Checkbox (Java SE 26 & JDK 26)
Description: declaration: module: java.desktop, package: java.awt, class: Checkbox
Keywords: java.awt.Checkbox class

# 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
A check box is a graphical component that can be in either an "on" (`true`) or "off" (`false`) state. Clicking on a check box changes its state from "on" to "off," or from "off" to "on."

The following code example creates a set of check boxes in a grid layout:

>     setLayout(new GridLayout(3, 1));
>     add(new Checkbox("one", null, true));
>     add(new Checkbox("two"));
>     add(new Checkbox("three"));

This image depicts the check boxes and grid layout created by this code example:

The button labeled `one` is in the "on" state, and the other two are in the "off" state. In this example, which uses the `GridLayout` class, the states of the three check boxes are set independently.

Alternatively, several check boxes can be grouped together under the control of a single object, using the `CheckboxGroup` class. In a check box group, at most one button can be in the "on" state at any given time. Clicking on a check box to turn it on forces any other check box in the same group that is on into the "off" state.

Since:
  1.0
See Also:
  - `GridLayout`
  - `CheckboxGroup`
  - Serialized Form

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `protected class`
  `Checkbox.AccessibleAWTCheckbox`
  This class implements accessibility support for the `Checkbox` class.

  ### Nested classes/interfaces declared in class Component

  `Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy`
  Modifier and Type
  Class
  Description
  `protected class`
  `Component.AccessibleAWTComponent`
  Inner class of Component used to provide default support for accessibility.
  `static enum`
  `Component.BaselineResizeBehavior`
  Enumeration of the common ways the baseline of a component can change as the size changes.
  `protected class`
  `Component.BltBufferStrategy`
  Inner class for blitting offscreen surfaces to a component.
  `protected class`
  `Component.FlipBufferStrategy`
  Inner class for flipping buffers on a component.

- ## Field Summary

  ### Fields declared in class Component

  `accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT`
  Modifier and Type
  Field
  Description
  `protected AccessibleContext`
  `accessibleContext`
  The `AccessibleContext` associated with this `Component`.
  `static final float`
  `BOTTOM_ALIGNMENT`
  Ease-of-use constant for `getAlignmentY`.
  `static final float`
  `CENTER_ALIGNMENT`
  Ease-of-use constant for `getAlignmentY` and `getAlignmentX`.
  `static final float`
  `LEFT_ALIGNMENT`
  Ease-of-use constant for `getAlignmentX`.
  `static final float`
  `RIGHT_ALIGNMENT`
  Ease-of-use constant for `getAlignmentX`.
  `static final float`
  `TOP_ALIGNMENT`
  Ease-of-use constant for `getAlignmentY()`.

  ### Fields declared in interface ImageObserver

  `ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH`
  Modifier and Type
  Field
  Description
  `static final int`
  `ABORT`
  This flag in the infoflags argument to imageUpdate indicates that an image which was being tracked asynchronously was aborted before production was complete.
  `static final int`
  `ALLBITS`
  This flag in the infoflags argument to imageUpdate indicates that a static image which was previously drawn is now complete and can be drawn again in its final form.
  `static final int`
  `ERROR`
  This flag in the infoflags argument to imageUpdate indicates that an image which was being tracked asynchronously has encountered an error.
  `static final int`
  `FRAMEBITS`
  This flag in the infoflags argument to imageUpdate indicates that another complete frame of a multi-frame image which was previously drawn is now available to be drawn again.
  `static final int`
  `HEIGHT`
  This flag in the infoflags argument to imageUpdate indicates that the height of the base image is now available and can be taken from the height argument to the imageUpdate callback method.
  `static final int`
  `PROPERTIES`
  This flag in the infoflags argument to imageUpdate indicates that the properties of the image are now available.
  `static final int`
  `SOMEBITS`
  This flag in the infoflags argument to imageUpdate indicates that more pixels needed for drawing a scaled variation of the image are available.
  `static final int`
  `WIDTH`
  This flag in the infoflags argument to imageUpdate indicates that the width of the base image is now available and can be taken from the width argument to the imageUpdate callback method.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `Checkbox()`
  Creates a check box with an empty string for its label.
  `Checkbox(String label)`
  Creates a check box with the specified label.
  `Checkbox(String label, boolean state)`
  Creates a check box with the specified label and sets the specified state.
  `Checkbox(String label, boolean state, CheckboxGroup group)`
  Constructs a Checkbox with the specified label, set to the specified state, and in the specified check box group.
  `Checkbox(String label, CheckboxGroup group, boolean state)`
  Creates a check box with the specified label, in the specified check box group, and set to the specified state.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `addItemListener(ItemListener l)`
  Adds the specified item listener to receive item events from this check box.
  `void`
  `addNotify()`
  Creates the peer of the Checkbox.
  `AccessibleContext`
  `getAccessibleContext()`
  Gets the AccessibleContext associated with this Checkbox.
  `CheckboxGroup`
  `getCheckboxGroup()`
  Determines this check box's group.
  `ItemListener[]`
  `getItemListeners()`
  Returns an array of all the item listeners registered on this checkbox.
  `String`
  `getLabel()`
  Gets the label of this check box.
  `<T extends EventListener>
  T[]`
  `getListeners(Class<T> listenerType)`
  Returns an array of all the objects currently registered as `FooListener`s upon this `Checkbox`.
  `Object[]`
  `getSelectedObjects()`
  Returns an array (length 1) containing the checkbox label or null if the checkbox is not selected.
  `boolean`
  `getState()`
  Determines whether this check box is in the "on" or "off" state.
  `protected String`
  `paramString()`
  Returns a string representing the state of this `Checkbox`.
  `protected void`
  `processEvent(AWTEvent e)`
  Processes events on this check box.
  `protected void`
  `processItemEvent(ItemEvent e)`
  Processes item events occurring on this check box by dispatching them to any registered `ItemListener` objects.
  `void`
  `removeItemListener(ItemListener l)`
  Removes the specified item listener so that the item listener no longer receives item events from this check box.
  `void`
  `setCheckboxGroup(CheckboxGroup g)`
  Sets this check box's group to the specified check box group.
  `void`
  `setLabel(String label)`
  Sets this check box's label to be the string argument.
  `void`
  `setState(boolean state)`
  Sets the state of this check box to the specified state.

