public class

JMenuItem

extends AbstractButton
implements Accessible MenuElement
java.lang.Object
   ↳ java.awt.Component
     ↳ java.awt.Container
       ↳ javax.swing.JComponent
         ↳ javax.swing.AbstractButton
           ↳ javax.swing.JMenuItem
Known Direct Subclasses

Class Overview

An implementation of an item in a menu. A menu item is essentially a button sitting in a list. When the user selects the "button", the action associated with the menu item is performed. A JMenuItem contained in a JPopupMenu performs exactly that function.

Menu items can be configured, and to some degree controlled, by Actions. Using an Action with a menu item has many benefits beyond directly configuring a menu item. Refer to Swing Components Supporting Action for more details, and you can find more information in How to Use Actions, a section in The Java Tutorial.

For further documentation and for examples, see How to Use Menus in The Java Tutorial.

Warning: Swing is not thread safe. For more information see Swing's Threading Policy.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeansTM has been added to the java.beans package. Please see XMLEncoder.

Summary

Nested Classes
class JMenuItem.AccessibleJMenuItem This class implements accessibility support for the JMenuItem class. 
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Inherited Constants
From class javax.swing.AbstractButton
From class javax.swing.JComponent
From class java.awt.Component
From interface java.awt.image.ImageObserver
From interface javax.swing.SwingConstants
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Inherited Fields
From class javax.swing.AbstractButton
From class javax.swing.JComponent
Public Constructors
JMenuItem()
Creates a JMenuItem with no set text or icon.
JMenuItem(Icon icon)
Creates a JMenuItem with the specified icon.
JMenuItem(String text)
Creates a JMenuItem with the specified text.
JMenuItem(Action a)
Creates a menu item whose properties are taken from the specified Action.
JMenuItem(String text, Icon icon)
Creates a JMenuItem with the specified text and icon.
JMenuItem(String text, int mnemonic)
Creates a JMenuItem with the specified text and keyboard mnemonic.
Public Methods
void addMenuDragMouseListener(MenuDragMouseListener l)
Adds a MenuDragMouseListener to the menu item.
void addMenuKeyListener(MenuKeyListener l)
Adds a MenuKeyListener to the menu item.
KeyStroke getAccelerator()
Returns the KeyStroke which serves as an accelerator for the menu item.
AccessibleContext getAccessibleContext()
Returns the AccessibleContext associated with this JMenuItem.
Component getComponent()
Returns the java.awt.Component used to paint this object.
MenuDragMouseListener[] getMenuDragMouseListeners()
Returns an array of all the MenuDragMouseListeners added to this JMenuItem with addMenuDragMouseListener().
MenuKeyListener[] getMenuKeyListeners()
Returns an array of all the MenuKeyListeners added to this JMenuItem with addMenuKeyListener().
MenuElement[] getSubElements()
This method returns an array containing the sub-menu components for this menu component.
String getUIClassID()
Returns the suffix used to construct the name of the L&F class used to render this component.
boolean isArmed()
Returns whether the menu item is "armed".
void menuSelectionChanged(boolean isIncluded)
Called by the MenuSelectionManager when the MenuElement is selected or unselected.
void processKeyEvent(KeyEvent e, MenuElement[] path, MenuSelectionManager manager)
Processes a key event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using MenuSelectionManager's API.
void processMenuDragMouseEvent(MenuDragMouseEvent e)
Handles mouse drag in a menu.
void processMenuKeyEvent(MenuKeyEvent e)
Handles a keystroke in a menu.
void processMouseEvent(MouseEvent e, MenuElement[] path, MenuSelectionManager manager)
Processes a mouse event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using the MenuSelectionManager's API.
void removeMenuDragMouseListener(MenuDragMouseListener l)
Removes a MenuDragMouseListener from the menu item.
void removeMenuKeyListener(MenuKeyListener l)
Removes a MenuKeyListener from the menu item.
void setAccelerator(KeyStroke keyStroke)
Sets the key combination which invokes the menu item's action listeners without navigating the menu hierarchy.
void setArmed(boolean b)
Identifies the menu item as "armed".
void setEnabled(boolean b)
Enables or disables the menu item.
void setModel(ButtonModel newModel)
Sets the model that this button represents.
void setUI(MenuItemUI ui)
Sets the look and feel object that renders this component.
void updateUI()
Resets the UI property with a value from the current look and feel.
Protected Methods
void actionPropertyChanged(Action action, String propertyName)
Updates the button's state in response to property changes in the associated action.
void configurePropertiesFromAction(Action a)
Sets the properties on this button to match those in the specified Action.
void fireMenuDragMouseDragged(MenuDragMouseEvent event)
Notifies all listeners that have registered interest for notification on this event type.
void fireMenuDragMouseEntered(MenuDragMouseEvent event)
Notifies all listeners that have registered interest for notification on this event type.
void fireMenuDragMouseExited(MenuDragMouseEvent event)
Notifies all listeners that have registered interest for notification on this event type.
void fireMenuDragMouseReleased(MenuDragMouseEvent event)
Notifies all listeners that have registered interest for notification on this event type.
void fireMenuKeyPressed(MenuKeyEvent event)
Notifies all listeners that have registered interest for notification on this event type.
void fireMenuKeyReleased(MenuKeyEvent event)
Notifies all listeners that have registered interest for notification on this event type.
void fireMenuKeyTyped(MenuKeyEvent event)
Notifies all listeners that have registered interest for notification on this event type.
void init(String text, Icon icon)
Initializes the menu item with the specified text and icon.
String paramString()
Returns a string representation of this JMenuItem.
[Expand]
Inherited Methods
From class javax.swing.AbstractButton
From class javax.swing.JComponent
From class java.awt.Container
From class java.awt.Component
From class java.lang.Object
From interface java.awt.ItemSelectable
From interface java.awt.MenuContainer
From interface java.awt.image.ImageObserver
From interface javax.accessibility.Accessible
From interface javax.swing.MenuElement

