Java java.awt Class Menu（JDK8）

Constructor Detail

• Menu

  public Menu()
       throws HeadlessException

  Constructs a new menu with an empty label. This menu is not a tear-off menu.

  Throws:

  HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

  Since:

  JDK1.1

  See Also:

  GraphicsEnvironment.isHeadless()

• Menu

  public Menu(String label)
       throws HeadlessException

  Constructs a new menu with the specified label. This menu is not a tear-off menu.

  Parameters:

  label - the menu's label in the menu bar, or in another menu of which this menu is a submenu.

  Throws:

  HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

  See Also:

  GraphicsEnvironment.isHeadless()

• Menu

  public Menu(String label,
              boolean tearOff)
       throws HeadlessException

  Constructs a new menu with the specified label, indicating whether the menu can be torn off.

  Tear-off functionality may not be supported by all implementations of AWT. If a particular implementation doesn't support tear-off menus, this value is silently ignored.

  Parameters:

  label - the menu's label in the menu bar, or in another menu of which this menu is a submenu.

  tearOff - if true, the menu is a tear-off menu.

  Throws:

  HeadlessException - if GraphicsEnvironment.isHeadless() returns true.

  Since:

  JDK1.0.

  See Also:

  GraphicsEnvironment.isHeadless()

Method Detail

• addNotify

  public void addNotify()

  Creates the menu's peer. The peer allows us to modify the appearance of the menu without changing its functionality.

  Overrides:

  addNotify in class MenuItem

• removeNotify

  public void removeNotify()

  Removes the menu's peer. The peer allows us to modify the appearance of the menu without changing its functionality.

  Overrides:

  removeNotify in class MenuComponent

• isTearOff

  public boolean isTearOff()

  Indicates whether this menu is a tear-off menu.

  Tear-off functionality may not be supported by all implementations of AWT. If a particular implementation doesn't support tear-off menus, this value is silently ignored.

  Returns:

  true if this is a tear-off menu; false otherwise.

• getItemCount

  public int getItemCount()

  Get the number of items in this menu.

  Returns:

  the number of items in this menu.

  Since:

  JDK1.1

• countItems

  @Deprecated
  public int countItems()

  Deprecated. As of JDK version 1.1, replaced by getItemCount().

• getItem

  public MenuItem getItem(int index)

  Gets the item located at the specified index of this menu.

  Parameters:

  index - the position of the item to be returned.

  Returns:

  the item located at the specified index.

• add

  public MenuItem add(MenuItem mi)

  Adds the specified menu item to this menu. If the menu item has been part of another menu, removes it from that menu.

  Parameters:

  mi - the menu item to be added

  Returns:

  the menu item added

  See Also:

  insert(java.lang.String, int), insert(java.awt.MenuItem, int)

• add

  public void add(String label)

  Adds an item with the specified label to this menu.

  Parameters:

  label - the text on the item

  See Also:

  insert(java.lang.String, int), insert(java.awt.MenuItem, int)

• insert

  public void insert(MenuItem menuitem,
                     int index)

  Inserts a menu item into this menu at the specified position.

  Parameters:

  menuitem - the menu item to be inserted.

  index - the position at which the menu item should be inserted.

  Throws:

  IllegalArgumentException - if the value of index is less than zero

  Since:

  JDK1.1

  See Also:

  add(java.lang.String), add(java.awt.MenuItem)

• insert

  public void insert(String label,
                     int index)

  Inserts a menu item with the specified label into this menu at the specified position. This is a convenience method for insert(menuItem, index).

  Parameters:

  label - the text on the item

  index - the position at which the menu item should be inserted

  Throws:

  IllegalArgumentException - if the value of index is less than zero

  Since:

  JDK1.1

  See Also:

  add(java.lang.String), add(java.awt.MenuItem)

• addSeparator

  public void addSeparator()

  Adds a separator line, or a hypen, to the menu at the current position.

  See Also:

  insertSeparator(int)

• insertSeparator

  public void insertSeparator(int index)

  Inserts a separator at the specified position.

  Parameters:

  index - the position at which the menu separator should be inserted.

  Throws:

  IllegalArgumentException - if the value of index is less than 0.

  Since:

  JDK1.1

  See Also:

  addSeparator()

• remove

  public void remove(int index)

  Removes the menu item at the specified index from this menu.

  Parameters:

  index - the position of the item to be removed.

• remove

  public void remove(MenuComponent item)

  Removes the specified menu item from this menu.

  Specified by:

  remove in interface MenuContainer

  Parameters:

  item - the item to be removed from the menu. If item is null or is not in this menu, this method does nothing.

• removeAll

  public void removeAll()

  Removes all items from this menu.

  Since:

  JDK1.0.

• paramString

  public String paramString()

  Returns a string representing the state of this Menu. 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 MenuItem

  Returns:

  the parameter string of this menu

• getAccessibleContext

  public AccessibleContext getAccessibleContext()

  Gets the AccessibleContext associated with this Menu. For menus, the AccessibleContext takes the form of an AccessibleAWTMenu. A new AccessibleAWTMenu instance is created if necessary.

  Specified by:

  getAccessibleContext in interface Accessible

  Overrides:

  getAccessibleContext in class MenuItem

  Returns:

  an AccessibleAWTMenu that serves as the AccessibleContext of this Menu

  Since:

  1.3