  ### Methods declared in class 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, getBaseline, getBaselineResizeBehavior, 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, 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, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setMixingCutoutShape, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate`
  Modifier and Type
  Method
  Description
  `boolean`
  `action(Event evt, Object what)`
  Deprecated.
  As of JDK version 1.1, should register this component as ActionListener on component which fires action events.
  `void`
  `add(PopupMenu popup)`
  Adds the specified popup menu to the component.
  `void`
  `addComponentListener(ComponentListener l)`
  Adds the specified component listener to receive component events from this component.
  `void`
  `addFocusListener(FocusListener l)`
  Adds the specified focus listener to receive focus events from this component when this component gains input focus.
  `void`
  `addHierarchyBoundsListener(HierarchyBoundsListener l)`
  Adds the specified hierarchy bounds listener to receive hierarchy bounds events from this component when the hierarchy to which this container belongs changes.
  `void`
  `addHierarchyListener(HierarchyListener l)`
  Adds the specified hierarchy listener to receive hierarchy changed events from this component when the hierarchy to which this container belongs changes.
  `void`
  `addInputMethodListener(InputMethodListener l)`
  Adds the specified input method listener to receive input method events from this component.
  `void`
  `addKeyListener(KeyListener l)`
  Adds the specified key listener to receive key events from this component.
  `void`
  `addMouseListener(MouseListener l)`
  Adds the specified mouse listener to receive mouse events from this component.
  `void`
  `addMouseMotionListener(MouseMotionListener l)`
  Adds the specified mouse motion listener to receive mouse motion events from this component.
  `void`
  `addMouseWheelListener(MouseWheelListener l)`
  Adds the specified mouse wheel listener to receive mouse wheel events from this component.
  `void`
  `addPropertyChangeListener(PropertyChangeListener listener)`
  Adds a PropertyChangeListener to the listener list.
  `void`
  `addPropertyChangeListener(String propertyName, PropertyChangeListener listener)`
  Adds a PropertyChangeListener to the listener list for a specific property.
  `void`
  `applyComponentOrientation(ComponentOrientation orientation)`
  Sets the `ComponentOrientation` property of this component and all components contained within it.
  `boolean`
  `areFocusTraversalKeysSet(int id)`
  Returns whether the Set of focus traversal keys for the given focus traversal operation has been explicitly defined for this Component.
  `Rectangle`
  `bounds()`
  Deprecated.
  As of JDK version 1.1, replaced by `getBounds()`.
  `int`
  `checkImage(Image image, int width, int height, ImageObserver observer)`
  Returns the status of the construction of a screen representation of the specified image.
  `int`
  `checkImage(Image image, ImageObserver observer)`
  Returns the status of the construction of a screen representation of the specified image.
  `protected AWTEvent`
  `coalesceEvents(AWTEvent existingEvent, AWTEvent newEvent)`
  Potentially coalesce an event being posted with an existing event.
  `boolean`
  `contains(int x, int y)`
  Checks whether this component "contains" the specified point, where `x` and `y` are defined to be relative to the coordinate system of this component.
  `boolean`
  `contains(Point p)`
  Checks whether this component "contains" the specified point, where the point's x and y coordinates are defined to be relative to the coordinate system of this component.
  `Image`
  `createImage(int width, int height)`
  Creates an off-screen drawable image to be used for double buffering.
  `Image`
  `createImage(ImageProducer producer)`
  Creates an image from the specified image producer.
  `VolatileImage`
  `createVolatileImage(int width, int height)`
  Creates a volatile off-screen drawable image to be used for double buffering.
  `VolatileImage`
  `createVolatileImage(int width, int height, ImageCapabilities caps)`
  Creates a volatile off-screen drawable image, with the given capabilities.
  `void`
  `deliverEvent(Event e)`
  Deprecated.
  As of JDK version 1.1, replaced by `dispatchEvent(AWTEvent e)`.
  `void`
  `disable()`
  Deprecated.
  As of JDK version 1.1, replaced by `setEnabled(boolean)`.
  `protected final void`
  `disableEvents(long eventsToDisable)`
  Disables the events defined by the specified event mask parameter from being delivered to this component.
  `final void`
  `dispatchEvent(AWTEvent e)`
  Dispatches an event to this component or one of its sub components.
  `void`
  `doLayout()`
  Prompts the layout manager to lay out this component.
  `void`
  `enable()`
  Deprecated.
  As of JDK version 1.1, replaced by `setEnabled(boolean)`.
  `void`
  `enable(boolean b)`
  Deprecated.
  As of JDK version 1.1, replaced by `setEnabled(boolean)`.
  `protected final void`
  `enableEvents(long eventsToEnable)`
  Enables the events defined by the specified event mask parameter to be delivered to this component.
  `void`
  `enableInputMethods(boolean enable)`
  Enables or disables input method support for this component.
  `protected void`
  `firePropertyChange(String propertyName, boolean oldValue, boolean newValue)`
  Support for reporting bound property changes for boolean properties.
