public class

JMenuBar

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

Class Overview

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.

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 JMenuBar.AccessibleJMenuBar This class implements accessibility support for the JMenuBar class. 
[Expand]
Inherited Constants
From class javax.swing.JComponent
From class java.awt.Component
From interface java.awt.image.ImageObserver
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Inherited Fields
From class javax.swing.JComponent
Public Constructors
JMenuBar()
Creates a new menu bar.
Public Methods
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.
AccessibleContext getAccessibleContext()
Gets the AccessibleContext associated with this JMenuBar.
Component getComponent()
Implemented to be a MenuElement.
Component getComponentAtIndex(int i)
This method is 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.
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.
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.
Protected Methods
void paintBorder(Graphics g)
Paints the menubar's border if BorderPainted property is true.
String paramString()
Returns a string representation of this JMenuBar.
boolean processKeyBinding(KeyStroke ks, KeyEvent e, int condition, boolean pressed)
Subclassed to check all the child menus.
[Expand]
Inherited Methods
From class javax.swing.JComponent
From class java.awt.Container
From class java.awt.Component
From class java.lang.Object
From interface java.awt.MenuContainer
From interface java.awt.image.ImageObserver
From interface javax.accessibility.Accessible
From interface javax.swing.MenuElement

Public Constructors

public JMenuBar ()

Creates a new menu bar.

Public Methods

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

public void addNotify ()

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

public 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.

Returns
  • an AccessibleJMenuBar that serves as the AccessibleContext of this JMenuBar

public Component getComponent ()

Implemented to be a MenuElement. Returns this object.

Returns
  • the current Component (this)
See Also

public Component getComponentAtIndex (int i)

This method is 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

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

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

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

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)

public int getMenuCount ()

Returns the number of items in the menu bar.

Returns
  • the number of items in the menu bar

public SingleSelectionModel getSelectionModel ()

Returns the model object that handles single selections.

Returns
  • the SingleSelectionModel property

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.

Returns
  • an array of menu items in the menu bar.

public MenuBarUI getUI ()

Returns the menubar's current UI.

public String getUIClassID ()

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

Returns
  • the string "MenuBarUI"

public boolean isBorderPainted ()

Returns true if the menu bars border should be painted.

Returns
  • true if the border should be painted, else false

public boolean isSelected ()

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

Returns
  • true if a selection has been made, else false

public void menuSelectionChanged (boolean isIncluded)

Implemented to be a MenuElement -- does nothing.

See Also

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

Implemented to be a MenuElement -- does nothing.

See Also

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

Implemented to be a MenuElement -- does nothing.

See Also

public void removeNotify ()

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

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.

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

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

public void setSelected (Component sel)

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

Parameters
sel the Component to select

public void setSelectionModel (SingleSelectionModel model)

Sets the model object to handle single selections.

Parameters
model the SingleSelectionModel to use

public void setUI (MenuBarUI ui)

Sets the L&F object that renders this component.

Parameters
ui the new MenuBarUI 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 paintBorder (Graphics g)

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

Parameters
g the Graphics context to use for painting

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.

Returns
  • a string representation of this JMenuBar

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

Subclassed to check all the child menus.

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