Class JMenuBar

java.lang.Object
java.awt.Component
java.awt.Container
javax.swing.JComponent
javax.swing.JMenuBar
All Implemented Interfaces:
ImageObserver, MenuContainer, Serializable, Accessible, MenuElement
Direct Known Subclasses:
BasicInternalFrameTitlePane.SystemMenuBar
@JavaBean(defaultProperty="UI", description="A container for holding and displaying menus.") public class JMenuBar extends JComponent implements 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.

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 JavaBeans has been added to the java.beans package. Please see XMLEncoder.

Warning: By default, pressing the Tab key does not transfer focus from a JMenuBar which is added to a container together with other Swing components, because the focusTraversalKeysEnabled property of JMenuBar is set to false. To resolve this, you should call the JMenuBar.setFocusTraversalKeysEnabled(true) method.

Since:
1.2
See Also:

  • Constructor Details

    • JMenuBar

      public JMenuBar()
      Creates a new menu bar.

  • Method Details

    • getUI

      public MenuBarUI getUI()
      Returns the menubar's current UI.
      Overrides:
      getUI in class JComponent
      Returns:
      a MenuBarUI which is the menubar's current L&F object
      See Also:

    • setUI

      @BeanProperty(hidden=true, visualUpdate=true, description="The UI object that implements the Component's LookAndFeel.") public void setUI(MenuBarUI ui)
      Sets the L&F object that renders this component.
      Parameters:
      ui - the new MenuBarUI L&F object
      See Also:

    • updateUI

      public void updateUI()
      Resets the UI property with a value from the current look and feel.
      Overrides:
      updateUI in class JComponent
      See Also:

    • getUIClassID

      @BeanProperty(bound=false) 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:

    • getSelectionModel

      public SingleSelectionModel getSelectionModel()
      Returns the model object that handles single selections.
      Returns:
      the SingleSelectionModel property
      See Also:

    • setSelectionModel

      @BeanProperty(description="The selection model, recording which child is selected.") public void setSelectionModel(SingleSelectionModel model)
      Sets the model object to handle single selections.
      Parameters:
      model - the SingleSelectionModel to use
      See Also:

    • 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

      @BeanProperty(bound=false) 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

      @Deprecated 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

      @BeanProperty(bound=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

    • 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

      @BeanProperty(visualUpdate=true, description="Whether the border should be painted.") 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:

    • 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:

    • setMargin

      @BeanProperty(visualUpdate=true, description="The space between the menubar's border and its contents") 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:

    • 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:

    • processMouseEvent

      public void processMouseEvent(MouseEvent event, MenuElement[] path, MenuSelectionManager manager)
      Implemented to be a MenuElement -- does nothing.
      Specified by:
      processMouseEvent in interface MenuElement
      Parameters:
      event - a MouseEvent to be processed
      path - the path of the receiving element in the menu hierarchy
      manager - the MenuSelectionManager for the menu hierarchy
      See Also:

    • processKeyEvent

      public void processKeyEvent(KeyEvent e, MenuElement[] path, MenuSelectionManager manager)
      Implemented to be a MenuElement -- does nothing.
      Specified by:
      processKeyEvent in interface MenuElement
      Parameters:
      e - a KeyEvent to be processed
      path - the path of the receiving element in the menu hierarchy
      manager - the MenuSelectionManager for the menu hierarchy
      See Also:

    • getSubElements

      @BeanProperty(bound=false) 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:

    • 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

      @BeanProperty(bound=false) 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.
      Specified by:
      getAccessibleContext in interface Accessible
      Overrides:
      getAccessibleContext in class Component
      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
      Since:
      1.3

    • addNotify

      public void addNotify()
      Overrides JComponent.addNotify to register this menu bar with the current keyboard manager.
      Overrides:
      addNotify in class JComponent
      See Also:

    • removeNotify

      public void removeNotify()
      Overrides JComponent.removeNotify to unregister this menu bar with the current keyboard manager.
      Overrides:
      removeNotify in class JComponent
      See Also: