Module java.desktop
Package javax.swing

Class 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:
    JMenu, JPopupMenu, JMenuItem, Serialized Form

    • Constructor Detail

      • JMenuBar

        public JMenuBar​()
        Creates a new menu bar.

    • Method Detail

      • getSelectionModel

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

        @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:
        isBorderPainted()

      • 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:
        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
        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:
        getSubElements()

      • 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()

      • menuSelectionChanged

        public void menuSelectionChanged​(boolean isIncluded)
        Implemented to be a MenuElement -- does nothing.
        Specified by:
        menuSelectionChanged in interface MenuElement
        Parameters:
        isIncluded - can be used to indicate if this MenuElement is active (if it is a menu) or is on the part of the menu path that changed (if it is a menu item).
        See Also:
        getSubElements()

      • 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.

      • 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