- Type Parameters:
E
- the type of the elements of this combo box
- All Implemented Interfaces:
ActionListener
,ImageObserver
,ItemSelectable
,MenuContainer
,Serializable
,EventListener
,Accessible
,ListDataListener
@JavaBean(defaultProperty="UI", description="A combination of a text field and a drop-down list.") public class JComboBox<E> extends JComponent implements ItemSelectable, ListDataListener, ActionListener, Accessible
Warning: Swing is not thread safe. For more information see Swing's Threading Policy.
Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing. As of 1.4, support for long term storage
of all JavaBeans
has been added to the java.beans
package.
Please see XMLEncoder
.
See How to Use Combo Boxes in The Java Tutorial for further information.
- Since:
- 1.2
- See Also:
ComboBoxModel
,DefaultComboBoxModel
-
Nested Class Summary
Nested Classes Modifier and Type Class Description protected class
JComboBox.AccessibleJComboBox
This class implements accessibility support for theJComboBox
class.static interface
JComboBox.KeySelectionManager
The interface that defines aKeySelectionManager
.Nested classes/interfaces declared in class javax.swing.JComponent
JComponent.AccessibleJComponent
Nested classes/interfaces declared in class java.awt.Container
Container.AccessibleAWTContainer
Nested classes/interfaces declared in class java.awt.Component
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
-
Field Summary
Fields Modifier and Type Field Description protected String
actionCommand
This protected field is implementation specific.protected ComboBoxModel<E>
dataModel
This protected field is implementation specific.protected ComboBoxEditor
editor
This protected field is implementation specific.protected boolean
isEditable
This protected field is implementation specific.protected JComboBox.KeySelectionManager
keySelectionManager
This protected field is implementation specific.protected boolean
lightWeightPopupEnabled
This protected field is implementation specific.protected int
maximumRowCount
This protected field is implementation specific.protected ListCellRenderer<? super E>
renderer
This protected field is implementation specific.protected Object
selectedItemReminder
This protected field is implementation specific.Fields declared in class javax.swing.JComponent
listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW
Fields declared in class java.awt.Component
accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT
Fields declared in interface java.awt.image.ImageObserver
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH
-
Constructor Summary
Constructors Constructor Description JComboBox()
Creates aJComboBox
with a default data model.JComboBox(E[] items)
Creates aJComboBox
that contains the elements in the specified array.JComboBox(Vector<E> items)
Creates aJComboBox
that contains the elements in the specified Vector.JComboBox(ComboBoxModel<E> aModel)
Creates aJComboBox
that takes its items from an existingComboBoxModel
. -
Method Summary
Modifier and Type Method Description void
actionPerformed(ActionEvent e)
This method is public as an implementation side effect.protected void
actionPropertyChanged(Action action, String propertyName)
Updates the combobox's state in response to property changes in associated action.void
addActionListener(ActionListener l)
Adds anActionListener
.void
addItem(E item)
Adds an item to the item list.void
addItemListener(ItemListener aListener)
Adds anItemListener
.void
addPopupMenuListener(PopupMenuListener l)
Adds aPopupMenu
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 specifiedAction
.void
contentsChanged(ListDataEvent e)
This method is public as an implementation side effect.protected PropertyChangeListener
createActionPropertyChangeListener(Action a)
Creates and returns aPropertyChangeListener
that is responsible for listening for changes from the specifiedAction
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()
NotifiesPopupMenuListener
s that the popup portion of the combo box has been canceled.void
firePopupMenuWillBecomeInvisible()
NotifiesPopupMenuListener
s that the popup portion of the combo box has become invisible.void
firePopupMenuWillBecomeVisible()
NotifiesPopupMenuListener
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 setAction
for thisActionEvent
source, ornull
if noAction
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 theActionListener
s added to this JComboBox with addActionListener().ComboBoxEditor
getEditor()
Returns the editor used to paint and edit the selected item in theJComboBox
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 theItemListener
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 scrollbarComboBoxModel<E>
getModel()
Returns the data model currently used by theJComboBox
.PopupMenuListener[]
getPopupMenuListeners()
Returns an array of all thePopupMenuListener
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<? super E>
getRenderer()
Returns the renderer used to display the selected item in theJComboBox
field.int
getSelectedIndex()
Returns the first item in the list that matches the given item.Object
getSelectedItem()
Returns the current selected item.Object[]
getSelectedObjects()
Returns an array containing the selected item.ComboBoxUI
getUI()
Returns the L&F object that renders this component.String
getUIClassID()
Returns the name of the L&F class that renders this component.void
hidePopup()
Causes the combo box to close its popup window.void
insertItemAt(E item, int index)
Inserts an item into the item list at a given index.protected void
installAncestorListener()
Registers ancestor listener so that it will receiveAncestorEvents
when it or any of its ancestors move or are made visible or invisible.void
intervalAdded(ListDataEvent e)
This method is public as an implementation side effect.void
intervalRemoved(ListDataEvent e)
This method is public as an implementation side effect.boolean
isEditable()