Public Constructors

public JMenuItem ()

Creates a JMenuItem with no set text or icon.

public JMenuItem (Icon icon)

Creates a JMenuItem with the specified icon.

Parameters
icon the icon of the JMenuItem

public JMenuItem (String text)

Creates a JMenuItem with the specified text.

Parameters
text the text of the JMenuItem

public JMenuItem (Action a)

Creates a menu item whose properties are taken from the specified Action.

Parameters
a the action of the JMenuItem

public JMenuItem (String text, Icon icon)

Creates a JMenuItem with the specified text and icon.

Parameters
text the text of the JMenuItem
icon the icon of the JMenuItem

public JMenuItem (String text, int mnemonic)

Creates a JMenuItem with the specified text and keyboard mnemonic.

Parameters
text the text of the JMenuItem
mnemonic the keyboard mnemonic for the JMenuItem

Public Methods

public void addMenuDragMouseListener (MenuDragMouseListener l)

Adds a MenuDragMouseListener to the menu item.

Parameters
l the MenuDragMouseListener to be added

public void addMenuKeyListener (MenuKeyListener l)

Adds a MenuKeyListener to the menu item.

Parameters
l the MenuKeyListener to be added

public KeyStroke getAccelerator ()

Returns the KeyStroke which serves as an accelerator for the menu item.

Returns
  • a KeyStroke object identifying the accelerator key

public AccessibleContext getAccessibleContext ()

Returns the AccessibleContext associated with this JMenuItem. For JMenuItems, the AccessibleContext takes the form of an AccessibleJMenuItem. A new AccessibleJMenuItme instance is created if necessary.

Returns
  • an AccessibleJMenuItem that serves as the AccessibleContext of this JMenuItem

public Component getComponent ()

Returns the java.awt.Component used to paint this object. The returned component will be used to convert events and detect if an event is inside a menu component.

Returns
  • the Component that paints this menu item

public MenuDragMouseListener[] getMenuDragMouseListeners ()

Returns an array of all the MenuDragMouseListeners added to this JMenuItem with addMenuDragMouseListener().

Returns
  • all of the MenuDragMouseListeners added or an empty array if no listeners have been added

public MenuKeyListener[] getMenuKeyListeners ()

Returns an array of all the MenuKeyListeners added to this JMenuItem with addMenuKeyListener().

Returns
  • all of the MenuKeyListeners added or an empty array if no listeners have been added

public MenuElement[] getSubElements ()

This method returns an array containing the sub-menu components for this menu component.

Returns
  • an array of MenuElements

public String getUIClassID ()

Returns the suffix used to construct the name of the L&F class used to render this component.

Returns
  • the string "MenuItemUI"

public boolean isArmed ()

Returns whether the menu item is "armed".

Returns
  • true if the menu item is armed, and it can be selected

public void menuSelectionChanged (boolean isIncluded)

Called by the MenuSelectionManager when the MenuElement is selected or unselected.

Parameters
isIncluded true if this menu item is on the part of the menu path that changed, false if this menu is part of the a menu path that changed, but this particular part of that path is still the same

public void processKeyEvent (KeyEvent e, MenuElement[] path, MenuSelectionManager manager)

Processes a key event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using MenuSelectionManager's API.

