javax.swing
Class JMenu

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

public class JMenu

extends JMenuItem

implements Accessible, MenuElement

An implementation of a menu -- a popup window containing JMenuItems that is displayed when the user selects an item on the JMenuBar. In addition to JMenuItems, a JMenu can also contain JSeparators.

In essence, a menu is a button with an associated JPopupMenu. When the "button" is pressed, the JPopupMenu appears. If the "button" is on the JMenuBar, the menu is a top-level window. If the "button" is another menu item, then the JPopupMenu is "pull-right" menu.

For the keyboard keys used by this component in the standard Look and Feel (L&F) renditions, see the JMenu 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:

JMenuItem, JSeparator, JMenuBar, JPopupMenu, Serialized Form

Inner Class Summary

protected class	JMenu.AccessibleJMenu The class used to obtain the accessible role for this object.
protected class	JMenu.WinListener A listener class that watches for a popup window closing.

Inner classes inherited from class javax.swing.JMenuItem

JMenuItem.AccessibleJMenuItem

Inner classes inherited from class javax.swing.AbstractButton

AbstractButton.AccessibleAbstractButton, AbstractButton.ButtonChangeListener

Inner classes inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent

Field Summary

protected JMenu.WinListener

popupListener The window-closing listener for the popup.

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

Constructor Summary

JMenu()
Creates a new JMenu with no text.

JMenu(String s)
Creates a new JMenu with the supplied string as its text

JMenu(String s, boolean b)
Creates a new JMenu with the supplied string as its text and specified as a tear-off menu or not.

Method Summary

JMenuItem	add(Action a) Creates a new menuitem attached to the specified Action object and appends it to the end of this menu.
Component	add(Component c) Appends a component to the end of this menu.
JMenuItem	add(JMenuItem menuItem) Appends a menuitem to the end of this menu.
JMenuItem	add(String s) Creates a new menuitem with the specified text and appends it to the end of this menu.
void	addMenuListener(MenuListener l) Add a listener for menu events
void	addSeparator() Append a new separator to the end of the menu.
protected PropertyChangeListener	createActionChangeListener(JMenuItem b)
protected JMenu.WinListener	createWinListener(JPopupMenu p) Create a window-closing listener for the popup.
void	doClick(int pressTime) Programatically perform a "click".
protected void	fireMenuCanceled() Notify all listeners that have registered interest for notification on this event type.
protected void	fireMenuDeselected() Notify all listeners that have registered interest for notification on this event type.
protected void	fireMenuSelected() Notify all listeners that have registered interest for notification on this event type.
AccessibleContext	getAccessibleContext() Get the AccessibleContext associated with this JComponent
Component	getComponent() This method returns the java.awt.Component used to paint this MenuElement.
int	getDelay() Returns the suggested delay before the menu's PopupMenu is popped up or down.
JMenuItem	getItem(int pos) Returns the JMenuItem at the specified position.
int	getItemCount() Returns the number of items on the menu, including separators.
Component	getMenuComponent(int n) Returns the component at position n
int	getMenuComponentCount() Returns the number of components on the menu.
Component[]	getMenuComponents() Returns an array of the menu's subcomponents
JPopupMenu	getPopupMenu() Returns the popupmenu associated with this menu
MenuElement[]	getSubElements() 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.
JMenuItem	insert(Action a, int pos) Insert a new menuitem attached to the specified Action object at a given position.
JMenuItem	insert(JMenuItem mi, int pos) Insert the specified JMenuitem at a given position.
void	insert(String s, int pos) Insert a new menuitem with the specified text at a given position.
void	insertSeparator(int index) Inserts a separator at the specified position.
boolean	isMenuComponent(Component c) Returns true if the specified component exists in the submenu hierarchy.
boolean	isPopupMenuVisible() Returns true if the menu's popup window is visible.
boolean	isSelected() Returns true if the menu is currently selected (popped up).
boolean	isTearOff() Returns true if the menu can be torn off.
boolean	isTopLevelMenu() Returns true if the menu is a 'top-level menu', that is, if it is the direct child of a menubar.
void	menuSelectionChanged(boolean isIncluded) Messaged when the menubar selection changes to activate or deactivate this menu.
protected String	paramString() Returns a string representation of this JMenu.
protected void	processKeyEvent(KeyEvent e)
void	remove(Component c) Removes the Component from this menu.
void	remove(int pos) Removes the menu item at the specified index from this menu.
void	remove(JMenuItem item) Removes the specified menu item from this menu.
void	removeAll() Remove all menu items from this menu.
void	removeMenuListener(MenuListener l) Remove a listener for menu events
void	setAccelerator(KeyStroke keyStroke) setAccelerator() is not defined for JMenu.
void	setDelay(int d) Sets the suggested delay before the menu's PopupMenu is popped up or down.
void	setMenuLocation(int x, int y) Set the location of the popup component
void	setModel(ButtonModel newModel) Set the data model for the "menu button" -- the label that the user clicks to open or close the menu.
void	setPopupMenuVisible(boolean b) Set the visibility of the Menu's popup portion.
void	setSelected(boolean b) Sets the selection status of the menu.
void	updateUI() Notification from the UIFactory that the L&F has changed.

