javax.swing
Class JMenuItem

java.lang.Object
  |
  +--java.awt.Component
        |
        +--java.awt.Container
              |
              +--javax.swing.JComponent
                    |
                    +--javax.swing.AbstractButton
                          |
                          +--javax.swing.JMenuItem

All Implemented Interfaces:

Accessible, ImageObserver, ItemSelectable, MenuContainer, MenuElement, Serializable, SwingConstants

Direct Known Subclasses:

JCheckBoxMenuItem, JMenu, JRadioButtonMenuItem

public class JMenuItem

extends AbstractButton

implements Accessible, MenuElement

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.

For further documentation and for examples, see How to Use Menus in The Java Tutorial. For the keyboard keys used by this component in the standard Look and Feel (L&F) renditions, see the JMenuItem key assignments.

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. A future release of Swing will provide support for long term persistence.

See Also:

JPopupMenu, JMenu, JCheckBoxMenuItem, JRadioButtonMenuItem, Serialized Form

Inner Class Summary

protected class

JMenuItem.AccessibleJMenuItem This class implements accessibility support for the JMenuItem class.

Inner classes inherited from class javax.swing.AbstractButton

AbstractButton.AccessibleAbstractButton, AbstractButton.ButtonChangeListener

Inner classes inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent

Inner classes inherited from class java.awt.Container

Container.AccessibleAWTContainer

Inner classes inherited from class java.awt.Component

Component.AccessibleAWTComponent

Fields inherited from class javax.swing.AbstractButton

actionListener, BORDER_PAINTED_CHANGED_PROPERTY, changeEvent, changeListener, CONTENT_AREA_FILLED_CHANGED_PROPERTY, DISABLED_ICON_CHANGED_PROPERTY, DISABLED_SELECTED_ICON_CHANGED_PROPERTY, FOCUS_PAINTED_CHANGED_PROPERTY, HORIZONTAL_ALIGNMENT_CHANGED_PROPERTY, HORIZONTAL_TEXT_POSITION_CHANGED_PROPERTY, ICON_CHANGED_PROPERTY, itemListener, MARGIN_CHANGED_PROPERTY, MNEMONIC_CHANGED_PROPERTY, model, MODEL_CHANGED_PROPERTY, PRESSED_ICON_CHANGED_PROPERTY, ROLLOVER_ENABLED_CHANGED_PROPERTY, ROLLOVER_ICON_CHANGED_PROPERTY, ROLLOVER_SELECTED_ICON_CHANGED_PROPERTY, SELECTED_ICON_CHANGED_PROPERTY, TEXT_CHANGED_PROPERTY, VERTICAL_ALIGNMENT_CHANGED_PROPERTY, VERTICAL_TEXT_POSITION_CHANGED_PROPERTY

Fields inherited from class javax.swing.JComponent

accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface javax.swing.SwingConstants

BOTTOM, CENTER, EAST, HORIZONTAL, LEADING, LEFT, NORTH, NORTH_EAST, NORTH_WEST, RIGHT, SOUTH, SOUTH_EAST, SOUTH_WEST, TOP, TRAILING, VERTICAL, WEST

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

JMenuItem()
Creates a menuItem with no set text or icon.

JMenuItem(Action a)
Creates a menu item whose properties are taken from the Action supplied.

JMenuItem(Icon icon)
Creates a menuItem with an icon.

JMenuItem(String text)
Creates a menuItem with text.

JMenuItem(String text, Icon icon)
Creates a menu item with the supplied text and icon.

JMenuItem(String text, int mnemonic)
Creates a menuItem with the specified text and keyboard mnemonic.

Method Summary

void	addMenuDragMouseListener(MenuDragMouseListener l) Adds a MenuDragMouseListener to the menu item
void	addMenuKeyListener(MenuKeyListener l) Adds a MenuKeyListener to the menu item
protected void	configurePropertiesFromAction(Action a) Factory method which sets the ActionEvent source's properties according to values from the Action instance.
protected PropertyChangeListener	createActionPropertyChangeListener(Action a) Factory method which creates the PropertyChangeListener used to update the ActionEvent source as properties change on its Action instance.
protected void	fireMenuDragMouseDragged(MenuDragMouseEvent event)
protected void	fireMenuDragMouseEntered(MenuDragMouseEvent event)
protected void	fireMenuDragMouseExited(MenuDragMouseEvent event)
protected void	fireMenuDragMouseReleased(MenuDragMouseEvent event)
protected void	fireMenuKeyPressed(MenuKeyEvent event)
protected void	fireMenuKeyReleased(MenuKeyEvent event)
protected void	fireMenuKeyTyped(MenuKeyEvent event)
KeyStroke	getAccelerator() Returns the KeyStroke which serves as an accelerator for the menu item.
AccessibleContext	getAccessibleContext() Gets the AccessibleContext associated with this JMenuItem.
Component	getComponent() This method returns the java.awt.Component used to paint this object.
MenuElement[]	getSubElements() This method returns an array containing the sub-menu components for this menu component.
String	getUIClassID() Returns the name of the L&F class that renders this component.
protected void	init(String text, Icon icon) Initialize the menu item with the specified text and icon.
boolean	isArmed() Returns whether the menu item is "armed".
void	menuSelectionChanged(boolean isIncluded) Called by the MenuSelectionManager when the MenuElement is selected or unselected.
protected String	paramString() Returns a string representation of this JMenuItem.
void	processKeyEvent(KeyEvent e, MenuElement[] path, MenuSelectionManager manager) Process a key event forwarded from the MenuSelectionManager.
void	processMenuDragMouseEvent(MenuDragMouseEvent e) Handle mouse drag in a menu.
void	processMenuKeyEvent(MenuKeyEvent e) Handle a keystroke in a menu.
void	processMouseEvent(MouseEvent e, MenuElement[] path, MenuSelectionManager manager) Process a mouse event forwarded from the MenuSelectionManager.
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) Set 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) Enable or disable the menu item.
void	setUI(MenuItemUI ui) Sets the L&F object that renders this component.
void	updateUI() Resets the UI property with a value from the current look and feel.

