Menu (Java 2 Platform SE v1.4.1) - JDK 5 Documentation v1.4.1, Java 2 SDK 英文文档

Overview

Package

Class

Use

Tree

Deprecated

Index

Help

Java^TM 2 Platform
Std. Ed. v1.4.1

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

java.awt
Class Menu

java.lang.Object
  |
  +--java.awt.MenuComponent
        |
        +--java.awt.MenuItem
              |
              +--java.awt.Menu

All Implemented Interfaces:: Accessible, MenuContainer, Serializable

Direct Known Subclasses:: PopupMenu

public class Menu
extends MenuItem
implements MenuContainer, Accessible

A Menu object is a pull-down menu component that is deployed from a menu bar.

A menu can optionally be a tear-off menu. A tear-off menu can be opened and dragged away from its parent menu bar or menu. It remains on the screen after the mouse button has been released. The mechanism for tearing off a menu is platform dependent, since the look and feel of the tear-off menu is determined by its peer. On platforms that do not support tear-off menus, the tear-off property is ignored.

Each item in a menu must belong to the MenuItem class. It can be an instance of MenuItem, a submenu (an instance of Menu), or a check box (an instance of CheckboxMenuItem).

Since:: JDK1.0
See Also:: MenuItem, CheckboxMenuItem, Serialized Form

Nested Class Summary

protected class Menu.AccessibleAWTMenu
          Inner class of Menu used to provide default support for accessibility.

Nested classes inherited from class java.awt.MenuItem

Nested classes inherited from class java.awt.MenuComponent

Constructor Summary

Menu()
          Constructs a new menu with an empty label.

Menu(String label)
          Constructs a new menu with the specified label.

Menu(String label, boolean tearOff)
          Constructs a new menu with the specified label, indicating whether the menu can be torn off.

Method Summary

MenuItem add(MenuItem mi)
          Adds the specified menu item to this menu.

void add(String label)
          Adds an item with the specified label to this menu.

void addNotify()
          Creates the menu's peer.

void addSeparator()
          Adds a separator line, or a hypen, to the menu at the current position.

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

AccessibleContext getAccessibleContext()
          Gets the AccessibleContext associated with this Menu.

MenuItem getItem(int index)
          Gets the item located at the specified index of this menu.

int getItemCount()
          Get the number of items in this menu.

void insert(MenuItem menuitem, int index)
          Inserts a menu item into this menu at the specified position.

void insert(String label, int index)
          Inserts a menu item with the specified label into this menu at the specified position.

void insertSeparator(int index)
          Inserts a separator at the specified position.

boolean isTearOff()
          Indicates whether this menu is a tear-off menu.

String paramString()
          Returns a string representing the state of this Menu.

void remove(int index)
          Removes the menu item at the specified index from this menu.

void remove(MenuComponent item)
          Removes the specified menu item from this menu.

void removeAll()
          Removes all items from this menu.

void removeNotify()
          Removes the menu's peer.

Methods inherited from class java.awt.MenuItem

addActionListener, deleteShortcut, disable, disableEvents, enable, enable, enableEvents, getActionCommand, getActionListeners, getLabel, getListeners, getShortcut, isEnabled, processActionEvent, processEvent, removeActionListener, setActionCommand, setEnabled, setLabel, setShortcut

Methods inherited from class java.awt.MenuComponent

dispatchEvent, getFont, getName, getParent, getPeer, getTreeLock, postEvent, setFont, setName, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.awt.MenuContainer

getFont, postEvent

Constructor Detail

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()

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

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

Overview

Package

Class

Use

Tree

Deprecated

Index

Help

Java^TM 2 Platform
Std. Ed. v1.4.1

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Nested Class Summary
`protected class`	`Menu.AccessibleAWTMenu` Inner class of Menu used to provide default support for accessibility.

Constructor Summary
`Menu()` Constructs a new menu with an empty label.
`Menu(String label)` Constructs a new menu with the specified label.
`Menu(String label, boolean tearOff)` Constructs a new menu with the specified label, indicating whether the menu can be torn off.

Method Summary
`MenuItem`	`add(MenuItem mi)` Adds the specified menu item to this menu.
`void`	`add(String label)` Adds an item with the specified label to this menu.
`void`	`addNotify()` Creates the menu's peer.
`void`	`addSeparator()` Adds a separator line, or a hypen, to the menu at the current position.
`int`	`countItems()` Deprecated. As of JDK version 1.1, replaced by `getItemCount()`.
`AccessibleContext`	`getAccessibleContext()` Gets the AccessibleContext associated with this Menu.
`MenuItem`	`getItem(int index)` Gets the item located at the specified index of this menu.
`int`	`getItemCount()` Get the number of items in this menu.
`void`	`insert(MenuItem menuitem, int index)` Inserts a menu item into this menu at the specified position.
`void`	`insert(String label, int index)` Inserts a menu item with the specified label into this menu at the specified position.
`void`	`insertSeparator(int index)` Inserts a separator at the specified position.
`boolean`	`isTearOff()` Indicates whether this menu is a tear-off menu.
`String`	`paramString()` Returns a string representing the state of this `Menu`.
`void`	`remove(int index)` Removes the menu item at the specified index from this menu.
`void`	`remove(MenuComponent item)` Removes the specified menu item from this menu.
`void`	`removeAll()` Removes all items from this menu.
`void`	`removeNotify()` Removes the menu's peer.

Menu (Java 2 Platform SE v1.4.1) - JDK 5 Documentation v1.4.1, Java 2 SDK 英文文档

java.awt Class Menu

Menu

Menu

Menu

addNotify

removeNotify

isTearOff

getItemCount

countItems

getItem

add

add

insert

insert

addSeparator

insertSeparator

remove

remove

removeAll

paramString

getAccessibleContext

java.awt
Class Menu