Methods inherited from class javax.swing.JMenuItem

addMenuDragMouseListener, addMenuKeyListener, fireMenuDragMouseDragged, fireMenuDragMouseEntered, fireMenuDragMouseExited, fireMenuDragMouseReleased, fireMenuKeyPressed, fireMenuKeyReleased, fireMenuKeyTyped, getAccelerator, init, isArmed, processKeyEvent, processMenuDragMouseEvent, processMenuKeyEvent, processMouseEvent, removeMenuDragMouseListener, removeMenuKeyListener, setArmed, setEnabled, setUI

Methods inherited from class javax.swing.AbstractButton

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

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addPropertyChangeListener, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getAlignmentX, getAlignmentY, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getDebugGraphicsOptions, getGraphics, getHeight, getInsets, getInsets, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getVisibleRect, getWidth, getX, getY, grabFocus, hasFocus, isDoubleBuffered, isFocusCycleRoot, isFocusTraversable, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paint, paintChildren, paintComponent, paintImmediately, paintImmediately, processComponentKeyEvent, processFocusEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setDebugGraphicsOptions, setDoubleBuffered, setFont, setForeground, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setUI, setVisible, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

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, print, printComponents, processContainerEvent, processEvent, removeContainerListener, setLayout, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addPropertyChangeListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, getBackground, getBounds, getColorModel, getComponentOrientation, getCursor, getDropTarget, getFont, getFontMetrics, getForeground, getInputContext, getInputMethodRequests, getLocale, getLocation, getLocationOnScreen, getName, getParent, getPeer, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hide, imageUpdate, 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, printAll, processComponentEvent, processInputMethodEvent, processMouseEvent, remove, removeComponentListener, removeFocusListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removePropertyChangeListener, 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

Field Detail

popupListener

protected JMenu.WinListener popupListener

The window-closing listener for the popup.

See Also:

JMenu.WinListener

Constructor Detail

JMenu

public JMenu()

Creates a new JMenu with no text.

JMenu

public JMenu(String s)

Creates a new JMenu with the supplied string as its text

Parameters:

s - The text for the menu label

JMenu

public JMenu(String s,
             boolean b)

Creates a new JMenu with the supplied string as its text and specified as a tear-off menu or not.

Parameters:

s - The text for the menu label

b - can the menu be torn off (not yet implemented)

Method Detail

updateUI

public void updateUI()

Notification from the UIFactory that the L&F has changed. Called to replace the UI with the latest version from the UIFactory.

Overrides:

updateUI in class JMenuItem

See Also:

JComponent.updateUI()

getUIClassID

public String getUIClassID()

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

Returns:

"MenuUI"

Overrides:

getUIClassID in class JMenuItem

See Also:

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

setModel

public void setModel(ButtonModel newModel)

Set the data model for the "menu button" -- the label that the user clicks to open or close the menu.