  `void`
  `firePropertyChange(String propertyName, byte oldValue, byte newValue)`
  Reports a bound property change.
  `void`
  `firePropertyChange(String propertyName, char oldValue, char newValue)`
  Reports a bound property change.
  `void`
  `firePropertyChange(String propertyName, double oldValue, double newValue)`
  Reports a bound property change.
  `void`
  `firePropertyChange(String propertyName, float oldValue, float newValue)`
  Reports a bound property change.
  `protected void`
  `firePropertyChange(String propertyName, int oldValue, int newValue)`
  Support for reporting bound property changes for integer properties.
  `void`
  `firePropertyChange(String propertyName, long oldValue, long newValue)`
  Reports a bound property change.
  `void`
  `firePropertyChange(String propertyName, short oldValue, short newValue)`
  Reports a bound property change.
  `protected void`
  `firePropertyChange(String propertyName, Object oldValue, Object newValue)`
  Support for reporting bound property changes for Object properties.
  `float`
  `getAlignmentX()`
  Returns the alignment along the x axis.
  `float`
  `getAlignmentY()`
  Returns the alignment along the y axis.
  `Color`
  `getBackground()`
  Gets the background color of this component.
  `int`
  `getBaseline(int width, int height)`
  Returns the baseline.
  `Component.BaselineResizeBehavior`
  `getBaselineResizeBehavior()`
  Returns an enum indicating how the baseline of the component changes as the size changes.
  `Rectangle`
  `getBounds()`
  Gets the bounds of this component in the form of a `Rectangle` object.
  `Rectangle`
  `getBounds(Rectangle rv)`
  Stores the bounds of this component into "return value" rv and return rv.
  `ColorModel`
  `getColorModel()`
  Gets the instance of `ColorModel` used to display the component on the output device.
  `Component`
  `getComponentAt(int x, int y)`
  Determines if this component or one of its immediate subcomponents contains the (x, y) location, and if so, returns the containing component.
  `Component`
  `getComponentAt(Point p)`
  Returns the component or subcomponent that contains the specified point.
  `ComponentListener[]`
  `getComponentListeners()`
  Returns an array of all the component listeners registered on this component.
  `ComponentOrientation`
  `getComponentOrientation()`
  Retrieves the language-sensitive orientation that is to be used to order the elements or text within this component.
  `Cursor`
  `getCursor()`
  Gets the cursor set in the component.
  `DropTarget`
  `getDropTarget()`
  Gets the `DropTarget` associated with this `Component`.
  `Container`
  `getFocusCycleRootAncestor()`
  Returns the Container which is the focus cycle root of this Component's focus traversal cycle.
  `FocusListener[]`
  `getFocusListeners()`
  Returns an array of all the focus listeners registered on this component.
  `Set<AWTKeyStroke>`
  `getFocusTraversalKeys(int id)`
  Returns the Set of focus traversal keys for a given traversal operation for this Component.
  `boolean`
  `getFocusTraversalKeysEnabled()`
  Returns whether focus traversal keys are enabled for this Component.
  `Font`
  `getFont()`
  Gets the font of this component.
  `FontMetrics`
  `getFontMetrics(Font font)`
  Gets the font metrics for the specified font.
  `Color`
  `getForeground()`
  Gets the foreground color of this component.
  `Graphics`
  `getGraphics()`
  Creates a graphics context for this component.
  `GraphicsConfiguration`
  `getGraphicsConfiguration()`
  Gets the `GraphicsConfiguration` associated with this `Component`.
  `int`
  `getHeight()`
  Returns the current height of this component.
  `HierarchyBoundsListener[]`
  `getHierarchyBoundsListeners()`
  Returns an array of all the hierarchy bounds listeners registered on this component.
  `HierarchyListener[]`
  `getHierarchyListeners()`
  Returns an array of all the hierarchy listeners registered on this component.
  `boolean`
  `getIgnoreRepaint()`
  Returns whether or not paint messages received from the operating system should be ignored.
  `InputContext`
  `getInputContext()`
  Gets the input context used by this component for handling the communication with input methods when text is entered in this component.
  `InputMethodListener[]`
  `getInputMethodListeners()`
  Returns an array of all the input method listeners registered on this component.
  `InputMethodRequests`
  `getInputMethodRequests()`
  Gets the input method request handler which supports requests from input methods for this component.
  `KeyListener[]`
  `getKeyListeners()`
  Returns an array of all the key listeners registered on this component.
  `Locale`
  `getLocale()`
  Gets the locale of this component.
  `Point`
  `getLocation()`
  Gets the location of this component in the form of a point specifying the component's top-left corner.
  `Point`
  `getLocation(Point rv)`
  Stores the x,y origin of this component into "return value" rv and return rv.
  `Point`
  `getLocationOnScreen()`
  Gets the location of this component in the form of a point specifying the component's top-left corner in the screen's coordinate space.
  `Dimension`
  `getMaximumSize()`
  Gets the maximum size of this component.
  `Dimension`
  `getMinimumSize()`
  Gets the minimum size of this component.
  `MouseListener[]`
  `getMouseListeners()`
  Returns an array of all the mouse listeners registered on this component.
  `MouseMotionListener[]`
  `getMouseMotionListeners()`
