java.awt

Class Choice

java.lang.Object

java.awt.Component

java.awt.Choice

All Implemented Interfaces:

ImageObserver, ItemSelectable, MenuContainer, Serializable, Accessible

public class Choice
extends Component
implements ItemSelectable, Serializable, Accessible

This class implements a drop down choice list.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	Choice.AccessibleAWTChoice This class provides accessibility support for the combo box.

Nested classes/interfaces inherited from class java.awt.Component

Component.AccessibleAWTComponent, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

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

Constructor Summary

Constructors

Constructor and Description
Choice() Initializes a new instance of Choice.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(String item) Adds the specified item to this choice box.
void	addItem(String item) Adds the specified item to this choice box.
void	addItemListener(ItemListener listener) Adds the specified listener to the list of registered listeners for this object.
void	addNotify() Creates the native peer for this object.
int	countItems() Deprecated. This method is deprecated in favor of getItemCount.
AccessibleContext	getAccessibleContext() Gets the AccessibleContext associated with this Choice.
String	getItem(int index) Returns the item at the specified index in the list.
int	getItemCount() Returns the number of items in the list.
ItemListener[]	getItemListeners() Returns all registered item listeners.
<T extends EventListener> T[]	getListeners(Class<T> listenerType) Returns an array of all the objects currently registered as FooListeners upon this Choice.
int	getSelectedIndex() Returns the index of the selected item.
String	getSelectedItem() Returns the currently selected item, or null if no item is selected.
Object[]	getSelectedObjects() Returns an array with one row containing the selected item.
void	insert(String item, int index) Inserts an item into this Choice.
protected String	paramString() Returns a debugging string for this object.
protected void	processEvent(AWTEvent event) Processes this event by invoking processItemEvent() if the event is an instance of ItemEvent, otherwise the event is passed to the superclass.
protected void	processItemEvent(ItemEvent event) Processes item event by dispatching to any registered listeners.
void	remove(int index) Removes the item at the specified index from the choice box.
void	remove(String item) Removes the specified item from the choice box.
void	removeAll() Removes all of the objects from this choice box.
void	removeItemListener(ItemListener listener) Removes the specified listener from the list of registered listeners for this object.
void	select(int index) Forces the item at the specified index to be selected.
void	select(String item) Forces the named item to be selected.

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, deliverEvent, disable, disableEvents, dispatchEvent, doLayout, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getAlignmentX, getAlignmentY, getBackground, getBounds, getBounds, getColorModel, getComponentAt, getComponentAt, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeys, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMinimumSize, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, invalidate, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusCycleRoot, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, layout, list, list, list, list, list, locate, location, lostFocus, minimumSize, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paint, paintAll, postEvent, preferredSize, prepareImage, prepareImage, print, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Choice

public Choice()

Initializes a new instance of Choice.

Throws:

HeadlessException - If GraphicsEnvironment.isHeadless() returns true

Method Detail

getItemCount

public int getItemCount()

Returns the number of items in the list.

Returns:

The number of items in the list.

countItems

public int countItems()

Deprecated. This method is deprecated in favor of getItemCount.

Returns the number of items in the list.

Returns:

The number of items in the list.

getItem

public String getItem(int index)

Returns the item at the specified index in the list.

Parameters:

index - The index into the list to return the item from.

Throws:

ArrayIndexOutOfBoundsException - If the index is invalid.

add

public void add(String item)

Adds the specified item to this choice box.

Parameters:

item - The item to add.

Throws:

NullPointerException - If the item's value is null

Since:

1.1

addItem

public void addItem(String item)

Adds the specified item to this choice box. This method is oboslete since Java 2 platform 1.1. Please use add(String) instead.

Parameters:

item - The item to add.

Throws:

NullPointerException - If the item's value is equal to null

insert

public void insert(String item,
          int index)

Inserts an item into this Choice. Existing items are shifted upwards. If the new item is the only item, then it is selected. If the currently selected item is shifted, then the first item is selected. If the currently selected item is not shifted, then it remains selected.