Methods inherited from class javax.swing.AbstractButton

addActionListener, addChangeListener, addItemListener, checkHorizontalKey, checkVerticalKey, createActionListener, createChangeListener, createItemListener, doClick, doClick, fireActionPerformed, fireItemStateChanged, fireStateChanged, getAction, getActionCommand, getDisabledIcon, getDisabledSelectedIcon, getHorizontalAlignment, getHorizontalTextPosition, getIcon, getLabel, getMargin, getMnemonic, getModel, getPressedIcon, getRolloverIcon, getRolloverSelectedIcon, getSelectedIcon, getSelectedObjects, getText, getUI, getVerticalAlignment, getVerticalTextPosition, imageUpdate, isBorderPainted, isContentAreaFilled, isFocusPainted, isFocusTraversable, isRolloverEnabled, isSelected, paintBorder, removeActionListener, removeChangeListener, removeItemListener, setAction, setActionCommand, setBorderPainted, setContentAreaFilled, setDisabledIcon, setDisabledSelectedIcon, setFocusPainted, setHorizontalAlignment, setHorizontalTextPosition, setIcon, setLabel, setMargin, setMnemonic, setMnemonic, setModel, setPressedIcon, setRolloverEnabled, setRolloverIcon, setRolloverSelectedIcon, setSelected, setSelectedIcon, setText, setUI, setVerticalAlignment, setVerticalTextPosition

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getDebugGraphicsOptions, getGraphics, getHeight, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getVerifyInputWhenFocusTarget, getVisibleRect, getWidth, getX, getY, grabFocus, hasFocus, hide, isDoubleBuffered, isFocusCycleRoot, isLightweightComponent, isManagingFocus, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isOptimizedDrawingEnabled, isPaintingTile, isPreferredSizeSet, isRequestFocusEnabled, isValidateRoot, paint, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processFocusEvent, processKeyBinding, processKeyEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setDebugGraphicsOptions, setDoubleBuffered, setFont, setForeground, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getLayout, insets, invalidate, isAncestorOf, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setLayout, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, getBackground, getBounds, getColorModel, getComponentOrientation, getCursor, getDropTarget, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getInputContext, getInputMethodRequests, getLocale, getLocation, getLocationOnScreen, getName, getParent, getPeer, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, inside, isDisplayable, isEnabled, isLightweight, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

JMenuItem

public JMenuItem()

Creates a menuItem with no set text or icon.

JMenuItem

public JMenuItem(Icon icon)

Creates a menuItem with an icon.

Parameters:

icon - the icon of the MenuItem.

JMenuItem

public JMenuItem(String text)

Creates a menuItem with text.

Parameters:

text - the text of the MenuItem.

JMenuItem

public JMenuItem(Action a)

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

Since:

1.3

JMenuItem

public JMenuItem(String text,
                 Icon icon)

Creates a menu item with the supplied text and icon.

Parameters:

text - the text of the MenuItem.

icon - the icon of the MenuItem.

JMenuItem

public JMenuItem(String text,
                 int mnemonic)

Creates a menuItem with the specified text and keyboard mnemonic.

Parameters:

text - the text of the MenuItem.

mnemonic - the keyboard mnemonic for the MenuItem

Method Detail

init

protected void init(String text,
                    Icon icon)

Initialize the menu item with the specified text and icon.

Overrides:

init in class AbstractButton

Parameters:

text - the text of the MenuItem.

icon - the icon of the MenuItem.

setUI

public void setUI(MenuItemUI ui)

Sets the L&F object that renders this component.

Parameters:

ui - the MenuItemUI L&F object

See Also:

UIDefaults.getUI(javax.swing.JComponent)

updateUI

public void updateUI()

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

Overrides:

updateUI in class AbstractButton

See Also:

JComponent.updateUI()

getUIClassID

public String getUIClassID()

Returns the name of the L&F class that renders this component.

Overrides:

getUIClassID in class JComponent

Returns:

"MenuItemUI"

See Also:

JComponent.getUIClassID(), UIDefaults.getUI(javax.swing.JComponent)

setArmed

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

isArmed

public boolean isArmed()

Returns whether the menu item is "armed".