  Returns an array of all the mouse motion listeners registered on this component.
  `Point`
  `getMousePosition()`
  Returns the position of the mouse pointer in this `Component`'s coordinate space if the `Component` is directly under the mouse pointer, otherwise returns `null`.
  `MouseWheelListener[]`
  `getMouseWheelListeners()`
  Returns an array of all the mouse wheel listeners registered on this component.
  `String`
  `getName()`
  Gets the name of the component.
  `Container`
  `getParent()`
  Gets the parent of this component.
  `Dimension`
  `getPreferredSize()`
  Gets the preferred size of this component.
  `PropertyChangeListener[]`
  `getPropertyChangeListeners()`
  Returns an array of all the property change listeners registered on this component.
  `PropertyChangeListener[]`
  `getPropertyChangeListeners(String propertyName)`
  Returns an array of all the listeners which have been associated with the named property.
  `Dimension`
  `getSize()`
  Returns the size of this component in the form of a `Dimension` object.
  `Dimension`
  `getSize(Dimension rv)`
  Stores the width/height of this component into "return value" rv and return rv.
  `Toolkit`
  `getToolkit()`
  Gets the toolkit of this component.
  `final Object`
  `getTreeLock()`
  Gets this component's locking object (the object that owns the thread synchronization monitor) for AWT component-tree and layout operations.
  `int`
  `getWidth()`
  Returns the current width of this component.
  `int`
  `getX()`
  Returns the current x coordinate of the components origin.
  `int`
  `getY()`
  Returns the current y coordinate of the components origin.
  `boolean`
  `gotFocus(Event evt, Object what)`
  Deprecated.
  As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
  `boolean`
  `handleEvent(Event evt)`
  Deprecated.
  As of JDK version 1.1 replaced by processEvent(AWTEvent).
  `boolean`
  `hasFocus()`
  Returns `true` if this `Component` is the focus owner.
  `void`
  `hide()`
  Deprecated.
  As of JDK version 1.1, replaced by `setVisible(boolean)`.
  `boolean`
  `imageUpdate(Image img, int infoflags, int x, int y, int w, int h)`
  Repaints the component when the image has changed.
  `boolean`
  `inside(int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by contains(int, int).
  `void`
  `invalidate()`
  Invalidates this component and its ancestors.
  `boolean`
  `isBackgroundSet()`
  Returns whether the background color has been explicitly set for this Component.
  `boolean`
  `isCursorSet()`
  Returns whether the cursor has been explicitly set for this Component.
  `boolean`
  `isDisplayable()`
  Determines whether this component is displayable.
  `boolean`
  `isDoubleBuffered()`
  Returns true if this component is painted to an offscreen image ("buffer") that's copied to the screen later.
  `boolean`
  `isEnabled()`
  Determines whether this component is enabled.
  `boolean`
  `isFocusable()`
  Returns whether this Component can be focused.
  `boolean`
  `isFocusCycleRoot(Container container)`
  Returns whether the specified Container is the focus cycle root of this Component's focus traversal cycle.
  `boolean`
  `isFocusOwner()`
  Returns `true` if this `Component` is the focus owner.
  `boolean`
  `isFocusTraversable()`
  Deprecated.
  As of 1.4, replaced by `isFocusable()`.
  `boolean`
  `isFontSet()`
  Returns whether the font has been explicitly set for this Component.
  `boolean`
  `isForegroundSet()`
  Returns whether the foreground color has been explicitly set for this Component.
  `boolean`
  `isLightweight()`
  A lightweight component doesn't have a native toolkit peer.
  `boolean`
  `isMaximumSizeSet()`
  Returns true if the maximum size has been set to a non-`null` value otherwise returns false.
  `boolean`
  `isMinimumSizeSet()`
  Returns whether or not `setMinimumSize` has been invoked with a non-null value.
  `boolean`
  `isOpaque()`
  Returns true if this component is completely opaque, returns false by default.
  `boolean`
  `isPreferredSizeSet()`
  Returns true if the preferred size has been set to a non-`null` value otherwise returns false.
  `boolean`
  `isShowing()`
  Determines whether this component is showing on screen.
  `boolean`
  `isValid()`
  Determines whether this component is valid.
  `boolean`
  `isVisible()`
  Determines whether this component should be visible when its parent is visible.
  `boolean`
  `keyDown(Event evt, int key)`
  Deprecated.
  As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
  `boolean`
  `keyUp(Event evt, int key)`
  Deprecated.
  As of JDK version 1.1, replaced by processKeyEvent(KeyEvent).
  `void`
  `layout()`
  Deprecated.
  As of JDK version 1.1, replaced by `doLayout()`.
  `void`
  `list()`
  Prints a listing of this component to the standard system output stream `System.out`.
  `void`
  `list(PrintStream out)`
  Prints a listing of this component to the specified output stream.
  `void`
  `list(PrintStream out, int indent)`
  Prints out a list, starting at the specified indentation, to the specified print stream.
  `void`
  `list(PrintWriter out)`
  Prints a listing to the specified print writer.
  `void`
  `list(PrintWriter out, int indent)`
  Prints out a list, starting at the specified indentation, to the specified print writer.
  `Component`
  `locate(int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by getComponentAt(int, int).
  `Point`
  `location()`
  Deprecated.
  As of JDK version 1.1, replaced by `getLocation()`.
  `boolean`
  `lostFocus(Event evt, Object what)`
