[Chapter 19] CheckboxMenuItem

#

| Chapter 19 java.awt Reference |

# CheckboxMenuItem

## Name

CheckboxMenuItem

##

## Description

The `CheckboxMenuItem` class represents a menu item with a boolean state.

## Class Definition

    public class java.awt.CheckboxMenuItem
        extends java.awt.MenuItem
        implements java.awt.ItemSelectable {

      // Constructors
      public CheckboxMenuItem();
      public CheckboxMenuItem (String label);
      public CheckboxMenuItem (String label, boolean state);

      // Instance Methods
      public void addItemListener (ItemListener l);
      public void addNotify();
      public Object[] getSelectedObjects();
      public boolean getState();
      public String paramString();
      public void removeItemListener (ItemListener l);
      public synchronized void setState (boolean condition);

      // Protected Instance Methods
      protected void processEvent (AWTEvent e);
      protected void processItemEvent (ItemEvent e);
    }

## Constructors

### CheckboxMenuItem

#### public CheckboxMenuItem()

Description

  Constructs a `CheckboxMenuItem` object with no label.

#### public CheckboxMenuItem (String label)

Parameters

  label

    Text that appears on `CheckboxMenuItem`.

Description

  Constructs a `CheckboxMenuItem` object whose value is initially `false`.

#### public CheckboxMenuItem (String label, boolean state)

Parameters

  label

    Text that appears on `CheckboxMenuItem`.

  state

    The initial state of the menu item.

Description

  Constructs a `CheckboxMenuItem` object with the specified `label` and `state`.

## Instance Methods

### addItemListener

#### public void addItemListener (ItemListener l)

Parameters

  l

    The listener to be added.

Implements

  `ItemSelectable.addItemListener(ItemListener l)`

Description

  Adds a listener for the `ItemEvent` objects this `CheckboxMenuItem` fires off.

### addNotify

#### public void addNotify()

Overrides

  `MenuItem.addNotify()`

Description

  Creates `CheckboxMenuItem`'s peer.

### getSelectedObjects

#### public Object[] getSelectedObjects()

Implements

  `ItemSelectable.getSelectedObjects()`

Description

  If the `CheckboxMenuItem` is checked, returns an array with length `1` containing the label of the `CheckboxMenuItem`; otherwise returns `null`.

### getState

#### public boolean getState()

Returns

  The current state of the `CheckboxMenuItem`.

### paramString

#### public String paramString()

Returns

  A string with current settings of `CheckboxMenuItem`.

Overrides

  `MenuItem.paramString()`

Description

  Helper method for `toString()` to generate string of current settings.

### removeItemListener

#### public void removeItemListener (ItemListener l)

Parameters

  l

    The listener to be removed.

Implements

  `ItemSelectable.removeItemListener (ItemListener l)`

Description

  Removes the specified `ItemListener` so it will not receive `ItemEvent` objects from this `CheckboxMenuItem`.

### setState

#### public synchronized void setState (boolean condition)

Parameters

  condition

    New state for the `CheckboxMenuItem`.

Description

  Changes the state of the `CheckboxMenuItem`.

## Protected Instance Methods

### processEvent

#### protected void processEvent(AWTEvent e)

Parameters

  e

    The event to process.

Overrides

  `MenuItem.processEvent(AWTEvent)`

Description

  Low level `AWTEvent`s are passed to this method for processing.

### processItemEvent

#### protected void processItemEvent(ItemEvent e)

Parameters

  e

    The item event to process.

Description

  Item events are passed to this method for processing. Normally, this method is called by `processEvent()`.

## See Also

`ItemEvent`, `ItemSelectable`, `MenuItem`, `String`

CheckboxGroup |  | Choice