Module java.desktop
Package javax.swing

Class JMenuItem

All Implemented Interfaces:
ImageObserver, ItemSelectable, MenuContainer, Serializable, Accessible, MenuElement, SwingConstants
Direct Known Subclasses:
JCheckBoxMenuItem, JMenu, JRadioButtonMenuItem

@JavaBean(defaultProperty="UIClassID",
          description="An item which can be selected in a menu.")
public class JMenuItem
extends AbstractButton
implements Accessible, MenuElement
An implementation of an item in a menu. A menu item is essentially a button sitting in a list. When the user selects the "button", the action associated with the menu item is performed. A JMenuItem contained in a JPopupMenu performs exactly that function.

Menu items can be configured, and to some degree controlled, by Actions. Using an Action with a menu item has many benefits beyond directly configuring a menu item. Refer to Swing Components Supporting Action for more details, and you can find more information in How to Use Actions, a section in The Java Tutorial.

For further documentation and for examples, see How to Use Menus 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.

Since:
1.2
See Also:
JPopupMenu, JMenu, JCheckBoxMenuItem, JRadioButtonMenuItem
  • Constructor Details

    • JMenuItem

      public JMenuItem()
      Creates a JMenuItem with no set text or icon.
    • JMenuItem

      public JMenuItem​(Icon icon)
      Creates a JMenuItem with the specified icon.
      Parameters:
      icon - the icon of the JMenuItem
    • JMenuItem

      public JMenuItem​(String text)
      Creates a JMenuItem with the specified text.
      Parameters:
      text - the text of the JMenuItem
    • JMenuItem

      public JMenuItem​(Action a)
      Creates a menu item whose properties are taken from the specified Action.
      Parameters:
      a - the action of the JMenuItem
      Since:
      1.3
    • JMenuItem

      public JMenuItem​(String text, Icon icon)
      Creates a JMenuItem with the specified text and icon.
      Parameters:
      text - the text of the JMenuItem
      icon - the icon of the JMenuItem
    • JMenuItem

      public JMenuItem​(String text, int mnemonic)
      Creates a JMenuItem with the specified text and keyboard mnemonic.
      Parameters:
      text - the text of the JMenuItem
      mnemonic - the keyboard mnemonic for the JMenuItem
  • Method Details

    • init

      protected void init​(String text, Icon icon)
      Initializes the menu item with the specified text and icon.
      Overrides:
      init in class AbstractButton
      Parameters:
      text - the text of the JMenuItem
      icon - the icon of the JMenuItem
    • setUI

      @BeanProperty(hidden=true, visualUpdate=true, description="The UI object that implements the LookAndFeel.") public void setUI​(MenuItemUI ui)
      Sets the look and feel object that renders this component.
      Parameters:
      ui - the JMenuItemUI 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 AbstractButton
      See Also:
      JComponent.updateUI()
    • getUIClassID

      @BeanProperty(bound=false) public String getUIClassID()
      Returns the suffix used to construct the name of the L&F class used to render this component.
      Overrides:
      getUIClassID in class JComponent
      Returns:
      the string "MenuItemUI"
      See Also:
      JComponent.getUIClassID(), UIDefaults.getUI(javax.swing.JComponent)
    • setArmed

      @BeanProperty(bound=false, hidden=true, description="Mouse release will fire an action event") public void setArmed​(boolean b)
      Identifies the menu item as "armed". If the mouse button is released while it is over this item, the menu's action event will fire. If the mouse button is released elsewhere, the event will not fire and the menu item will be disarmed.
      Parameters:
      b - true to arm the menu item so it can be selected
    • isArmed

      public boolean isArmed()
      Returns whether the menu item is "armed".
      Returns:
      true if the menu item is armed, and it can be selected
      See Also:
      setArmed(boolean)
    • setEnabled

      @BeanProperty(preferred=true, description="The enabled state of the component.") public void setEnabled​(boolean b)
      Enables or disables the menu item.
      Overrides:
      setEnabled in class AbstractButton
      Parameters:
      b - true to enable the item
      See Also:
      Component.isEnabled(), Component.isLightweight()
    • setAccelerator

