java.awt

Class Checkbox

java.lang.Object

java.awt.Component

java.awt.Checkbox

All Implemented Interfaces:

ImageObserver, ItemSelectable, MenuContainer, Serializable, Accessible

public class Checkbox
extends Component
implements ItemSelectable, Accessible, Serializable

This class implements a component which has an on/off state. Two or more Checkboxes can be grouped by a CheckboxGroup.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	Checkbox.AccessibleAWTCheckbox This class provides accessibility support for the checkbox.

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
Checkbox() Initializes a new instance of Checkbox with no label, an initial state of off, and that is not part of any checkbox group.
Checkbox(String label) Initializes a new instance of Checkbox with the specified label, an initial state of off, and that is not part of any checkbox group.
Checkbox(String label, boolean state) Initializes a new instance of Checkbox with the specified label and initial state, and that is not part of any checkbox group.
Checkbox(String label, boolean state, CheckboxGroup group) Initializes a new instance of Checkbox with the specified label, initial state, and checkbox group.
Checkbox(String label, CheckboxGroup group, boolean state) Initializes a new instance of Checkbox with the specified label, initial state, and checkbox group.

Method Summary

Methods

Modifier and Type	Method and Description
void	addItemListener(ItemListener listener) Adds a new listeners to the list of registered listeners for this object.
void	addNotify() Creates this object's native peer.
AccessibleContext	getAccessibleContext() Gets the AccessibleContext associated with this Checkbox.
CheckboxGroup	getCheckboxGroup() Returns the checkbox group this object is a member of, if any.
ItemListener[]	getItemListeners()
String	getLabel() Returns the label for this checkbox.
Object[]	getSelectedObjects() Returns an array of length one containing the checkbox label if this checkbox is selected.
boolean	getState() Returns the state of this checkbox.
protected String	paramString() Returns a debugging string for this object.
protected void	processEvent(AWTEvent event) Processes this event by calling processItemEvent() if it is any instance of ItemEvent.
protected void	processItemEvent(ItemEvent event) Processes this event by dispatching it to any registered listeners.
void	removeItemListener(ItemListener listener) Removes a listener from the list of registered listeners for this object.
void	setCheckboxGroup(CheckboxGroup group) Sets this object's checkbox group to the specified group.
void	setLabel(String label) Sets the label for this checkbox to the specified value.
void	setState(boolean state) Sets the state of this checkbox to the specified value.

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, getListeners, 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

Checkbox

public Checkbox()

Initializes a new instance of Checkbox with no label, an initial state of off, and that is not part of any checkbox group.

Checkbox

public Checkbox(String label)

Initializes a new instance of Checkbox with the specified label, an initial state of off, and that is not part of any checkbox group.

Parameters:

label - The label for this checkbox.

Checkbox

public Checkbox(String label,
        boolean state)

Initializes a new instance of Checkbox with the specified label and initial state, and that is not part of any checkbox group.

Parameters:

label - The label for this checkbox.

state - The initial state of the checkbox, true for on, false for off.

Checkbox

public Checkbox(String label,
        CheckboxGroup group,
        boolean state)

Initializes a new instance of Checkbox with the specified label, initial state, and checkbox group.

Parameters:

label - The label for this checkbox.

group - The checkbox group for this box, or null if there is no checkbox group.

state - The initial state of the checkbox, true for on, false for off.

Checkbox

public Checkbox(String label,
        boolean state,
        CheckboxGroup group)

Initializes a new instance of Checkbox with the specified label, initial state, and checkbox group.

Parameters:

label - The label for this checkbox.

state - The initial state of the checkbox, true for on, false for off.

group - The checkbox group for this box, or null if there is no checkbox group.

Method Detail

getLabel

public String getLabel()

Returns the label for this checkbox.

Returns:

The label for this checkbox.

setLabel

public void setLabel(String label)

Sets the label for this checkbox to the specified value.

Parameters:

label - The new checkbox label.

getState

public boolean getState()

Returns the state of this checkbox.

Returns:

The state of this checkbox, which will be true for on and false for off.

setState

public void setState(boolean state)

Sets the state of this checkbox to the specified value.

Parameters:

state - The new state of the checkbox, which will be true for on or false for off.

getSelectedObjects

public Object[] getSelectedObjects()

Returns an array of length one containing the checkbox label if this checkbox is selected. Otherwise null is returned.

Specified by:

getSelectedObjects in interface ItemSelectable

Returns:

The selection state of this checkbox.

getCheckboxGroup

public CheckboxGroup getCheckboxGroup()

Returns the checkbox group this object is a member of, if any.

Returns:

This object's checkbox group, of null if it is not a member of any group.

setCheckboxGroup

public void setCheckboxGroup(CheckboxGroup group)

Sets this object's checkbox group to the specified group.

Parameters:

group - The new checkbox group, or null to make this object part of no checkbox group.

addNotify

public void addNotify()

Creates this object's native peer.

Overrides:

addNotify in class Component

See Also:

Component.isDisplayable(), Component.removeNotify()

getItemListeners

public ItemListener[] getItemListeners()

addItemListener

public void addItemListener(ItemListener listener)

Adds a new listeners to the list of registered listeners for this object.

Specified by:

addItemListener in interface ItemSelectable

Parameters:

listener - The new listener to add.

removeItemListener

public void removeItemListener(ItemListener listener)

Removes a 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 calling processItemEvent() if it is any instance of ItemEvent. Otherwise it is passed to the superclass for processing.

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 this event by dispatching it to any registered listeners.

Parameters:

event - The ItemEvent to process.

paramString

protected String paramString()

Returns a debugging string for this object.

Overrides:

paramString in class Component

Returns:

a string representing this component

getAccessibleContext

public AccessibleContext getAccessibleContext()

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

Specified by:

getAccessibleContext in interface Accessible

Overrides:

getAccessibleContext in class Component

Returns:

the associated context