Note: you do not have to forward the event to sub-components. This is done automatically by the MenuSelectionManager.

Parameters
e a KeyEvent
path the MenuElement path array
manager the MenuSelectionManager

public void processMenuDragMouseEvent (MenuDragMouseEvent e)

Handles mouse drag in a menu.

Parameters
e a MenuDragMouseEvent object

public void processMenuKeyEvent (MenuKeyEvent e)

Handles a keystroke in a menu.

Parameters
e a MenuKeyEvent object

public void processMouseEvent (MouseEvent e, MenuElement[] path, MenuSelectionManager manager)

Processes a mouse event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using the MenuSelectionManager's API.

Note: you do not have to forward the event to sub-components. This is done automatically by the MenuSelectionManager.

Parameters
e a MouseEvent
path the MenuElement path array
manager the MenuSelectionManager

public void removeMenuDragMouseListener (MenuDragMouseListener l)

Removes a MenuDragMouseListener from the menu item.

Parameters
l the MenuDragMouseListener to be removed

public void removeMenuKeyListener (MenuKeyListener l)

Removes a MenuKeyListener from the menu item.

Parameters
l the MenuKeyListener to be removed

public void setAccelerator (KeyStroke keyStroke)

Sets the key combination which invokes the menu item's action listeners without navigating the menu hierarchy. It is the UI's responsibility to install the correct action. Note that when the keyboard accelerator is typed, it will work whether or not the menu is currently displayed.

Parameters
keyStroke the KeyStroke which will serve as an accelerator

public void setArmed (boolean b)

Identifies the menu item as "armed". If the mouse button is released while it is over this item, the menu's action event will fire. If the mouse button is released elsewhere, the event will not fire and the menu item will be disarmed.

Parameters
b true to arm the menu item so it can be selected

public void setEnabled (boolean b)

Enables or disables the menu item.

Parameters
b true to enable the item

public void setModel (ButtonModel newModel)

Sets the model that this button represents.

Parameters
newModel the new ButtonModel

public void setUI (MenuItemUI ui)

Sets the look and feel object that renders this component.

Parameters
ui the JMenuItemUI L&F object

public void updateUI ()

Resets the UI property with a value from the current look and feel.

See Also

Protected Methods

protected void actionPropertyChanged (Action action, String propertyName)

Updates the button's state in response to property changes in the associated action. This method is invoked from the PropertyChangeListener returned from createActionPropertyChangeListener. Subclasses do not normally need to invoke this. Subclasses that support additional Action properties should override this and configurePropertiesFromAction.

Refer to the table at Swing Components Supporting Action for a list of the properties this method sets.

Parameters
action the Action associated with this button
propertyName the name of the property that changed

protected void configurePropertiesFromAction (Action a)

Sets the properties on this button to match those in the specified Action. Refer to Swing Components Supporting Action for more details as to which properties this sets.

Parameters
a the Action from which to get the properties, or null

protected void fireMenuDragMouseDragged (MenuDragMouseEvent event)

Notifies all listeners that have registered interest for notification on this event type.

Parameters
event a MenuDragMouseEvent

protected void fireMenuDragMouseEntered (MenuDragMouseEvent event)

Notifies all listeners that have registered interest for notification on this event type.

Parameters
event a MenuMouseDragEvent

protected void fireMenuDragMouseExited (MenuDragMouseEvent event)

Notifies all listeners that have registered interest for notification on this event type.

Parameters
event a MenuDragMouseEvent

protected void fireMenuDragMouseReleased (MenuDragMouseEvent event)

Notifies all listeners that have registered interest for notification on this event type.

Parameters
event a MenuDragMouseEvent

protected void fireMenuKeyPressed (MenuKeyEvent event)

Notifies all listeners that have registered interest for notification on this event type.

Parameters
event a MenuKeyEvent

protected void fireMenuKeyReleased (MenuKeyEvent event)

Notifies all listeners that have registered interest for notification on this event type.

Parameters
event a MenuKeyEvent

protected void fireMenuKeyTyped (MenuKeyEvent event)

Notifies all listeners that have registered interest for notification on this event type.

Parameters
event a MenuKeyEvent

protected void init (String text, Icon icon)

Initializes the menu item with the specified text and icon.

Parameters
text the text of the JMenuItem
icon the icon of the JMenuItem

protected String paramString ()

Returns a string representation of this JMenuItem. 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.

Returns
  • a string representation of this JMenuItem