Returns true if theJComboBox
is editable.boolean
isLightWeightPopupEnabled()
Gets the value of thelightWeightPopupEnabled
property.boolean
isPopupVisible()
Determines the visibility of the popup.protected String
paramString()
Returns a string representation of thisJComboBox
.void
processKeyEvent(KeyEvent e)
HandlesKeyEvent
s, looking for the Tab key.void
removeActionListener(ActionListener l)
Removes anActionListener
.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 atanIndex
This method works only if theJComboBox
uses a mutable data model.void
removeItemListener(ItemListener aListener)
Removes anItemListener
.void
removePopupMenuListener(PopupMenuListener l)
Removes aPopupMenuListener
.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 theAction
for theActionEvent
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 theJComboBox
field is editable.void
setEditor(ComboBoxEditor anEditor)
Sets the editor used to paint and edit the selected item in theJComboBox
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 thelightWeightPopupEnabled
property, which provides a hint as to whether or not a lightweightComponent
should be used to contain theJComboBox
, versus a heavyweightComponent
such as aPanel
or aWindow
.void
setMaximumRowCount(int count)
Sets the maximum number of rows theJComboBox
displays.void
setModel(ComboBoxModel<E> aModel)
Sets the data model that theJComboBox
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 indexanIndex
.void
setSelectedItem(Object anObject)
Sets the selected item in the combo box display area to the object in the argument.void
setUI(ComboBoxUI ui)
Sets the L&F object that renders this component.void
showPopup()
Causes the combo box to display its popup window.void
updateUI()
Resets the UI property to a value from the current look and feel.Methods declared in class javax.swing.JComponent
addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, 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
Methods declared in 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, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusDownCycle, validate, validateTree
Methods declared in 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, 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
-
Field Details
-
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<E>)
-
renderer
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead. -
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 maximumRowCountThis protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.- See Also:
getMaximumRowCount()
,setMaximumRowCount(int)
-
isEditable
protected boolean isEditableThis protected field is implementation specific. Do not access directly or override. Use the accessor methods instead.- See Also:
isEditable
,setEditable(boolean)
-
keySelectionManager
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead. -
actionCommand
This protected field is implementation specific. Do not access directly or override. Use the accessor methods instead. -
lightWeightPopupEnabled
protected boolean lightWeightPopupEnabledThis protected field is implementation specific. Do not access directly or override. Use the accessor methods instead. -
selectedItemReminder
This protected field is implementation specific. Do not access directly or override.
-
-
Constructor Details
-
JComboBox
Creates aJComboBox
that takes its items from an existingComboBoxModel
. Since theComboBoxModel
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
- theComboBoxModel
that provides the displayed list of items- See Also:
DefaultComboBoxModel
-
JComboBox
Creates aJComboBox
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
Creates aJComboBox
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 aJComboBox
with a default data model. The default data model is an empty list of objects. UseaddItem
to add items. By default the first item in the data model becomes selected.- See Also:
DefaultComboBoxModel
-
-
Method Details
-
installAncestorListener
protected void installAncestorListener()Registers ancestor listener so that it will receiveAncestorEvents
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. -
setUI
@BeanProperty(hidden=true, visualUpdate=true, description="The UI object that implements the Component\'s LookAndFeel.") public void setUI(ComboBoxUI ui)Sets the L&F object that renders this component.- Parameters:
ui
- theComboBoxUI
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 classJComponent
- See Also:
JComponent.updateUI()
-
getUIClassID
Returns the name of the L&F class that renders this component.- Overrides:
getUIClassID
in classJComponent
- Returns:
- the string "ComboBoxUI"
- See Also:
JComponent.getUIClassID()
,UIDefaults.getUI(javax.swing.JComponent)
-
getUI
Returns the L&F object that renders this component.- Overrides:
getUI
in classJComponent
- Returns:
- the ComboBoxUI object that renders this component
-
setModel
@BeanProperty(description="Model that the combo box uses to get data to display.") public void setModel(ComboBoxModel<E> aModel)Sets the data model that theJComboBox
uses to obtain the list of items.- Parameters:
aModel
- theComboBoxModel
that provides the displayed list of items
-
getModel
Returns the data model currently used by theJComboBox
.- Returns:
- the
ComboBoxModel
that provides the displayed list of items
-
setLightWeightPopupEnabled
@BeanProperty(expert=true, description="Set to <code>false</code> to require heavyweight popups.") public void setLightWeightPopupEnabled(boolean aFlag)Sets thelightWeightPopupEnabled
property, which provides a hint as to whether or not a lightweightComponent
should be used to contain theJComboBox
, versus a heavyweightComponent
such as aPanel
or aWindow
. The decision of lightweight versus heavyweight is ultimately up to theJComboBox
. 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 thelightWeightPopupEnabled
property istrue
, 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.