Returns:

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

See Also:

setArmed(boolean)

setEnabled

public void setEnabled(boolean b)

Enable or disable the menu item.

Overrides:

setEnabled in class AbstractButton

Parameters:

b - true to enable the item

setAccelerator

public void setAccelerator(KeyStroke keyStroke)

Set the key combination which invokes the Menu Item's action listeners without navigating the menu hierarchy. It is the UIs responsibility to do install the correct action.

Parameters:

keyStroke - the KeyStroke which will serve as an accelerator

getAccelerator

public KeyStroke getAccelerator()

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

Returns:

a KeyStroke object identifying the accelerator key

configurePropertiesFromAction

protected void configurePropertiesFromAction(Action a)

Factory method which sets the ActionEvent source's properties according to values from the Action instance. The properties which are set may differ for subclasses. By default, the properties which get set are Text, Icon

Overrides:

configurePropertiesFromAction in class AbstractButton

Parameters:

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

Since:

1.3

See Also:

Action, AbstractButton.setAction(javax.swing.Action)

createActionPropertyChangeListener

protected PropertyChangeListener createActionPropertyChangeListener(Action a)

Factory method which creates the PropertyChangeListener used to update the ActionEvent source as properties change on its Action instance. Subclasses may override this in order to provide their own PropertyChangeListener if the set of properties which should be kept up to date differs from the Note that PropertyChangeListeners should avoid holding strong references to the ActionEvent source, as this may hinder garbage collection of the ActionEvent source and all components in its containment hierarchy.

Overrides:

createActionPropertyChangeListener in class AbstractButton

Since:

1.3

See Also:

Action, AbstractButton.setAction(javax.swing.Action)

processMouseEvent

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

Process a mouse event forwarded from the MenuSelectionManager.

Specified by:

processMouseEvent in interface MenuElement

Parameters:

event - A MouseEvent with source being the receiving component.

componentPath - The MenuElement path array to the receiving component.

manager - The MenuSelectionManager for the menu hierarchy. This method should process the MouseEvent and change 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

processKeyEvent

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

Process a key event forwarded from the MenuSelectionManager.

Specified by:

processKeyEvent in interface MenuElement

Parameters:

event - A KeyEvent with source being the receiving component.

componentPath - The MenuElement path array to the receiving component.

manager - The MenuSelectionManager for the menu hierarchy. This method should process the KeyEvent and change 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

processMenuDragMouseEvent

public void processMenuDragMouseEvent(MenuDragMouseEvent e)

Handle mouse drag in a menu.

Parameters:

e - a MenuDragMouseEvent object

processMenuKeyEvent

public void processMenuKeyEvent(MenuKeyEvent e)

Handle a keystroke in a menu.

Parameters:

e - a MenuKeyEvent object

fireMenuDragMouseEntered

protected void fireMenuDragMouseEntered(MenuDragMouseEvent event)

fireMenuDragMouseExited

protected void fireMenuDragMouseExited(MenuDragMouseEvent event)

fireMenuDragMouseDragged

protected void fireMenuDragMouseDragged(MenuDragMouseEvent event)

fireMenuDragMouseReleased

protected void fireMenuDragMouseReleased(MenuDragMouseEvent event)

fireMenuKeyPressed

protected void fireMenuKeyPressed(MenuKeyEvent event)

fireMenuKeyReleased

protected void fireMenuKeyReleased(MenuKeyEvent event)

fireMenuKeyTyped

protected void fireMenuKeyTyped(MenuKeyEvent event)

menuSelectionChanged

public void menuSelectionChanged(boolean isIncluded)

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

Specified by:

menuSelectionChanged in interface MenuElement

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

See Also:

MenuSelectionManager.setSelectedPath(MenuElement[])

getSubElements

public MenuElement[] getSubElements()

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

Specified by:

getSubElements in interface MenuElement

Returns:

an array of MenuElements

getComponent

public Component getComponent()

This method 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.

Specified by:

getComponent in interface MenuElement

Returns:

the Component that paints this menu item

addMenuDragMouseListener

public void addMenuDragMouseListener(MenuDragMouseListener l)

Adds a MenuDragMouseListener to the menu item

removeMenuDragMouseListener

public void removeMenuDragMouseListener(MenuDragMouseListener l)

Removes a MenuDragMouseListener from the menu item

addMenuKeyListener

public void addMenuKeyListener(MenuKeyListener l)

Adds a MenuKeyListener to the menu item

removeMenuKeyListener

public void removeMenuKeyListener(MenuKeyListener l)

Removes a MenuKeyListener from the menu item

paramString

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.

Overrides:

paramString in class AbstractButton

Returns:

a string representation of this JMenuItem.

getAccessibleContext

public AccessibleContext getAccessibleContext()

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

Specified by:

getAccessibleContext in interface Accessible

Overrides:

getAccessibleContext in class JComponent

Returns:

an AccessibleJMenuItem that serves as the AccessibleContext of this JMenuItem