javax.swing
Class JMenuBar

java.lang.Object
  java.awt.Component
      java.awt.Container
          javax.swing.JComponent
              javax.swing.JMenuBar

All Implemented Interfaces:

javax.accessibility.Accessible, ImageObserver, MenuContainer, MenuElement, Serializable

Direct Known Subclasses:

BasicInternalFrameTitlePane.SystemMenuBar, MetalTitlePane.SystemMenuBar

public class JMenuBar

extends JComponent

implements javax.accessibility.Accessible, MenuElement

An implementation of a menu bar. You add JMenu objects to the menu bar to construct a menu. When the user selects a JMenu object, its associated JPopupMenu is displayed, allowing the user to select one of the JMenuItems on it.

For information and examples of using menu bars see How to Use Menus, a section in The Java Tutorial. For the keyboard keys used by this component in the standard Look and Feel (L&F) renditions, see the JMenuBar 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. As of 1.4, support for long term storage of all JavaBeans^TM has been added to the java.beans package. Please see XMLEncoder.

Author:

Georges Saab, David Karlton, Arnaud Weber

See Also:

JMenu, JPopupMenu, JMenuItem, Serialized Form

Nested Class Summary

protected class

JMenuBar.AccessibleJMenuBar This class implements accessibility support for the JMenuBar class.

Nested classes inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent, JComponent.ActionStandin, JComponent.IntVector, JComponent.KeyboardState

Nested classes inherited from class java.awt.Container

Container.AccessibleAWTContainer

Nested classes inherited from class java.awt.Component

Component.AccessibleAWTComponent, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

private static boolean	DEBUG
private Insets	margin
private boolean	paintBorder
private SingleSelectionModel	selectionModel
private static boolean	TRACE
private static String	uiClassID
private static boolean	VERBOSE

Fields inherited from class javax.swing.JComponent

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

Fields inherited from class java.awt.Container

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

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

Constructor Summary

JMenuBar()
Creates a new menu bar.

Method Summary

JMenu	add(JMenu c) Appends the specified menu to the end of the menu bar.
void	addNotify() Overrides JComponent.addNotify to register this menu bar with the current keyboard manager.
javax.accessibility.AccessibleContext	getAccessibleContext() Gets the AccessibleContext associated with this JMenuBar.
Component	getComponent() Implemented to be a MenuElement.
Component	getComponentAtIndex(int i) Deprecated. replaced by getComponent(int i)
int	getComponentIndex(Component c) Returns the index of the specified component.
JMenu	getHelpMenu() Gets the help menu for the menu bar.
Insets	getMargin() Returns the margin between the menubar's border and its menus.
JMenu	getMenu(int index) Returns the menu at the specified position in the menu bar.
int	getMenuCount() Returns the number of items in the menu bar.
SingleSelectionModel	getSelectionModel() Returns the model object that handles single selections.
MenuElement[]	getSubElements() Implemented to be a MenuElement -- returns the menus in this menu bar.
MenuBarUI	getUI() Returns the menubar's current UI.
String	getUIClassID() Returns the name of the L&F class that renders this component.
boolean	isBorderPainted() Returns true if the menu bars border should be painted.
boolean	isSelected() Returns true if the menu bar currently has a component selected.
void	menuSelectionChanged(boolean isIncluded) Implemented to be a MenuElement -- does nothing.
protected void	paintBorder(Graphics g) Paints the menubar's border if BorderPainted property is true.
protected String	paramString() Returns a string representation of this JMenuBar.
(package private) static boolean	processBindingForKeyStrokeRecursive(MenuElement elem, KeyStroke ks, KeyEvent e, int condition, boolean pressed)
protected boolean	processKeyBinding(KeyStroke ks, KeyEvent e, int condition, boolean pressed) Subclassed to check all the child menus.
void	processKeyEvent(KeyEvent e, MenuElement[] path, MenuSelectionManager manager) Implemented to be a MenuElement -- does nothing.
void	processMouseEvent(MouseEvent event, MenuElement[] path, MenuSelectionManager manager) Implemented to be a MenuElement -- does nothing.
private void	readObject(ObjectInputStream s) See JComponent.readObject() for information about serialization in Swing.
void	removeNotify() Overrides JComponent.removeNotify to unregister this menu bar with the current keyboard manager.
void	setBorderPainted(boolean b) Sets whether the border should be painted.
void	setHelpMenu(JMenu menu) Sets the help menu that appears when the user selects the "help" option in the menu bar.
void	setMargin(Insets m) Sets the margin between the menubar's border and its menus.
void	setSelected(Component sel) Sets the currently selected component, producing a a change to the selection model.
void	setSelectionModel(SingleSelectionModel model) Sets the model object to handle single selections.
void	setUI(MenuBarUI 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.
private void	writeObject(ObjectOutputStream s) Before writing a JComponent to an ObjectOutputStream we temporarily uninstall its UI.

