java.awt
Class Choice

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Choice

All Implemented Interfaces:

Accessible, ImageObserver, ItemSelectable, MenuContainer, Serializable

public class Choice

extends Component

implements ItemSelectable, Accessible

The Choice class presents a pop-up menu of choices. The current choice is displayed as the title of the menu.

The following code example produces a pop-up menu:

 Choice ColorChooser = new Choice();
 ColorChooser.add("Green");
 ColorChooser.add("Red");
 ColorChooser.add("Blue");
 

After this choice menu has been added to a panel, it appears as follows in its normal state:

In the picture, "Green" is the current choice. Pushing the mouse button down on the object causes a menu to appear with the current choice highlighted.

Some native platforms do not support arbitrary resizing of Choice components and the behavior of setSize()/getSize() is bound by such limitations. Native GUI Choice components' size are often bound by such attributes as font size and length of items contained within the Choice.

Since:

JDK1.0

See Also:

Serialized Form

Inner Class Summary

protected class

Choice.AccessibleAWTChoice Choice.AccessibleAWTChoice This class implements accessibility support for the Choice class. It provides an implementation of the Java Accessibility API appropriate to choice user-interface elements.

Inner classes inherited from class java.awt.Component

Component.AccessibleAWTComponent

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

Choice
copy-> new Choice()
copy-> <Choice var> = new Choice();

Creates a new choice menu. The menu initially has no items in it.

By default, the first item added to the choice menu becomes the selected item, until a different selection is made by the user by calling one of the select methods.

See Also:

select(int), select(java.lang.String)

Method Summary

void	add(String item) copy-> .add( ) copy-> <Choice>.add(<String item>); Adds an item to this Choice menu. Parameters: item - the item to be added Throws: NullPointerException - if the item's value is null. Since: JDK1.1
void	addItem(String item) copy-> .addItem( ) copy-> <Choice>.addItem(<String item>); Adds an item to this Choice. Parameters: item - the item to be added Throws: NullPointerException - If the item's value is equal to null.
void	addItemListener(ItemListener l) copy-> .addItemListener( ) copy-> <Choice>.addItemListener(<ItemListener l>); Adds the specified item listener to receive item events from this Choice menu. If l is null, no exception is thrown and no action is performed. Specified by: addItemListener in interface ItemSelectable Parameters: l - the item listener. Since: JDK1.1 See Also: ItemEvent, ItemListener, removeItemListener(java.awt.event.ItemListener)
void	addNotify() copy-> .addNotify() copy-> <Choice>.addNotify(); Creates the Choice's peer. This peer allows us to change the look of the Choice without changing its functionality. Overrides: addNotify in class Component See Also: Toolkit.createChoice(java.awt.Choice), Component.getToolkit()
int	countItems() copy-> .countItems() copy-> <int var>=<Choice>.countItems(); Deprecated. As of JDK version 1.1, replaced by getItemCount().
AccessibleContext	getAccessibleContext() copy-> .getAccessibleContext() copy-> <AccessibleContext var>=<Choice>.getAccessibleContext(); Gets the AccessibleContext associated with this Choice. For Choice components, the AccessibleContext takes the form of an AccessibleAWTChoice. A new AccessibleAWTChoice instance is created if necessary. Specified by: getAccessibleContext in interface Accessible Overrides: getAccessibleContext in class Component Returns: an AccessibleAWTChoice that serves as the AccessibleContext of this Choice
String	getItem(int index) copy-> .getItem( ) copy-> <String var>=<Choice>.getItem(<int index>); Gets the string at the specified index in this Choice menu. Parameters: index - the index at which to begin. See Also: getItemCount()
int	getItemCount() copy-> .getItemCount() copy-> <int var>=<Choice>.getItemCount(); Returns the number of items in this Choice menu. Since: JDK1.1 See Also: getItem(int)
EventListener[]	getListeners(Class listenerType) copy-> .getListeners( ) copy-> <EventListener var>=<Choice>.getListeners(<Class listenerType>); Return an array of all the listeners that were added to the Choice with addXXXListener(), where XXX is the name of the listenerType argument. For example, to get all of the ItemListener(s) for the given Choice c, one would write: ItemListener[] ils = (ItemListener[])(c.getListeners(ItemListener.class)) If no such listener list exists, then an empty array is returned. Overrides: getListeners in class Component Parameters: listenerType - Type of listeners requested Returns: all of the listeners of the specified type supported by this choice Since: 1.3
int	getSelectedIndex() copy-> .getSelectedIndex() copy-> <int var>=<Choice>.getSelectedIndex(); Returns the index of the currently selected item. See Also: getSelectedItem()
String	getSelectedItem() copy-> .getSelectedItem() copy-> <String var>=<Choice>.getSelectedItem(); Gets a representation of the current choice as a string. Returns: a string representation of the currently selected item in this choice menu. See Also: getSelectedIndex()
Object[]	getSelectedObjects() copy-> .getSelectedObjects() copy-> <Object var>=<Choice>.getSelectedObjects(); Returns an array (length 1) containing the currently selected item. If this choice has no items, returns null. Specified by: getSelectedObjects in interface ItemSelectable See Also: ItemSelectable
void	insert(String item, int index) copy-> .insert(, ) copy-> <Choice>.insert(<String item>, <int index>); Inserts the item into this choice at the specified position. Parameters: item - the item to be inserted index - the position at which the item should be inserted Throws: IllegalArgumentException - if index is less than 0.
protected String	paramString() copy-> .paramString() copy-> <String var>=<Choice>.paramString(); Returns the parameter string representing the state of this choice menu. This string is useful for debugging. Overrides: paramString in class Component Returns: the parameter string of this Choice menu.
protected void	processEvent(AWTEvent e) copy-> .processEvent( ) copy-> <Choice>.processEvent(<AWTEvent e>); Processes events on this choice. If the event is an instance of ItemEvent, it invokes the processItemEvent method. Otherwise, it calls its superclass's processEvent method. Overrides: processEvent in class Component Parameters: e - the event. Since: JDK1.1 See Also: ItemEvent, processItemEvent(java.awt.event.ItemEvent)
protected void	processItemEvent(ItemEvent e) copy-> .processItemEvent( ) copy-> <Choice>.processItemEvent(<ItemEvent e>); Processes item events occurring on this Choice menu by dispatching them to any registered ItemListener objects. This method is not called unless item events are enabled for this component. Item events are enabled when one of the following occurs: An ItemListener object is registered via addItemListener. Item events are enabled via enableEvents. Parameters: e - the item event. Since: JDK1.1 See Also: ItemEvent, ItemListener, addItemListener(java.awt.event.ItemListener), Component.enableEvents(long)
void	remove(int position) copy-> .remove( ) copy-> <Choice>.remove(<int position>); Removes an item from the choice menu at the specified position. Parameters: position - the position of the item. Since: JDK1.1
void	remove(String item) copy-> .remove( ) copy-> <Choice>.remove(<String item>); Remove the first occurrence of item from the Choice menu. Parameters: item - the item to remove from this Choice menu. Throws: IllegalArgumentException - if the item doesn't exist in the choice menu. Since: JDK1.1
void	removeAll() copy-> .removeAll() copy-> <Choice>.removeAll(); Removes all items from the choice menu. Since: JDK1.1 See Also: remove(java.lang.String)
void	removeItemListener(ItemListener l) copy-> .removeItemListener( ) copy-> <Choice>.removeItemListener(<ItemListener l>); Removes the specified item listener so that it no longer receives item events from this Choice menu. If l is null, no exception is thrown and no action is performed. Specified by: removeItemListener in interface ItemSelectable Parameters: l - the item listener. Since: JDK1.1 See Also: ItemEvent, ItemListener, addItemListener(java.awt.event.ItemListener)
void	select(int pos) copy-> .select( ) copy-> <Choice>.select(<int pos>); Sets the selected item in this Choice menu to be the item at the specified position. Parameters: pos - the positon of the selected item. Throws: IllegalArgumentException - if the specified position is invalid. See Also: getSelectedItem(), getSelectedIndex()
void	select(String str) copy-> .select( ) copy-> <Choice>.select(<String str>); Sets the selected item in this Choice menu to be the item whose name is equal to the specified string. If more than one item matches (is equal to) the specified string, the one with the smallest index is selected. Parameters: str - the specified string See Also: getSelectedItem(), getSelectedIndex()

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addPropertyChangeListener, addPropertyChangeListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, deliverEvent, disable, disableEvents, dispatchEvent, doLayout, enable, enable, enableEvents, enableInputMethods, firePropertyChange, getAlignmentX, getAlignmentY, getBackground, getBounds, getBounds, getColorModel, getComponentAt, getComponentAt, getComponentOrientation, getCursor, getDropTarget, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getInputContext, getInputMethodRequests, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMinimumSize, getName, getParent, getPeer, getPreferredSize, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, invalidate, isDisplayable, isDoubleBuffered, isEnabled, isFocusTraversable, isLightweight, isOpaque, 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, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFont, setForeground, setLocale, setLocation, setLocation, setName, setSize, setSize, setVisible, show, show, size, toString, transferFocus, update, validate

Methods inherited from class java.lang.Object

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