  Deprecated.
  As of JDK version 1.1, replaced by processFocusEvent(FocusEvent).
  `Dimension`
  `minimumSize()`
  Deprecated.
  As of JDK version 1.1, replaced by `getMinimumSize()`.
  `boolean`
  `mouseDown(Event evt, int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
  `boolean`
  `mouseDrag(Event evt, int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
  `boolean`
  `mouseEnter(Event evt, int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
  `boolean`
  `mouseExit(Event evt, int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
  `boolean`
  `mouseMove(Event evt, int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by processMouseMotionEvent(MouseEvent).
  `boolean`
  `mouseUp(Event evt, int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by processMouseEvent(MouseEvent).
  `void`
  `move(int x, int y)`
  Deprecated.
  As of JDK version 1.1, replaced by `setLocation(int, int)`.
  `void`
  `nextFocus()`
  Deprecated.
  As of JDK version 1.1, replaced by transferFocus().
  `void`
  `paint(Graphics g)`
  Paints this component.
  `void`
  `paintAll(Graphics g)`
  Paints this component and all of its subcomponents.
  `boolean`
  `postEvent(Event e)`
  Deprecated.
  As of JDK version 1.1, replaced by dispatchEvent(AWTEvent).
  `Dimension`
  `preferredSize()`
  Deprecated.
  As of JDK version 1.1, replaced by `getPreferredSize()`.
  `boolean`
  `prepareImage(Image image, int width, int height, ImageObserver observer)`
  Prepares an image for rendering on this component at the specified width and height.
  `boolean`
  `prepareImage(Image image, ImageObserver observer)`
  Prepares an image for rendering on this component.
  `void`
  `print(Graphics g)`
  Prints this component.
  `void`
  `printAll(Graphics g)`
  Prints this component and all of its subcomponents.
  `protected void`
  `processComponentEvent(ComponentEvent e)`
  Processes component events occurring on this component by dispatching them to any registered `ComponentListener` objects.
  `protected void`
  `processFocusEvent(FocusEvent e)`
  Processes focus events occurring on this component by dispatching them to any registered `FocusListener` objects.
  `protected void`
  `processHierarchyBoundsEvent(HierarchyEvent e)`
  Processes hierarchy bounds events occurring on this component by dispatching them to any registered `HierarchyBoundsListener` objects.
  `protected void`
  `processHierarchyEvent(HierarchyEvent e)`
  Processes hierarchy events occurring on this component by dispatching them to any registered `HierarchyListener` objects.
  `protected void`
  `processInputMethodEvent(InputMethodEvent e)`
  Processes input method events occurring on this component by dispatching them to any registered `InputMethodListener` objects.
  `protected void`
  `processKeyEvent(KeyEvent e)`
  Processes key events occurring on this component by dispatching them to any registered `KeyListener` objects.
  `protected void`
  `processMouseEvent(MouseEvent e)`
  Processes mouse events occurring on this component by dispatching them to any registered `MouseListener` objects.
  `protected void`
  `processMouseMotionEvent(MouseEvent e)`
  Processes mouse motion events occurring on this component by dispatching them to any registered `MouseMotionListener` objects.
  `protected void`
  `processMouseWheelEvent(MouseWheelEvent e)`
  Processes mouse wheel events occurring on this component by dispatching them to any registered `MouseWheelListener` objects.
  `void`
  `remove(MenuComponent popup)`
  Removes the specified popup menu from the component.
  `void`
  `removeComponentListener(ComponentListener l)`
  Removes the specified component listener so that it no longer receives component events from this component.
  `void`
  `removeFocusListener(FocusListener l)`
  Removes the specified focus listener so that it no longer receives focus events from this component.
  `void`
  `removeHierarchyBoundsListener(HierarchyBoundsListener l)`
  Removes the specified hierarchy bounds listener so that it no longer receives hierarchy bounds events from this component.
  `void`
  `removeHierarchyListener(HierarchyListener l)`
  Removes the specified hierarchy listener so that it no longer receives hierarchy changed events from this component.
  `void`
  `removeInputMethodListener(InputMethodListener l)`
  Removes the specified input method listener so that it no longer receives input method events from this component.
  `void`
  `removeKeyListener(KeyListener l)`
  Removes the specified key listener so that it no longer receives key events from this component.
  `void`
  `removeMouseListener(MouseListener l)`
  Removes the specified mouse listener so that it no longer receives mouse events from this component.
  `void`
  `removeMouseMotionListener(MouseMotionListener l)`
  Removes the specified mouse motion listener so that it no longer receives mouse motion events from this component.
  `void`
  `removeMouseWheelListener(MouseWheelListener l)`
  Removes the specified mouse wheel listener so that it no longer receives mouse wheel events from this component.
  `void`
  `removeNotify()`
  Makes this `Component` undisplayable by destroying it native screen resource.
  `void`
  `removePropertyChangeListener(PropertyChangeListener listener)`
  Removes a PropertyChangeListener from the listener list.
  `void`
  `removePropertyChangeListener(String propertyName, PropertyChangeListener listener)`
  Removes a `PropertyChangeListener` from the listener list for a specific property.
