingCutoutShape, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle
protected ComboBoxModel<E> dataModel
protected ListCellRenderer<? super E> renderer
protected ComboBoxEditor editor
protected int maximumRowCount
protected boolean isEditable
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 itemspublic 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 boxpublic 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 boxpublic 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.protected void installAncestorListener()
AncestorEvents
when it or any of its ancestors move or are made visible or invisible. Events are also sent when the component or its ancestors are added or removed from the containment hierarchy.@BeanProperty(hidden=true, visualUpdate=true, description="The UI object that implements the Component\'s LookAndFeel.") public void setUI(ComboBoxUI ui)
ui
- the ComboBoxUI
L&F objectpublic void updateUI()
updateUI
in class JComponent
@BeanProperty(bound=false) public String getUIClassID()
getUIClassID
in class JComponent
public ComboBoxUI getUI()
getUI
in class JComponent
@BeanProperty(description="Model that the combo box uses to get data to display.") 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 items@BeanProperty(expert=true, description="Set to <code>false</code> to require heavyweight popups.") public 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
property@BeanProperty(preferred=true, description="If true, the user can type a new value in the combo box.") 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 false@BeanProperty(preferred=true, description="The maximum number of rows the popup should have") public 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()
@BeanProperty(expert=true, description="The renderer that paints the item selected in the list.") 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 itempublic ListCellRenderer<? super E> getRenderer()
JComboBox
field.ListCellRenderer
that displays the selected item.@BeanProperty(expert=true, description="The editor that combo box uses to edit the current value") 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 itempublic ComboBoxEditor getEditor()
JComboBox
field.ComboBoxEditor
that displays the selected item@BeanProperty(bound=false, preferred=true, description="Sets the selected item in the JComboBox.") public 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, ItemListener
s added to the combo box will be notified with one or two ItemEvent
s. 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
.
ActionListener
s 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.
@BeanProperty(bound=false, preferred=true, description="The item at index is selected.") 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
property@BeanProperty(visualUpdate=true, description="The display prototype value, used to compute display width and height.") 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
- the prototype display valuepublic 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 listpublic 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 itempublic void removeItem(Object anObject)
JComboBox
uses a mutable data model.anObject
- the object to remove from the item listpublic 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 listpublic void removeAllItems()
public void showPopup()
public void hidePopup()
public void setPopupVisible(boolean v)
v
- if true
shows the popup, otherwise, hides the popup.public boolean isPopupVisible()
public void addItemListener(ItemListener aListener)
ItemListener
. aListener
will receive one or two ItemEvent
s when the selected item changes.
addItemListener
in interface ItemSelectable
aListener
- the ItemListener
that is to be notifiedpublic void removeItemListener(ItemListener aListener)
ItemListener
.removeItemListener
in interface ItemSelectable
aListener
- the ItemListener
to remove@BeanProperty(bound=false) public ItemListener[] getItemListeners()
ItemListener
s added to this JComboBox with addItemListener().ItemListener
s 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 notifiedpublic void removeActionListener(ActionListener l)
ActionListener
.l
- the ActionListener
to remove@BeanProperty(bound=false) public ActionListener[] getActionListeners()
ActionListener
s added to this JComboBox with addActionListener().ActionListener
s 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 remove@BeanProperty(bound=false) public PopupMenuListener[] getPopupMenuListeners()
PopupMenuListener
s added to this JComboBox with addPopupMenuListener().PopupMenuListener
s added or an empty array if no listeners have been addedpublic void firePopupMenuWillBecomeVisible()
PopupMenuListener
s 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.
public void firePopupMenuWillBecomeInvisible()
PopupMenuListener
s 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.
public void firePopupMenuCanceled()
PopupMenuListener
s 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.
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()
@BeanProperty(visualUpdate=true, description="the Action instance connected with this ActionEvent source") 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
.public Action getAction()
Action
for this ActionEvent
source, or null
if no Action
is set.Action
for this ActionEvent
source; or null
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 null
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 actionPropertyChangeListener
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 changedprotected void fireItemStateChanged(ItemEvent e)
e
- the event of interestprotected void fireActionEvent()
protected void selectedItemChanged()
@BeanProperty(bound=false) public Object[] getSelectedObjects()
ItemSelectable
.getSelectedObjects
in interface ItemSelectable
Objects
containing one element -- the selected itempublic void actionPerformed(ActionEvent e)
actionPerformed
in interface ActionListener
e
- the event to be processedpublic void contentsChanged(ListDataEvent e)
contentsChanged
in interface ListDataListener
e
- a ListDataEvent
encapsulating the event informationpublic void intervalAdded(ListDataEvent e)
intervalAdded
in interface ListDataListener
e
- a ListDataEvent
encapsulating the event informationpublic void intervalRemoved(ListDataEvent e)
intervalRemoved
in interface ListDataListener
e
- a ListDataEvent
encapsulating the event informationpublic boolean selectWithKeyChar(char keyChar)
keyChar
- a char, typically this is a keyboard key typed by the usertrue
if there is an item corresponding to that character. Otherwise, returns false
.@BeanProperty(preferred=true, description="The enabled state of the component.") public void setEnabled(boolean b)
setEnabled
in class JComponent
b
- a boolean value, where true enables the component and false disables itpublic 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)
KeyEvent
s, looking for the Tab key. If the Tab key is found, the popup window is closed.processKeyEvent
in class JComponent
e
- the KeyEvent
containing the keyboard key that was pressed@BeanProperty(bound=false, expert=true, description="The objects that changes the selection when a key is pressed.") public void setKeySelectionManager(JComboBox.KeySelectionManager aManager)
aManager
- a key selection managerpublic JComboBox.KeySelectionManager getKeySelectionManager()
KeySelectionManager
currently in use@BeanProperty(bound=false) public 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 listprotected 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 JComponent
JComboBox
@BeanProperty(bound=false) public AccessibleContext getAccessibleContext()
getAccessibleContext
in interface Accessible
getAccessibleContext
in class Component
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/JComboBox.html