Methods inherited from class javax.swing.JComponent

_paintImmediately, addAncestorListener, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, alwaysOnTop, checkIfChildObscuredBySibling, componentInputMapChanged, computeVisibleRect, computeVisibleRect, compWriteObjectNotify, contains, createToolTip, disable, enable, enableSerialization, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getCreatedDoubleBuffer, getDebugGraphicsOptions, getDefaultLocale, getGraphics, getHeight, getInputMap, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getManagingFocusBackwardTraversalKeys, getManagingFocusForwardTraversalKeys, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getWriteObjCounter, getX, getY, grabFocus, isDoubleBuffered, isLightweightComponent, isManagingFocus, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isOptimizedDrawingEnabled, isPaintingOrigin, isPaintingTile, isPreferredSizeSet, isRequestFocusEnabled, isValidateRoot, paint, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBindings, processKeyBindingsForAllComponents, processKeyEvent, processMouseMotionEvent, putClientProperty, rectangleIsObscured, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setCreatedDoubleBuffer, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFont, setForeground, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPaintingChild, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, setWriteObjCounter, shouldDebugGraphics, superProcessMouseMotionEvent, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setLayout, transferFocusBackward, transferFocusDownCycle, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getParent, getPeer, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

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

Field Detail

uiClassID

private static final String uiClassID

See Also:

getUIClassID(), readObject(java.io.ObjectInputStream), Constant Field Values

selectionModel

private transient SingleSelectionModel selectionModel

paintBorder

private boolean paintBorder

margin

private Insets margin

TRACE

private static final boolean TRACE

See Also:

Constant Field Values

VERBOSE

private static final boolean VERBOSE

See Also:

Constant Field Values

DEBUG

private static final boolean DEBUG

See Also:

Constant Field Values

Constructor Detail

JMenuBar

public JMenuBar()

Creates a new menu bar.

Method Detail

getUI

public MenuBarUI getUI()

Returns the menubar's current UI.

See Also:

setUI(javax.swing.plaf.MenuBarUI)

setUI

public void setUI(MenuBarUI ui)

Sets the L&F object that renders this component.

Parameters:

ui - the new MenuBarUI 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 JComponent

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:

the string "MenuBarUI"

See Also:

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

getSelectionModel

public SingleSelectionModel getSelectionModel()

Returns the model object that handles single selections.

Returns:

the SingleSelectionModel property

See Also:

SingleSelectionModel

setSelectionModel

public void setSelectionModel(SingleSelectionModel model)

Sets the model object to handle single selections.

Parameters:

model - the SingleSelectionModel to use

See Also:

SingleSelectionModel

add

public JMenu add(JMenu c)

Appends the specified menu to the end of the menu bar.

Parameters:

c - the JMenu component to add

Returns:

the menu component

getMenu

public JMenu getMenu(int index)

Returns the menu at the specified position in the menu bar.

Parameters:

index - an integer giving the position in the menu bar, where 0 is the first position

Returns:

the JMenu at that position, or null if if there is no JMenu at that position (ie. if it is a JMenuItem)

getMenuCount

public int getMenuCount()

Returns the number of items in the menu bar.

Returns:

the number of items in the menu bar

setHelpMenu

public void setHelpMenu(JMenu menu)

Sets the help menu that appears when the user selects the "help" option in the menu bar. This method is not yet implemented and will throw an exception.

Parameters:

menu - the JMenu that delivers help to the user

getHelpMenu

public JMenu getHelpMenu()

Gets the help menu for the menu bar. This method is not yet implemented and will throw an exception.

Returns:

the JMenu that delivers help to the user

getComponentAtIndex

public Component getComponentAtIndex(int i)

Deprecated. replaced by getComponent(int i)

Returns the component at the specified index.

Parameters:

i - an integer specifying the position, where 0 is first

Returns:

the Component at the position, or null for an invalid index

getComponentIndex

public int getComponentIndex(Component c)

Returns the index of the specified component.

Parameters:

c - the Component to find

Returns:

an integer giving the component's position, where 0 is first; or -1 if it can't be found

setSelected

public void setSelected(Component sel)

Sets the currently selected component, producing a a change to the selection model.

Parameters:

sel - the Component to select

isSelected

public boolean isSelected()

Returns true if the menu bar currently has a component selected.

Returns:

true if a selection has been made, else false

isBorderPainted

public boolean isBorderPainted()

Returns true if the menu bars border should be painted.