      @BeanProperty(preferred=true, description="The keystroke combination which will invoke the JMenuItem\'s actionlisteners without navigating the menu hierarchy") public void setAccelerator​(KeyStroke keyStroke)
      Sets the key combination which invokes the menu item's action listeners without navigating the menu hierarchy. It is the UI's responsibility to install the correct action. Note that when the keyboard accelerator is typed, it will work whether or not the menu is currently displayed.
      Parameters:
      keyStroke - the KeyStroke which will serve as an accelerator
    • getAccelerator

      public KeyStroke getAccelerator()
      Returns the KeyStroke which serves as an accelerator for the menu item.
      Returns:
      a KeyStroke object identifying the accelerator key
    • configurePropertiesFromAction

      protected void configurePropertiesFromAction​(Action a)
      Sets the properties on this button to match those in the specified Action. Refer to Swing Components Supporting Action for more details as to which properties this sets.
      Overrides:
      configurePropertiesFromAction in class AbstractButton
      Parameters:
      a - the Action from which to get the properties, or null
      Since:
      1.3
      See Also:
      Action, AbstractButton.setAction(javax.swing.Action)
    • actionPropertyChanged

      protected void actionPropertyChanged​(Action action, String propertyName)
      Updates the button's state in response to property changes in the associated action. This method is invoked from the PropertyChangeListener returned from createActionPropertyChangeListener. Subclasses do not normally need to invoke this. Subclasses that support additional Action properties should override this and configurePropertiesFromAction.

      Refer to the table at Swing Components Supporting Action for a list of the properties this method sets.

      Overrides:
      actionPropertyChanged in class AbstractButton
      Parameters:
      action - the Action associated with this button
      propertyName - the name of the property that changed
      Since:
      1.6
      See Also:
      Action, AbstractButton.configurePropertiesFromAction(javax.swing.Action)
    • processMouseEvent

      public void processMouseEvent​(MouseEvent e, MenuElement[] path, MenuSelectionManager manager)
      Processes a mouse event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using the MenuSelectionManager's API.

      Note: you do not have to forward the event to sub-components. This is done automatically by the MenuSelectionManager.

      Specified by:
      processMouseEvent in interface MenuElement
      Parameters:
      e - a MouseEvent
      path - the MenuElement path array
      manager - the MenuSelectionManager
    • processKeyEvent

      public void processKeyEvent​(KeyEvent e, MenuElement[] path, MenuSelectionManager manager)
      Processes a key event forwarded from the MenuSelectionManager and changes the menu selection, if necessary, by using MenuSelectionManager's API.

      Note: you do not have to forward the event to sub-components. This is done automatically by the MenuSelectionManager.

      Specified by:
      processKeyEvent in interface MenuElement
      Parameters:
      e - a KeyEvent
      path - the MenuElement path array
      manager - the MenuSelectionManager
    • processMenuDragMouseEvent

      public void processMenuDragMouseEvent​(MenuDragMouseEvent e)
      Handles mouse drag in a menu.
      Parameters:
      e - a MenuDragMouseEvent object
    • processMenuKeyEvent

      public void processMenuKeyEvent​(MenuKeyEvent e)
      Handles a keystroke in a menu.
      Parameters:
      e - a MenuKeyEvent object
    • fireMenuDragMouseEntered

      protected void fireMenuDragMouseEntered​(MenuDragMouseEvent event)
      Notifies all listeners that have registered interest for notification on this event type.
      Parameters:
      event - a MenuMouseDragEvent
      See Also:
      EventListenerList
    • fireMenuDragMouseExited

      protected void fireMenuDragMouseExited​(MenuDragMouseEvent event)
      Notifies all listeners that have registered interest for notification on this event type.
      Parameters:
      event - a MenuDragMouseEvent
      See Also:
      EventListenerList
    • fireMenuDragMouseDragged