  `void`
  `repaint()`
  Repaints this component.
  `void`
  `repaint(int x, int y, int width, int height)`
  Repaints the specified rectangle of this component.
  `void`
  `repaint(long tm)`
  Repaints the component.
  `void`
  `repaint(long tm, int x, int y, int width, int height)`
  Repaints the specified rectangle of this component within `tm` milliseconds.
  `void`
  `requestFocus()`
  Requests that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.
  `protected boolean`
  `requestFocus(boolean temporary)`
  Requests that this `Component` get the input focus, and that this `Component`'s top-level ancestor become the focused `Window`.
  `protected boolean`
  `requestFocus(boolean temporary, FocusEvent.Cause cause)`
  Requests by the reason of `cause` that this `Component` get the input focus, and that this `Component`'s top-level ancestor become the focused `Window`.
  `void`
  `requestFocus(FocusEvent.Cause cause)`
  Requests by the reason of `cause` that this Component get the input focus, and that this Component's top-level ancestor become the focused Window.
  `boolean`
  `requestFocusInWindow()`
  Requests that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.
  `protected boolean`
  `requestFocusInWindow(boolean temporary)`
  Requests that this `Component` get the input focus, if this `Component`'s top-level ancestor is already the focused `Window`.
  `boolean`
  `requestFocusInWindow(FocusEvent.Cause cause)`
  Requests by the reason of `cause` that this Component get the input focus, if this Component's top-level ancestor is already the focused Window.
  `void`
  `reshape(int x, int y, int width, int height)`
  Deprecated.
  As of JDK version 1.1, replaced by `setBounds(int, int, int, int)`.
  `void`
  `resize(int width, int height)`
  Deprecated.
  As of JDK version 1.1, replaced by `setSize(int, int)`.
  `void`
  `resize(Dimension d)`
  Deprecated.
  As of JDK version 1.1, replaced by `setSize(Dimension)`.
  `void`
  `revalidate()`
  Revalidates the component hierarchy up to the nearest validate root.
  `void`
  `setBackground(Color c)`
  Sets the background color of this component.
  `void`
  `setBounds(int x, int y, int width, int height)`
  Moves and resizes this component.
  `void`
  `setBounds(Rectangle r)`
  Moves and resizes this component to conform to the new bounding rectangle `r`.
  `void`
  `setComponentOrientation(ComponentOrientation o)`
  Sets the language-sensitive orientation that is to be used to order the elements or text within this component.
  `void`
  `setCursor(Cursor cursor)`
  Sets the cursor image to the specified cursor.
  `void`
  `setDropTarget(DropTarget dt)`
  Associate a `DropTarget` with this component.
  `void`
  `setEnabled(boolean b)`
  Enables or disables this component, depending on the value of the parameter `b`.
  `void`
  `setFocusable(boolean focusable)`
  Sets the focusable state of this Component to the specified value.
  `void`
  `setFocusTraversalKeys(int id, Set<? extends AWTKeyStroke> keystrokes)`
  Sets the focus traversal keys for a given traversal operation for this Component.
  `void`
  `setFocusTraversalKeysEnabled(boolean focusTraversalKeysEnabled)`
  Sets whether focus traversal keys are enabled for this Component.
  `void`
  `setFont(Font f)`
  Sets the font of this component.
  `void`
  `setForeground(Color c)`
  Sets the foreground color of this component.
  `void`
  `setIgnoreRepaint(boolean ignoreRepaint)`
  Sets whether or not paint messages received from the operating system should be ignored.
  `void`
  `setLocale(Locale l)`
  Sets the locale of this component.
  `void`
  `setLocation(int x, int y)`
  Moves this component to a new location.
  `void`
  `setLocation(Point p)`
  Moves this component to a new location.
  `void`
  `setMaximumSize(Dimension maximumSize)`
  Sets the maximum size of this component to a constant value.
  `void`
  `setMinimumSize(Dimension minimumSize)`
  Sets the minimum size of this component to a constant value.
  `void`
  `setMixingCutoutShape(Shape shape)`
  Sets a 'mixing-cutout' shape for this lightweight component.
  `void`
  `setName(String name)`
  Sets the name of the component to the specified string.
  `void`
  `setPreferredSize(Dimension preferredSize)`
  Sets the preferred size of this component to a constant value.
  `void`
  `setSize(int width, int height)`
  Resizes this component so that it has width `width` and height `height`.
  `void`
  `setSize(Dimension d)`
  Resizes this component so that it has width `d.width` and height `d.height`.
  `void`
  `setVisible(boolean b)`
  Shows or hides this component depending on the value of parameter `b`.
  `void`
  `show()`
  Deprecated.
  As of JDK version 1.1, replaced by `setVisible(boolean)`.
  `void`
  `show(boolean b)`
  Deprecated.
  As of JDK version 1.1, replaced by `setVisible(boolean)`.
  `Dimension`
  `size()`
  Deprecated.
  As of JDK version 1.1, replaced by `getSize()`.
  `String`
  `toString()`
  Returns a string representation of this component and its values.
  `void`
  `transferFocus()`
  Transfers the focus to the next component, as though this Component were the focus owner.
  `void`
  `transferFocusBackward()`
  Transfers the focus to the previous component, as though this Component were the focus owner.
  `void`
  `transferFocusUpCycle()`
  Transfers the focus up one focus traversal cycle.
  `void`
  `update(Graphics g)`
  Updates this component.
  `void`
  `validate()`
  Validates this component.