Parameters:

item - The item to add.

index - The index at which the item should be inserted.

Throws:

IllegalArgumentException - If index is less than 0

remove

public void remove(String item)

Removes the specified item from the choice box.

Parameters:

item - The item to remove.

Throws:

IllegalArgumentException - If the specified item doesn't exist.

remove

public void remove(int index)

Removes the item at the specified index from the choice box.

Parameters:

index - The index of the item to remove.

Throws:

IndexOutOfBoundsException - If the index is not valid.

removeAll

public void removeAll()

Removes all of the objects from this choice box.

getSelectedItem

public String getSelectedItem()

Returns the currently selected item, or null if no item is selected.

Returns:

The currently selected item.

getSelectedObjects

public Object[] getSelectedObjects()

Returns an array with one row containing the selected item.

Specified by:

getSelectedObjects in interface ItemSelectable

Returns:

An array containing the selected item.

getSelectedIndex

public int getSelectedIndex()

Returns the index of the selected item.

Returns:

The index of the selected item.

select

public void select(int index)

Forces the item at the specified index to be selected.

Parameters:

index - The index of the row to make selected.

Throws:

IllegalArgumentException - If the specified index is invalid.

select

public void select(String item)

Forces the named item to be selected.

Parameters:

item - The item to be selected.

Throws:

IllegalArgumentException - If the specified item does not exist.

addNotify

public void addNotify()

Creates the native peer for this object.

Overrides:

addNotify in class Component

See Also:

Component.isDisplayable(), Component.removeNotify()

addItemListener

public void addItemListener(ItemListener listener)

Adds the specified listener to the list of registered listeners for this object.

Specified by:

addItemListener in interface ItemSelectable

Parameters:

listener - The listener to add.

removeItemListener

public void removeItemListener(ItemListener listener)

Removes the specified listener from the list of registered listeners for this object.

Specified by:

removeItemListener in interface ItemSelectable

Parameters:

listener - The listener to remove.

processEvent

protected void processEvent(AWTEvent event)

Processes this event by invoking processItemEvent() if the event is an instance of ItemEvent, otherwise the event is passed to the superclass.

Overrides:

processEvent in class Component

Parameters:

event - The event to process.

See Also:

Component.processComponentEvent(ComponentEvent), Component.processFocusEvent(FocusEvent), Component.processKeyEvent(KeyEvent), Component.processMouseEvent(MouseEvent), Component.processMouseMotionEvent(MouseEvent), Component.processInputMethodEvent(InputMethodEvent), Component.processHierarchyEvent(HierarchyEvent), Component.processMouseWheelEvent(MouseWheelEvent)

processItemEvent

protected void processItemEvent(ItemEvent event)

Processes item event by dispatching to any registered listeners.

Parameters:

event - The event to process.

paramString

protected String paramString()

Returns a debugging string for this object.

Overrides:

paramString in class Component

Returns:

A debugging string for this object.

getListeners

public <T extends EventListener> T[] getListeners(Class<T> listenerType)

Returns an array of all the objects currently registered as FooListeners upon this Choice. FooListeners are registered using the addFooListener method.

Overrides:

getListeners in class Component

Parameters:

listenerType - the class of listeners to filter (null not permitted).

Returns:

An array of registered listeners.

Throws:

ClassCastException - If listenerType doesn't specify a class or interface that implements java.util.EventListener.

Since:

1.3

See Also:

Component.getComponentListeners(), Component.getFocusListeners(), Component.getHierarchyListeners(), Component.getHierarchyBoundsListeners(), Component.getKeyListeners(), Component.getMouseListeners(), Component.getMouseMotionListeners(), Component.getMouseWheelListeners(), Component.getInputMethodListeners(), Component.getPropertyChangeListeners()

getItemListeners

public ItemListener[] getItemListeners()

Returns all registered item listeners.

Since:

1.4

getAccessibleContext

public AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this Choice. The context is created, if necessary.

Specified by:

getAccessibleContext in interface Accessible

Overrides:

getAccessibleContext in class Component

Returns:

the associated context