This class implements accessibility support for the MenuItem class. It provides an implementation of the Java Accessibility API appropriate to menu item user-interface elements. 

Also see:

isEnabled()
setEnabled(boolean)
serial:

Also see:

getLabel()
setLabel(String)
serial:

Also see:

setActionCommand(String)
getActionCommand()
serial:

serial:

 public MenuItem() throws HeadlessException 
{
                                  
        this("", null);
}

Constructs a new MenuItem with an empty label and no keyboard shortcut.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

Also see:

java.awt.GraphicsEnvironment#isHeadless
exception: HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

since: JDK1.1 -

 public MenuItem(String label) throws HeadlessException 
{
        this(label, null);
}

Constructs a new MenuItem with the specified label and no keyboard shortcut. Note that use of "-" in a label is reserved to indicate a separator between menu items. By default, all menu items except for separators are enabled.

Parameters:

label - the label for this menu item.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

Also see:

java.awt.GraphicsEnvironment#isHeadless
exception: HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

since: JDK1.0 -

 public MenuItem(String label,
    MenuShortcut s) throws HeadlessException 
{
        this.label = label;
        this.shortcut = s;
}

Create a menu item with an associated keyboard shortcut. Note that use of "-" in a label is reserved to indicate a separator between menu items. By default, all menu items except for separators are enabled.

Parameters:

label - the label for this menu item.

s - the instance of MenuShortcut associated with this menu item.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

Also see:

java.awt.GraphicsEnvironment#isHeadless
exception: HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

since: JDK1.1 -

 public synchronized  void addActionListener(ActionListener l) 
{
        if (l == null) {
            return;
        }
        actionListener = AWTEventMulticaster.add(actionListener, l);
        newEventsOnly = true;
}

Adds the specified action listener to receive action events from this menu item. 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.

 public  void addNotify() 
{
        synchronized (getTreeLock()) {
            if (peer == null)
                peer = Toolkit.getDefaultToolkit().createMenuItem(this);
        }
}

Creates the menu item's peer. The peer allows us to modify the appearance of the menu item without changing its functionality.

 String constructComponentName() 
{
        synchronized (MenuItem.class) {
            return base + nameCounter++;
        }
}

Construct a name for this MenuComponent. Called by getName() when the name is null.

 public  void deleteShortcut() 
{
        shortcut = null;
        MenuItemPeer peer = (MenuItemPeer)this.peer;
        if (peer != null) {
            peer.setLabel(label);
        }
}

Delete any MenuShortcut object associated with this menu item.

  void deleteShortcut(MenuShortcut s) 
{
        if (s.equals(shortcut)) {
            shortcut = null;
            MenuItemPeer peer = (MenuItemPeer)this.peer;
            if (peer != null) {
                peer.setLabel(label);
            }
        }
}

 public synchronized  void disable() 
{
        enabled = false;
        MenuItemPeer peer = (MenuItemPeer)this.peer;
        if (peer != null) {
            peer.disable();
        }
}

 protected final  void disableEvents(long eventsToDisable) 
{
        eventMask &= ~eventsToDisable;
}

Disables event delivery to this menu item for events defined by the specified event mask parameter.

  void doMenuEvent(long when,
    int modifiers) 
{
        Toolkit.getEventQueue().postEvent(
            new ActionEvent(this, ActionEvent.ACTION_PERFORMED,
                            getActionCommand(), when, modifiers));
}

 public synchronized  void enable() 
{
        enabled = true;
        MenuItemPeer peer = (MenuItemPeer)this.peer;
        if (peer != null) {
            peer.enable();
        }
}

 public  void enable(boolean b) 
{
        if (b) {
            enable();
        } else {
            disable();
        }
}

 protected final  void enableEvents(long eventsToEnable) 
{
        eventMask |= eventsToEnable;
        newEventsOnly = true;
}

Enables event delivery to this menu item for events to be defined by the specified event mask parameter

Since event types are automatically enabled when a listener for that type is added to the menu item, this method only needs to be invoked by subclasses of MenuItem which desire to have the specified event types delivered to processEvent regardless of whether a listener is registered.

 boolean eventEnabled(AWTEvent e) 
{
        if (e.id == ActionEvent.ACTION_PERFORMED) {
            if ((eventMask & AWTEvent.ACTION_EVENT_MASK) != 0 ||
                actionListener != null) {
                return true;
            }
            return false;
        }
        return super.eventEnabled(e);
}

 public AccessibleContext getAccessibleContext() 
{
        if (accessibleContext == null) {
            accessibleContext = new AccessibleAWTMenuItem();
        }
        return accessibleContext;
}