Parameters:

m - the ButtonModel

Overrides:

setModel in class AbstractButton

See Also:

AbstractButton.getModel()

isSelected

public boolean isSelected()

Returns true if the menu is currently selected (popped up).

Returns:

true if the menu is open, else false

Overrides:

isSelected in class AbstractButton

setSelected

public void setSelected(boolean b)

Sets the selection status of the menu.

Parameters:

b - a boolean value -- true to select the menu and open it, false to unselect the menu and close it

Overrides:

setSelected in class AbstractButton

isPopupMenuVisible

public boolean isPopupMenuVisible()

Returns true if the menu's popup window is visible.

Returns:

true if the menu is visible, else false

setPopupMenuVisible

public void setPopupMenuVisible(boolean b)

Set the visibility of the Menu's popup portion. The popup may only be made visible if the menu is itself showing on the screen.

Parameters:

b - a boolean value -- true to make the menu visible, false to hide it

getDelay

public int getDelay()

Returns the suggested delay before the menu's PopupMenu is popped up or down.

Returns:

an int -- the number of milliseconds to delay

setDelay

public void setDelay(int d)

Sets the suggested delay before the menu's PopupMenu is popped up or down.

Parameters:

d - the number of milliseconds to delay

Throws:

IllegalArgumentException - if the value of d is less than 0.

setMenuLocation

public void setMenuLocation(int x,
                            int y)

Set the location of the popup component

Parameters:

x - the x coordinate of the popup's new position

y - the y coordinate of the popup's new position

add

public JMenuItem add(JMenuItem menuItem)

Appends a menuitem to the end of this menu. Returns the menuitem added.

Parameters:

menuItem - the JMenuitem to be added

Returns:

the JMenuItem added

add

public Component add(Component c)

Appends a component to the end of this menu. Returns the component added.

Parameters:

c - the Component to add

Returns:

the Component added

Overrides:

add in class Container

add

public JMenuItem add(String s)

Creates a new menuitem with the specified text and appends it to the end of this menu.

Parameters:

s - the string for the menuitem to be added

add

public JMenuItem add(Action a)

Creates a new menuitem attached to the specified Action object and appends it to the end of this menu.

Parameters:

a - the Action for the menuitem to be added

See Also:

Action

createActionChangeListener

protected PropertyChangeListener createActionChangeListener(JMenuItem b)

addSeparator

public void addSeparator()

Append a new separator to the end of the menu.

insert

public void insert(String s,
                   int pos)

Insert a new menuitem with the specified text at a given position.

Parameters:

s - the text for the menuitem to add

pos - an int giving the position at which to add the new menuitem

insert

public JMenuItem insert(JMenuItem mi,
                        int pos)

Insert the specified JMenuitem at a given position.

Parameters:

mi - the JMenuitem to add

pos - an int giving the position at which to add the new JMenuitem

insert

public JMenuItem insert(Action a,
                        int pos)

Insert a new menuitem attached to the specified Action object at a given position.

Parameters:

a - the Action object for the menuitem to add

pos - an int giving the position at which to add the new menuitem

insertSeparator

public void insertSeparator(int index)

Inserts a separator at the specified position.

Parameters:

index - an int giving the position at which to insert the menu separator

Throws:

IllegalArgumentException - if the value of index is less than 0.

getItem

public JMenuItem getItem(int pos)

Returns the JMenuItem at the specified position. If the specified position contains a separator, this JMenu is returned.

Parameters:

pos - an int giving the position

Throws:

IllegalArgumentException - if the value of index is less than 0.

getItemCount

public int getItemCount()

Returns the number of items on the menu, including separators. This method is included for AWT compatibility.

Returns:

an int equal to the number of items on the menu

See Also:

getMenuComponentCount()

isTearOff

public boolean isTearOff()

Returns true if the menu can be torn off.

Returns:

true if the menu can be torn off, else false

remove

public void remove(JMenuItem item)

Removes the specified menu item from this menu.

Parameters:

item - the JMenuItem to be removed from the menu

remove

public void remove(int pos)

Removes the menu item at the specified index from this menu.

Parameters:

index - the position of the item to be removed.