Returns:

true if the border should be painted, else false

setBorderPainted

public void setBorderPainted(boolean b)

Sets whether the border should be painted.

Parameters:

b - if true and border property is not null, the border is painted.

See Also:

isBorderPainted()

paintBorder

protected void paintBorder(Graphics g)

Paints the menubar's border if BorderPainted property is true.

Overrides:

paintBorder in class JComponent

Parameters:

g - the Graphics context to use for painting

See Also:

JComponent.paint(java.awt.Graphics), JComponent.setBorder(javax.swing.border.Border)

setMargin

public void setMargin(Insets m)

Sets the margin between the menubar's border and its menus. Setting to null will cause the menubar to use the default margins.

Parameters:

m - an Insets object containing the margin values

See Also:

Insets

getMargin

public Insets getMargin()

Returns the margin between the menubar's border and its menus. If there is no previous margin, it will create a default margin with zero size.

Returns:

an Insets object containing the margin values

See Also:

Insets

processMouseEvent

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

Implemented to be a MenuElement -- does nothing.

Specified by:

processMouseEvent in interface MenuElement

See Also:

getSubElements()

processKeyEvent

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

Implemented to be a MenuElement -- does nothing.

Specified by:

processKeyEvent in interface MenuElement

See Also:

getSubElements()

menuSelectionChanged

public void menuSelectionChanged(boolean isIncluded)

Implemented to be a MenuElement -- does nothing.

Specified by:

menuSelectionChanged in interface MenuElement

See Also:

getSubElements()

getSubElements

public MenuElement[] getSubElements()

Implemented to be a MenuElement -- returns the menus in this menu bar. This is the reason for implementing the MenuElement interface -- so that the menu bar can be treated the same as other menu elements.

Specified by:

getSubElements in interface MenuElement

Returns:

an array of menu items in the menu bar.

getComponent

public Component getComponent()

Implemented to be a MenuElement. Returns this object.

Specified by:

getComponent in interface MenuElement

Returns:

the current Component (this)

See Also:

getSubElements()

paramString

protected String paramString()

Returns a string representation of this JMenuBar. 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 JComponent

Returns:

a string representation of this JMenuBar

getAccessibleContext

public javax.accessibility.AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this JMenuBar. For JMenuBars, the AccessibleContext takes the form of an AccessibleJMenuBar. A new AccessibleJMenuBar instance is created if necessary.

Specified by:

getAccessibleContext in interface javax.accessibility.Accessible

Overrides:

getAccessibleContext in class JComponent

Returns:

an AccessibleJMenuBar that serves as the AccessibleContext of this JMenuBar

processKeyBinding

protected boolean processKeyBinding(KeyStroke ks,
                                    KeyEvent e,
                                    int condition,
                                    boolean pressed)

Subclassed to check all the child menus.

Overrides:

processKeyBinding in class JComponent

Parameters:

ks - the KeyStroke queried

e - the KeyEvent

condition - one of the following values:

• JComponent.WHEN_FOCUSED
• JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT
• JComponent.WHEN_IN_FOCUSED_WINDOW

pressed - true if the key is pressed

Returns:

true if there was a binding to an action, and the action was enabled

processBindingForKeyStrokeRecursive

static boolean processBindingForKeyStrokeRecursive(MenuElement elem,
                                                   KeyStroke ks,
                                                   KeyEvent e,
                                                   int condition,
                                                   boolean pressed)

addNotify

public void addNotify()

Overrides JComponent.addNotify to register this menu bar with the current keyboard manager.

Overrides:

addNotify in class JComponent

See Also:

JComponent.registerKeyboardAction(java.awt.event.ActionListener, java.lang.String, javax.swing.KeyStroke, int)

removeNotify

public void removeNotify()

Overrides JComponent.removeNotify to unregister this menu bar with the current keyboard manager.

Overrides:

removeNotify in class JComponent

See Also:

JComponent.registerKeyboardAction(java.awt.event.ActionListener, java.lang.String, javax.swing.KeyStroke, int)

writeObject

private void writeObject(ObjectOutputStream s)
                  throws IOException

Description copied from class: JComponent

Before writing a JComponent to an ObjectOutputStream we temporarily uninstall its UI. This is tricky to do because we want to uninstall the UI before any of the JComponent's children (or its LayoutManager etc.) are written, and we don't want to restore the UI until the most derived JComponent subclass has been been stored.

Throws:

IOException

readObject

private void readObject(ObjectInputStream s)
                 throws IOException,
                        ClassNotFoundException

See JComponent.readObject() for information about serialization in Swing.

Throws:

IOException

ClassNotFoundException