  ### Methods declared in class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`
  Modifier and Type
  Method
  Description
  `protected Object`
  `clone()`
  Creates and returns a copy of this object.
  `boolean`
  `equals(Object obj)`
  Indicates whether some other object is "equal to" this one.
  `protected void`
  `finalize()`
  Deprecated, for removal: This API element is subject to removal in a future version.
  Finalization is deprecated and subject to removal in a future release.
  `final Class<?>`
  `getClass()`
  Returns the runtime class of this `Object`.
  `int`
  `hashCode()`
  Returns a hash code value for this object.
  `final void`
  `notify()`
  Wakes up a single thread that is waiting on this object's monitor.
  `final void`
  `notifyAll()`
  Wakes up all threads that are waiting on this object's monitor.
  `final void`
  `wait()`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
  `final void`
  `wait(long timeoutMillis)`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
  `final void`
  `wait(long timeoutMillis, int nanos)`
  Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

- ## Constructor Details

  - ### Checkbox

    public Checkbox() throws HeadlessException
    Creates a check box with an empty string for its label. The state of this check box is set to "off," and it is not part of any check box group.
    Throws:
      `HeadlessException` - if GraphicsEnvironment.isHeadless() returns true
    See Also:
      - `GraphicsEnvironment.isHeadless()`

  - ### Checkbox

    public Checkbox(String label) throws HeadlessException
    Creates a check box with the specified label. The state of this check box is set to "off," and it is not part of any check box group.
    Parameters:
      `label` - a string label for this check box, or `null` for no label.
    Throws:
      `HeadlessException` - if `GraphicsEnvironment.isHeadless` returns `true`
    See Also:
      - `GraphicsEnvironment.isHeadless()`

  - ### Checkbox

    public Checkbox(String label, boolean state) throws HeadlessException
    Creates a check box with the specified label and sets the specified state. This check box is not part of any check box group.
    Parameters:
      `label` - a string label for this check box, or `null` for no label
      `state` - the initial state of this check box
    Throws:
      `HeadlessException` - if `GraphicsEnvironment.isHeadless` returns `true`
    See Also:
      - `GraphicsEnvironment.isHeadless()`

  - ### Checkbox

    public Checkbox(String label, boolean state, CheckboxGroup group) throws HeadlessException
    Constructs a Checkbox with the specified label, set to the specified state, and in the specified check box group.
    Parameters:
      `label` - a string label for this check box, or `null` for no label.
      `state` - the initial state of this check box.
      `group` - a check box group for this check box, or `null` for no group.
    Throws:
      `HeadlessException` - if `GraphicsEnvironment.isHeadless` returns `true`
    Since:
      1.1
    See Also:
      - `GraphicsEnvironment.isHeadless()`

  - ### Checkbox

    public Checkbox(String label, CheckboxGroup group, boolean state) throws HeadlessException
    Creates a check box with the specified label, in the specified check box group, and set to the specified state.
    Parameters:
      `label` - a string label for this check box, or `null` for no label.
      `group` - a check box group for this check box, or `null` for no group.
      `state` - the initial state of this check box.
    Throws:
      `HeadlessException` - if `GraphicsEnvironment.isHeadless` returns `true`
    Since:
      1.1
    See Also:
      - `GraphicsEnvironment.isHeadless()`

- ## Method Details

  - ### addNotify

    public void addNotify()
    Creates the peer of the Checkbox. The peer allows you to change the look of the Checkbox without changing its functionality.
    Overrides:
      `addNotify` in class `Component`
    See Also:
      - `Component.getToolkit()`

  - ### getLabel

    public String getLabel()
    Gets the label of this check box.
    Returns:
      the label of this check box, or `null` if this check box has no label.
    See Also:
      - `setLabel(String)`

  - ### setLabel

    public void setLabel(String label)
    Sets this check box's label to be the string argument.
    Parameters:
      `label` - a string to set as the new label, or `null` for no label.
    See Also:
      - `getLabel()`

  - ### getState

    public boolean getState()
    Determines whether this check box is in the "on" or "off" state. The boolean value `true` indicates the "on" state, and `false` indicates the "off" state.
    Returns:
      the state of this check box, as a boolean value
    See Also:
      - `setState(boolean)`

  - ### setState

    public void setState(boolean state)
    Sets the state of this check box to the specified state. The boolean value `true` indicates the "on" state, and `false` indicates the "off" state.

    Note that this method should be primarily used to initialize the state of the checkbox. Programmatically setting the state of the checkbox will not trigger an `ItemEvent`. The only way to trigger an `ItemEvent` is by user interaction.