      protected void fireMenuDragMouseDragged​(MenuDragMouseEvent event)
      Notifies all listeners that have registered interest for notification on this event type.
      Parameters:
      event - a MenuDragMouseEvent
      See Also:
      EventListenerList
    • fireMenuDragMouseReleased

      protected void fireMenuDragMouseReleased​(MenuDragMouseEvent event)
      Notifies all listeners that have registered interest for notification on this event type.
      Parameters:
      event - a MenuDragMouseEvent
      See Also:
      EventListenerList
    • fireMenuKeyPressed

      protected void fireMenuKeyPressed​(MenuKeyEvent event)
      Notifies all listeners that have registered interest for notification on this event type.
      Parameters:
      event - a MenuKeyEvent
      See Also:
      EventListenerList
    • fireMenuKeyReleased

      protected void fireMenuKeyReleased​(MenuKeyEvent event)
      Notifies all listeners that have registered interest for notification on this event type.
      Parameters:
      event - a MenuKeyEvent
      See Also:
      EventListenerList
    • fireMenuKeyTyped

      protected void fireMenuKeyTyped​(MenuKeyEvent event)
      Notifies all listeners that have registered interest for notification on this event type.
      Parameters:
      event - a MenuKeyEvent
      See Also:
      EventListenerList
    • getSubElements

      @BeanProperty(bound=false) public MenuElement[] getSubElements()
      This method returns an array containing the sub-menu components for this menu component.
      Specified by:
      getSubElements in interface MenuElement
      Returns:
      an array of MenuElements
    • getComponent

      public Component getComponent()
      Returns the java.awt.Component used to paint this object. The returned component will be used to convert events and detect if an event is inside a menu component.
      Specified by:
      getComponent in interface MenuElement
      Returns:
      the Component that paints this menu item
    • addMenuDragMouseListener

      public void addMenuDragMouseListener​(MenuDragMouseListener l)
      Adds a MenuDragMouseListener to the menu item.
      Parameters:
      l - the MenuDragMouseListener to be added
    • removeMenuDragMouseListener

      public void removeMenuDragMouseListener​(MenuDragMouseListener l)
      Removes a MenuDragMouseListener from the menu item.
      Parameters:
      l - the MenuDragMouseListener to be removed
    • getMenuDragMouseListeners

      @BeanProperty(bound=false) public MenuDragMouseListener[] getMenuDragMouseListeners()
      Returns an array of all the MenuDragMouseListeners added to this JMenuItem with addMenuDragMouseListener().
      Returns:
      all of the MenuDragMouseListeners added or an empty array if no listeners have been added
      Since:
      1.4
    • addMenuKeyListener

      public void addMenuKeyListener​(MenuKeyListener l)
      Adds a MenuKeyListener to the menu item.
      Parameters:
      l - the MenuKeyListener to be added
    • removeMenuKeyListener

      public void removeMenuKeyListener​(MenuKeyListener l)
      Removes a MenuKeyListener from the menu item.
      Parameters:
      l - the MenuKeyListener to be removed
    • getMenuKeyListeners

      @BeanProperty(bound=false) public MenuKeyListener[] getMenuKeyListeners()
      Returns an array of all the MenuKeyListeners added to this JMenuItem with addMenuKeyListener().
      Returns:
      all of the MenuKeyListeners added or an empty array if no listeners have been added
      Since:
      1.4
    • paramString

      protected String paramString()
      Returns a string representation of this JMenuItem. 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 AbstractButton
      Returns:
      a string representation of this JMenuItem
    • getAccessibleContext

      @BeanProperty(bound=false) public AccessibleContext getAccessibleContext()
      Returns the AccessibleContext associated with this JMenuItem. For JMenuItems, the AccessibleContext takes the form of an AccessibleJMenuItem. A new AccessibleJMenuItme instance is created if necessary.
      Specified by:
      getAccessibleContext in interface Accessible
      Overrides:
      getAccessibleContext in class Component
      Returns:
      an AccessibleJMenuItem that serves as the AccessibleContext of this JMenuItem