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.
JMenu
, JPopupMenu
, JMenuItem
Modifier and Type | Class and Description |
---|---|
protected class |
JMenuBar.AccessibleJMenuBar This class implements accessibility support for the |
JComponent.AccessibleJComponent
Container.AccessibleAWTContainer
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW
accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH
public JMenuBar()
Creates a new menu bar.
public MenuBarUI getUI()
Returns the menubar's current UI.
setUI(javax.swing.plaf.MenuBarUI)
public void setUI(MenuBarUI ui)
Sets the L&F object that renders this component.
ui
- the new MenuBarUI L&F objectUIDefaults.getUI(javax.swing.JComponent)
public void updateUI()
Resets the UI property with a value from the current look and feel.
updateUI
in class JComponent
JComponent.updateUI()
public String getUIClassID()
Returns the name of the L&F class that renders this component.
getUIClassID
in class JComponent
JComponent.getUIClassID()
, UIDefaults.getUI(javax.swing.JComponent)
public SingleSelectionModel getSelectionModel()
Returns the model object that handles single selections.
SingleSelectionModel
propertySingleSelectionModel
public void setSelectionModel(SingleSelectionModel model)
Sets the model object to handle single selections.
model
- the SingleSelectionModel
to useSingleSelectionModel
public JMenu add(JMenu c)
Appends the specified menu to the end of the menu bar.
c
- the JMenu
component to addpublic JMenu getMenu(int index)
Returns the menu at the specified position in the menu bar.
index
- an integer giving the position in the menu bar, where 0 is the first positionJMenu
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.
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.
menu
- the JMenu that delivers help to the userpublic JMenu getHelpMenu()
Gets the help menu for the menu bar. This method is not yet implemented and will throw an exception.
JMenu
that delivers help to the user@Deprecated public Component getComponentAtIndex(int i)
Deprecated. replaced by getComponent(int i)
Returns the component at the specified index.
i
- an integer specifying the position, where 0 is firstComponent
at the position, or null
for an invalid indexpublic int getComponentIndex(Component c)
Returns the index of the specified component.
c
- the Component
to findpublic void setSelected(Component sel)
Sets the currently selected component, producing a a change to the selection model.
sel
- the Component
to selectpublic boolean isSelected()
Returns true if the menu bar currently has a component selected.
public boolean isBorderPainted()
Returns true if the menu bars border should be painted.
public void setBorderPainted(boolean b)
Sets whether the border should be painted.
b
- if true and border property is not null
, the border is painted.isBorderPainted()
protected void paintBorder(Graphics g)
Paints the menubar's border if BorderPainted
property is true.
paintBorder
in class JComponent
g
- the Graphics
context to use for paintingJComponent.paint(java.awt.Graphics)
, JComponent.setBorder(javax.swing.border.Border)
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.
m
- an Insets object containing the margin valuesInsets
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.
Insets
object containing the margin valuesInsets
public void processMouseEvent(MouseEvent event, MenuElement[] path, MenuSelectionManager manager)
Implemented to be a MenuElement
-- does nothing.
processMouseEvent
in interface MenuElement
getSubElements()
public void processKeyEvent(KeyEvent e, MenuElement[] path, MenuSelectionManager manager)
Implemented to be a MenuElement
-- does nothing.
processKeyEvent
in interface MenuElement
getSubElements()
public void menuSelectionChanged(boolean isIncluded)
Implemented to be a MenuElement
-- does nothing.
menuSelectionChanged
in interface MenuElement
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.
getSubElements
in interface MenuElement
public Component getComponent()
Implemented to be a MenuElement
. Returns this object.
getComponent
in interface MenuElement
Component
(this)getSubElements()
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
.
paramString
in class JComponent
JMenuBar
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.
getAccessibleContext
in interface Accessible
getAccessibleContext
in class Component
protected boolean processKeyBinding(KeyStroke ks, KeyEvent e, int condition, boolean pressed)
Subclassed to check all the child menus.
processKeyBinding
in class JComponent
ks
- the KeyStroke
queriede
- the KeyEvent
condition
- one of the following values: pressed
- true if the key is pressedpublic void addNotify()
Overrides JComponent.addNotify
to register this menu bar with the current keyboard manager.
addNotify
in class JComponent
JComponent.registerKeyboardAction(java.awt.event.ActionListener, java.lang.String, javax.swing.KeyStroke, int)
public void removeNotify()
Overrides JComponent.removeNotify
to unregister this menu bar with the current keyboard manager.
removeNotify
in class JComponent
JComponent.registerKeyboardAction(java.awt.event.ActionListener, java.lang.String, javax.swing.KeyStroke, int)
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