- Parameters:
aFlag
- iftrue
, lightweight popups are desired
-
isLightWeightPopupEnabled
public boolean isLightWeightPopupEnabled()Gets the value of thelightWeightPopupEnabled
property.- Returns:
- the value of the
lightWeightPopupEnabled
property - See Also:
setLightWeightPopupEnabled(boolean)
-
setEditable
@BeanProperty(preferred=true, description="If true, the user can type a new value in the combo box.") public void setEditable(boolean aFlag)Determines whether theJComboBox
field is editable. An editableJComboBox
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 editableJComboBox
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 theJComboBox
is editable. By default, a combo box is not editable.- Returns:
- true if the
JComboBox
is editable, else false
-
setMaximumRowCount
@BeanProperty(preferred=true, description="The maximum number of rows the popup should have") public void setMaximumRowCount(int count)Sets the maximum number of rows theJComboBox
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
@BeanProperty(expert=true, description="The renderer that paints the item selected in the list.") public 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. 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
- theListCellRenderer
that displays the selected item- See Also:
setEditor(javax.swing.ComboBoxEditor)
-
getRenderer
Returns the renderer used to display the selected item in theJComboBox
field.- Returns:
- the
ListCellRenderer
that displays the selected item.
-
setEditor
@BeanProperty(expert=true, description="The editor that combo box uses to edit the current value") public void setEditor(ComboBoxEditor anEditor)Sets the editor used to paint and edit the selected item in theJComboBox
field. The editor is used only if the receivingJComboBox
is editable. If not editable, the combo box uses the renderer to paint the selected item.- Parameters:
anEditor
- theComboBoxEditor
that displays the selected item- See Also:
setRenderer(javax.swing.ListCellRenderer<? super E>)
-
getEditor
Returns the editor used to paint and edit the selected item in theJComboBox
field.- Returns:
- the
ComboBoxEditor
that displays the selected item
-
setSelectedItem
@BeanProperty(bound=false, preferred=true, description="Sets the selected item in the JComboBox.") public void setSelectedItem(Object anObject)Sets the selected item in the combo box display area to the object in the argument. IfanObject
is in the list, the display area showsanObject
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 toanObject
.If this constitutes a change in the selected item,
ItemListener
s added to the combo box will be notified with one or twoItemEvent
s. If there is a current selected item, anItemEvent
will be fired and the state change will beItemEvent.DESELECTED
. IfanObject
is in the list and is not currently selected then anItemEvent
will be fired and the state change will beItemEvent.SELECTED
.ActionListener
s added to the combo box will be notified with anActionEvent
when this method is called.- Parameters:
anObject
- the list object to select; usenull
to clear the selection
-
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
@BeanProperty(bound=false, preferred=true, description="The item at index is selected.") public void setSelectedIndex(int anIndex)Selects the item at indexanIndex
.- 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
- ifanIndex
< -1 oranIndex
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 theJComboBox
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
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(E)
-
setPrototypeDisplayValue
@BeanProperty(visualUpdate=true, description="The display prototype value, used to compute display width and height.") public void setPrototypeDisplayValue(E 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
- the prototype display value- Since:
- 1.4
- See Also:
getPrototypeDisplayValue()
-
addItem
Adds an item to the item list. This method works only if theJComboBox
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:
item
- the item to add to the list- See Also:
MutableComboBoxModel
-
insertItemAt
Inserts an item into the item list at a given index. This method works only if theJComboBox
uses a mutable data model.- Parameters:
item
- the item to add to the listindex
- an integer specifying the position at which to add the item- See Also:
MutableComboBoxModel
-
removeItem
Removes an item from the item list. This method works only if theJComboBox
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 atanIndex
This method works only if theJComboBox
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.- Parameters:
v
- iftrue
shows the popup, otherwise, hides the popup.
-
isPopupVisible
public boolean isPopupVisible()Determines the visibility of the popup.- Returns:
- true if the popup is visible, otherwise returns false
-
addItemListener
Adds anItemListener
.aListener
will receive one or twoItemEvent
s when the selected item changes.- Specified by:
addItemListener
in interfaceItemSelectable
- Parameters:
aListener
- theItemListener
that is to be notified- See Also:
setSelectedItem(java.lang.Object)
-
removeItemListener
Removes anItemListener
.- Specified by:
removeItemListener
in interfaceItemSelectable
- Parameters:
aListener
- theItemListener
to remove- See Also:
ItemEvent
-
getItemListeners
Returns an array of all theItemListener
s added to this JComboBox with addItemListener().- Returns:
- all of the
ItemListener
s added or an empty array if no listeners have been added - Since:
- 1.4
-
addActionListener
Adds anActionListener
.The
ActionListener
will receive anActionEvent
when a selection has been made. If the combo box is editable, then anActionEvent
will be fired when editing has stopped.- Parameters:
l
- theActionListener
that is to be notified- See Also:
setSelectedItem(java.lang.Object)
-
removeActionListener
Removes anActionListener
.- Parameters:
l
- theActionListener
to remove
-
getActionListeners
Returns an array of all theActionListener
s added to this JComboBox with addActionListener().- Returns:
- all of the
ActionListener
s added or an empty array if no listeners have been added - Since:
- 1.4
-
addPopupMenuListener
Adds aPopupMenu
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.- Parameters:
l
- thePopupMenuListener
to add- Since:
- 1.4
-
removePopupMenuListener
Removes aPopupMenuListener
.- Parameters:
l
- thePopupMenuListener
to remove- Since:
- 1.4
- See Also:
addPopupMenuListener(javax.swing.event.PopupMenuListener)
-
getPopupMenuListeners
Returns an array of all thePopupMenuListener
s added to this JComboBox with addPopupMenuListener().- Returns:
- all of the
PopupMenuListener
s added or an empty array if no listeners have been added - Since:
- 1.4
-
firePopupMenuWillBecomeVisible
public void firePopupMenuWillBecomeVisible()NotifiesPopupMenuListener
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.
- Since:
- 1.4
- See Also:
addPopupMenuListener(javax.swing.event.PopupMenuListener)
-
firePopupMenuWillBecomeInvisible
public void firePopupMenuWillBecomeInvisible()NotifiesPopupMenuListener
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.
- Since:
- 1.4
- See Also:
addPopupMenuListener(javax.swing.event.PopupMenuListener)
-
firePopupMenuCanceled
public void firePopupMenuCanceled()NotifiesPopupMenuListener
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.