Throws:

IllegalArgumentException - if the value of index is less than 0.

Overrides:

remove in class Container

remove

public void remove(Component c)

Removes the Component from this menu.

Parameters:

c - the component to be removed

Overrides:

remove in class Container

removeAll

public void removeAll()

Remove all menu items from this menu.

Overrides:

removeAll in class Container

getMenuComponentCount

public int getMenuComponentCount()

Returns the number of components on the menu.

Returns:

an int -- the number of components on the menu

getMenuComponent

public Component getMenuComponent(int n)

Returns the component at position n

Parameters:

n - the position of the component to be returned

getMenuComponents

public Component[] getMenuComponents()

Returns an array of the menu's subcomponents

Returns:

an array of Components

isTopLevelMenu

public boolean isTopLevelMenu()

Returns true if the menu is a 'top-level menu', that is, if it is the direct child of a menubar.

Returns:

true if the menu is activated from the menu bar, false if the menu is activated from a menu item on another menu

isMenuComponent

public boolean isMenuComponent(Component c)

Returns true if the specified component exists in the submenu hierarchy.

Parameters:

c - the Component to be tested

Returns:

true if the component exists

getPopupMenu

public JPopupMenu getPopupMenu()

Returns the popupmenu associated with this menu

addMenuListener

public void addMenuListener(MenuListener l)

Add a listener for menu events

Parameters:

l - the listener to be added

removeMenuListener

public void removeMenuListener(MenuListener l)

Remove a listener for menu events

Parameters:

l - the listener to be removed

fireMenuSelected

protected void fireMenuSelected()

Notify all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

See Also:

EventListenerList

fireMenuDeselected

protected void fireMenuDeselected()

Notify all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

See Also:

EventListenerList

fireMenuCanceled

protected void fireMenuCanceled()

Notify all listeners that have registered interest for notification on this event type. The event instance is lazily created using the parameters passed into the fire method.

See Also:

EventListenerList

createWinListener

protected JMenu.WinListener createWinListener(JPopupMenu p)

Create a window-closing listener for the popup.

Parameters:

p - the JPopupMenu

See Also:

JMenu.WinListener

menuSelectionChanged

public void menuSelectionChanged(boolean isIncluded)

Messaged when the menubar selection changes to activate or deactivate this menu. Overrides JMenuItem.menuSelectionChanged.

Specified by:

menuSelectionChanged in interface MenuElement

Parameters:

isIncluded - true if this menu is active, false if it is not

Overrides:

menuSelectionChanged in class JMenuItem

getSubElements

public MenuElement[] getSubElements()

Returns an array containing the sub-menu components for this menu component

Specified by:

getSubElements in interface MenuElement

Returns:

an array of MenuElement objects

Overrides:

getSubElements in class JMenuItem

getComponent

public Component getComponent()

This method returns the java.awt.Component used to paint this MenuElement. The returned component is used to convert events and detect if an event is inside a menu component.

Specified by:

getComponent in interface MenuElement

Overrides:

getComponent in class JMenuItem

setAccelerator

public void setAccelerator(KeyStroke keyStroke)

setAccelerator() is not defined for JMenu. Use setMnemonic() instead.

Overrides:

setAccelerator in class JMenuItem

processKeyEvent

protected void processKeyEvent(KeyEvent e)

Overrides:

processKeyEvent in class JComponent

doClick

public void doClick(int pressTime)

Programatically perform a "click". This overrides the method AbstractButton.doClick(int) in order to make the menu pop up.

Overrides:

doClick in class AbstractButton

paramString

protected String paramString()

Returns a string representation of this JMenu. 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.

Overriding paramString() to provide information about the specific new aspects of the JFC components.

Returns:

a string representation of this JMenu.

Overrides:

paramString in class JMenuItem

getAccessibleContext

public AccessibleContext getAccessibleContext()

Get the AccessibleContext associated with this JComponent

Specified by:

getAccessibleContext in interface Accessible

Returns:

the AccessibleContext of this JComponent

Overrides:

getAccessibleContext in class JMenuItem