    Parameters:
      `state` - the boolean state of the check box
    See Also:
      - `getState()`

  - ### getSelectedObjects

    public Object[] getSelectedObjects()
    Returns an array (length 1) containing the checkbox label or null if the checkbox is not selected.
    Specified by:
      `getSelectedObjects` in interface `ItemSelectable`
    Returns:
      the list of selected objects, or `null`
    See Also:
      - `ItemSelectable`

  - ### getCheckboxGroup

    public CheckboxGroup getCheckboxGroup()
    Determines this check box's group.
    Returns:
      this check box's group, or `null` if the check box is not part of a check box group.
    See Also:
      - `setCheckboxGroup(CheckboxGroup)`

  - ### setCheckboxGroup

    public void setCheckboxGroup(CheckboxGroup g)
    Sets this check box's group to the specified check box group. If this check box is already in a different check box group, it is first taken out of that group.

    If the state of this check box is `true` and the new group already has a check box selected, this check box's state is changed to `false`. If the state of this check box is `true` and the new group has no check box selected, this check box becomes the selected checkbox for the new group and its state is `true`.

    Parameters:
      `g` - the new check box group, or `null` to remove this check box from any check box group
    See Also:
      - `getCheckboxGroup()`

  - ### addItemListener

    public void addItemListener(ItemListener l)
    Adds the specified item listener to receive item events from this check box. Item events are sent to listeners in response to user input, but not in response to calls to setState(). If l is null, no exception is thrown and no action is performed.

    Refer to AWT Threading Issues for details on AWT's threading model.

    Specified by:
      `addItemListener` in interface `ItemSelectable`
    Parameters:
      `l` - the item listener
    Since:
      1.1
    See Also:
      - `removeItemListener(ItemListener)`
      - `getItemListeners()`
      - `setState(boolean)`
      - `ItemEvent`
      - `ItemListener`

  - ### removeItemListener

    public void removeItemListener(ItemListener l)
    Removes the specified item listener so that the item listener no longer receives item events from this check box. If l is null, no exception is thrown and no action is performed.

    Refer to AWT Threading Issues for details on AWT's threading model.

    Specified by:
      `removeItemListener` in interface `ItemSelectable`
    Parameters:
      `l` - the item listener
    Since:
      1.1
    See Also:
      - `addItemListener(ItemListener)`
      - `getItemListeners()`
      - `ItemEvent`
      - `ItemListener`

  - ### getItemListeners

    public ItemListener[] getItemListeners()
    Returns an array of all the item listeners registered on this checkbox.
    Returns:
      all of this checkbox's `ItemListener`s or an empty array if no item listeners are currently registered
    Since:
      1.4
    See Also:
      - `addItemListener(ItemListener)`
      - `removeItemListener(ItemListener)`
      - `ItemEvent`
      - `ItemListener`

  - ### getListeners

    public <T extends EventListener> T[] getListeners(Class<T> listenerType)
    Returns an array of all the objects currently registered as `FooListener`s upon this `Checkbox`. `FooListener`s are registered using the `addFooListener` method.

    You can specify the `listenerType` argument with a class literal, such as `FooListener.class`. For example, you can query a `Checkbox c` for its item listeners with the following code:

        ItemListener[] ils = (ItemListener[])(c.getListeners(ItemListener.class));

    If no such listeners exist, this method returns an empty array.
    Overrides:
      `getListeners` in class `Component`
    Type Parameters:
      `T` - the type of the listeners
    Parameters:
      `listenerType` - the type of listeners requested; this parameter should specify an interface that descends from `java.util.EventListener`
    Returns:
      an array of all objects registered as `FooListener`s on this checkbox, or an empty array if no such listeners have been added
    Throws:
      `ClassCastException` - if `listenerType` doesn't specify a class or interface that implements `java.util.EventListener`
    Since:
      1.3
    See Also:
      - `getItemListeners()`

  - ### processEvent

    protected void processEvent(AWTEvent e)
    Processes events on this check box. If the event is an instance of `ItemEvent`, this method invokes the `processItemEvent` method. Otherwise, it calls its superclass's `processEvent` method.

    Note that if the event parameter is `null` the behavior is unspecified and may result in an exception.

    Overrides:
      `processEvent` in class `Component`
    Parameters:
      `e` - the event
    Since:
      1.1
    See Also:
      - `ItemEvent`
      - `processItemEvent(ItemEvent)`

  - ### processItemEvent

    protected void processItemEvent(ItemEvent e)
    Processes item events occurring on this check box 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`.

    Note that if the event parameter is `null` the behavior is unspecified and may result in an exception.

    Parameters:
      `e` - the item event
    Since:
      1.1
    See Also:
      - `ItemEvent`
      - `ItemListener`
      - `addItemListener(ItemListener)`
      - `Component.enableEvents(long)`

  - ### paramString

    protected String paramString()
    Returns a string representing the state of this `Checkbox`. 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`.
    Overrides:
      `paramString` in class `Component`
    Returns:
      the parameter string of this check box

  - ### getAccessibleContext

    public AccessibleContext getAccessibleContext()
    Gets the AccessibleContext associated with this Checkbox. For checkboxes, the AccessibleContext takes the form of an AccessibleAWTCheckbox. A new AccessibleAWTCheckbox is created if necessary.
    Specified by:
      `getAccessibleContext` in interface `Accessible`
    Overrides:
      `getAccessibleContext` in class `Component`
    Returns:
      an AccessibleAWTCheckbox that serves as the AccessibleContext of this Checkbox
    Since:
      1.3