- Since:
- 1.4
- See Also:
addPopupMenuListener(javax.swing.event.PopupMenuListener)
-
setActionCommand
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
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
@BeanProperty(visualUpdate=true, description="the Action instance connected with this ActionEvent source") public void setAction(Action a)Sets theAction
for theActionEvent
source. The newAction
replaces any previously setAction
but does not affectActionListeners
independently added withaddActionListener
. If theAction
is already a registeredActionListener
for theActionEvent
source, it is not re-registered.Setting the
Action
results in immediately changing all the properties described in Swing Components SupportingAction
. Subsequently, the combobox's properties are automatically updated as theAction
's properties change.This method uses three other methods to set and help track the
Action
's property values. It uses theconfigurePropertiesFromAction
method to immediately change the combobox's properties. To track changes in theAction
's property values, this method registers thePropertyChangeListener
returned bycreateActionPropertyChangeListener
. The defaultPropertyChangeListener
invokes theactionPropertyChanged
method when a property in theAction
changes.- Parameters:
a
- theAction
for theJComboBox
, ornull
.- Since:
- 1.3
- See Also:
Action
,getAction()
,configurePropertiesFromAction(javax.swing.Action)
,createActionPropertyChangeListener(javax.swing.Action)
,actionPropertyChanged(javax.swing.Action, java.lang.String)
-
getAction
Returns the currently setAction
for thisActionEvent
source, ornull
if noAction
is set.- Returns:
- the
Action
for thisActionEvent
source; ornull
- Since:
- 1.3
- See Also:
Action
,setAction(javax.swing.Action)
-
configurePropertiesFromAction
Sets the properties on this combobox to match those in the specifiedAction
. Refer to Swing Components SupportingAction
for more details as to which properties this sets.- Parameters:
a
- theAction
from which to get the properties, ornull
- Since:
- 1.3
- See Also:
Action
,setAction(javax.swing.Action)
-
createActionPropertyChangeListener
Creates and returns aPropertyChangeListener
that is responsible for listening for changes from the specifiedAction
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
.- Parameters:
a
- the combobox's action- Returns:
- the
PropertyChangeListener
- Since:
- 1.3
- See Also:
Action
,setAction(javax.swing.Action)
-
actionPropertyChanged
Updates the combobox's state in response to property changes in associated action. This method is invoked from thePropertyChangeListener
returned fromcreateActionPropertyChangeListener
. Subclasses do not normally need to invoke this. Subclasses that support additionalAction
properties should override this andconfigurePropertiesFromAction
.Refer to the table at Swing Components Supporting
Action
for a list of the properties this method sets.- Parameters:
action
- theAction
associated with this comboboxpropertyName
- the name of the property that changed- Since:
- 1.6
- See Also:
Action
,configurePropertiesFromAction(javax.swing.Action)
-
fireItemStateChanged
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
Returns an array containing the selected item. This method is implemented for compatibility withItemSelectable
.- Specified by:
getSelectedObjects
in interfaceItemSelectable
- Returns:
- an array of
Objects
containing one element -- the selected item
-
actionPerformed
This method is public as an implementation side effect. do not call or override.- Specified by:
actionPerformed
in interfaceActionListener
- Parameters:
e
- the event to be processed
-
contentsChanged
This method is public as an implementation side effect. do not call or override.- Specified by:
contentsChanged
in interfaceListDataListener
- Parameters:
e
- aListDataEvent
encapsulating the event information
-
intervalAdded
This method is public as an implementation side effect. do not call or override.- Specified by:
intervalAdded
in interfaceListDataListener
- Parameters:
e
- aListDataEvent
encapsulating the event information
-
intervalRemoved
This method is public as an implementation side effect. do not call or override.- Specified by:
intervalRemoved
in interfaceListDataListener
- Parameters:
e
- aListDataEvent
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- Returns:
true
if there is an item corresponding to that character. Otherwise, returnsfalse
.
-
setEnabled
@BeanProperty(preferred=true, description="The enabled state of the component.") 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 classJComponent
- Parameters:
b
- a boolean value, where true enables the component and false disables it- See Also:
Component.isEnabled()
,Component.isLightweight()
-
configureEditor
Initializes the editor with the specified item.- Parameters:
anEditor
- theComboBoxEditor
that displays the list item in the combo box field and allows it to be editedanItem
- the object to display and edit in the field
-
processKeyEvent
HandlesKeyEvent
s, looking for the Tab key. If the Tab key is found, the popup window is closed.- Overrides:
processKeyEvent
in classJComponent
- Parameters:
e
- theKeyEvent
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
@BeanProperty(bound=false, expert=true, description="The objects that changes the selection when a key is pressed.") 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.- Parameters:
aManager
- a key selection manager
-
getKeySelectionManager
Returns the list's key-selection manager.- Returns:
- the
KeySelectionManager
currently in use
-
getItemCount
Returns the number of items in the list.- Returns:
- an integer equal to the number of items in the list
-
getItemAt
Returns the list item at the specified index. Ifindex
is out of range (less than zero or greater than or equal to size) it will returnnull
.- Parameters:
index
- an integer indicating the list position, where the first item starts at zero- Returns:
- the item at that list position; or
null
if out of range
-
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
Returns a string representation of thisJComboBox
. 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 benull
.- Overrides:
paramString
in classJComponent
- Returns:
- a string representation of this
JComboBox
-
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 interfaceAccessible
- Overrides:
getAccessibleContext
in classComponent
- Returns:
- an AccessibleJComboBox that serves as the AccessibleContext of this JComboBox
-