Gets the AccessibleContext associated with this MenuItem. For menu items, the AccessibleContext takes the form of an AccessibleAWTMenuItem. A new AccessibleAWTMenuItem instance is created if necessary.

 public String getActionCommand() 
{
        return getActionCommandImpl();
}

Gets the command name of the action event that is fired by this menu item.

 final String getActionCommandImpl() 
{
        return (actionCommand == null? label : actionCommand);
}

 public synchronized ActionListener[] getActionListeners() 
{
        return (ActionListener[])(getListeners(ActionListener.class));
}

Returns an array of all the action listeners registered on this menu item.

 public String getLabel() 
{
        return label;
}

Gets the label for this menu item.

 public T[] getListeners(Class listenerType) 
{
        EventListener l = null;
        if  (listenerType == ActionListener.class) {
            l = actionListener;
        }
        return AWTEventMulticaster.getListeners(l, listenerType);
}

Returns an array of all the objects currently registered as FooListeners upon this MenuItem. FooListeners 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 MenuItem m for its action listeners with the following code:

ActionListener[] als = (ActionListener[])(m.getListeners(ActionListener.class));

If no such listeners exist, this method returns an empty array.

 public MenuShortcut getShortcut() 
{
        return shortcut;
}

Get the MenuShortcut object associated with this menu item,

 MenuItem getShortcutMenuItem(MenuShortcut s) 
{
        return (s.equals(shortcut)) ? this : null;
}

 boolean handleShortcut(KeyEvent e) 
{
        MenuShortcut s = new MenuShortcut(e.getKeyCode(),
                             (e.getModifiers() & InputEvent.SHIFT_MASK)  > 0);
        // Fix For 6185151: Menu shortcuts of all menuitems within a menu
        // should be disabled when the menu itself is disabled
        if (s.equals(shortcut) && isItemEnabled()) {
            // MenuShortcut match -- issue an event on keydown.
            if (e.getID() == KeyEvent.KEY_PRESSED) {
                doMenuEvent(e.getWhen(), e.getModifiers());
            } else {
                // silently eat key release.
            }
            return true;
        }
        return false;
}

 public boolean isEnabled() 
{
        return enabled;
}

Checks whether this menu item is enabled.

 public String paramString() 
{
        String str = ",label=" + label;
        if (shortcut != null) {
            str += ",shortcut=" + shortcut;
        }
        return super.paramString() + str;
}

Returns a string representing the state of this MenuItem. 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.

 protected  void processActionEvent(ActionEvent e) 
{
        ActionListener listener = actionListener;
        if (listener != null) {
            listener.actionPerformed(e);
        }
}

Processes action events occurring on this menu item, by dispatching them to any registered ActionListener objects. This method is not called unless action events are enabled for this component. Action events are enabled when one of the following occurs:
• An ActionListener object is registered via addActionListener.
• Action events are enabled via enableEvents.

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

 protected  void processEvent(AWTEvent e) 
{
        if (e instanceof ActionEvent) {
            processActionEvent((ActionEvent)e);
        }
}

Processes events on this menu item. If the event is an instance of ActionEvent, it invokes processActionEvent, another method defined by MenuItem.

Currently, menu items only support action events.

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

 public synchronized  void removeActionListener(ActionListener l) 
{
        if (l == null) {
            return;
        }
        actionListener = AWTEventMulticaster.remove(actionListener, l);
}

Removes the specified action listener so it no longer receives action events from this menu item. 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.

 public  void setActionCommand(String command) 
{
        actionCommand = command;
}

Sets the command name of the action event that is fired by this menu item.

By default, the action command is set to the label of the menu item.

 public synchronized  void setEnabled(boolean b) 
{
        enable(b);
}

Sets whether or not this menu item can be chosen.

 public synchronized  void setLabel(String label) 
{
        this.label = label;
        MenuItemPeer peer = (MenuItemPeer)this.peer;
        if (peer != null) {
            peer.setLabel(label);
        }
}

Sets the label for this menu item to the specified label.

 public  void setShortcut(MenuShortcut s) 
{
        shortcut = s;
        MenuItemPeer peer = (MenuItemPeer)this.peer;
        if (peer != null) {
            peer.setLabel(label);
        }
}

Set the MenuShortcut object associated with this menu item. If a menu shortcut is already associated with this menu item, it is replaced.