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| java.lang.Object
 java.awt.MenuComponent
java.awt.MenuItem
All known Subclasses: java.awt.Menu, java.awt.CheckboxMenuItem,
| MenuItem | | public class MenuItem extends MenuComponent implements Accessible(Code) | | All items in a menu must belong to the class
MenuItem, or one of its subclasses.
The default MenuItem object embodies
a simple labeled menu item.
This picture of a menu bar shows five menu items:
The first two items are simple menu items, labeled
"Basic" and "Simple".
Following these two items is a separator, which is itself
a menu item, created with the label "-".
Next is an instance of CheckboxMenuItem
labeled "Check". The final menu item is a
submenu labeled "More Examples",
and this submenu is an instance of Menu.
When a menu item is selected, AWT sends an action event to
the menu item. Since the event is an
instance of ActionEvent, the processEvent
method examines the event and passes it along to
processActionEvent. The latter method redirects the
event to any ActionListener objects that have
registered an interest in action events generated by this
menu item.
Note that the subclass Menu overrides this behavior and
does not send any event to the frame until one of its subitems is
selected.
version:
1.101, 05/05/07
author:
Sami Shaio |
| Constructor Summary | |
| public | MenuItem()
Constructs a new MenuItem with an empty label and no keyboard
shortcut. | | public | MenuItem(String label)
Constructs a new MenuItem with the specified label
and no keyboard shortcut. | | public | MenuItem(String label, MenuShortcut s)
Create a menu item with an associated keyboard shortcut.
Note that use of "-" in a label is reserved to indicate
a separator between menu items. |
| Method Summary | |
| public synchronized void | addActionListener(ActionListener l)
Adds the specified action listener to receive action events
from this menu item. | | public void | addNotify()
Creates the menu item's peer. | | String | constructComponentName()
Construct a name for this MenuComponent. | | public void | deleteShortcut()
Delete any MenuShortcut object associated
with this menu item. | | void | deleteShortcut(MenuShortcut s)
| | public synchronized void | disable()
| | final protected void | disableEvents(long eventsToDisable)
Disables event delivery to this menu item for events
defined by the specified event mask parameter. | | void | doMenuEvent(long when, int modifiers)
| | public synchronized void | enable()
| | public void | enable(boolean b)
| | final protected void | enableEvents(long eventsToEnable)
Enables event delivery to this menu item for events
to be defined by the specified event mask parameter
Since event types are automatically enabled when a listener for
that type is added to the menu item, this method only needs
to be invoked by subclasses of MenuItem which desire to
have the specified event types delivered to processEvent
regardless of whether a listener is registered. | | boolean | eventEnabled(AWTEvent e)
| | public AccessibleContext | getAccessibleContext()
Gets the AccessibleContext associated with this MenuItem. | | public String | getActionCommand()
Gets the command name of the action event that is fired
by this menu item. | | final String | getActionCommandImpl()
| | public synchronized ActionListener[] | getActionListeners()
Returns an array of all the action listeners
registered on this menu item. | | public String | getLabel()
Gets the label for this menu item. | | public T[] | getListeners(Class<T> listenerType)
Returns an array of all the objects currently registered
as FooListeners
upon this MenuItem. | | public MenuShortcut | getShortcut()
| | MenuItem | getShortcutMenuItem(MenuShortcut s)
| | boolean | handleShortcut(KeyEvent e)
| | public boolean | isEnabled()
Checks whether this menu item is enabled. | | public String | paramString()
Returns a string representing the state of this MenuItem.
This method is intended to be used only for debugging purposes, and the
content and format of the returned string may vary between
implementations. | | protected void | processActionEvent(ActionEvent e)
Processes action events occurring on this menu item,
by dispatching them to any registered
ActionListener objects.
This method is not called unless action events are
enabled for this component. | | protected void | processEvent(AWTEvent e)
Processes events on this menu item. | | public synchronized void | removeActionListener(ActionListener l)
Removes the specified action listener so it no longer receives
action events from this menu item. | | public void | setActionCommand(String command)
Sets the command name of the action event that is fired
by this menu item. | | public synchronized void | setEnabled(boolean b)
Sets whether or not this menu item can be chosen. | | public synchronized void | setLabel(String label)
Sets the label for this menu item to the specified label. | | public void | setShortcut(MenuShortcut s)
Set the MenuShortcut object associated with this
menu item. |
| eventMask | | long eventMask(Code) | | The eventMask is ONLY set by subclasses via enableEvents.
The mask should NOT be set when listeners are registered
so that we can distinguish the difference between when
listeners request events and subclasses request them.
|
| MenuItem | | public MenuItem(String label) throws HeadlessException(Code) | | Constructs a new MenuItem with the specified label
and no keyboard shortcut. Note that use of "-" in
a label is reserved to indicate a separator between
menu items. By default, all menu items except for
separators are enabled.
Parameters:
label - the label for this menu item.
exception:
HeadlessException - if GraphicsEnvironment.isHeadless()returns true.
See Also: java.awt.GraphicsEnvironment.isHeadless
since:
JDK1.0 |
| MenuItem | | public MenuItem(String label, MenuShortcut s) throws HeadlessException(Code) | | Create a menu item with an associated keyboard shortcut.
Note that use of "-" in a label is reserved to indicate
a separator between menu items. By default, all menu
items except for separators are enabled.
Parameters:
label - the label for this menu item.
Parameters:
s - the instance of MenuShortcutassociated with this menu item.
exception:
HeadlessException - if GraphicsEnvironment.isHeadless()returns true.
See Also: java.awt.GraphicsEnvironment.isHeadless
since:
JDK1.1 |
| addNotify | | public void addNotify()(Code) | | Creates the menu item's peer. The peer allows us to modify the
appearance of the menu item without changing its functionality.
|
| constructComponentName | | String constructComponentName()(Code) | | Construct a name for this MenuComponent. Called by getName() when
the name is null.
|
| deleteShortcut | | public void deleteShortcut()(Code) | | Delete any MenuShortcut object associated
with this menu item.
since:
JDK1.1 |
| disable | | public synchronized void disable()(Code) | | |
| doMenuEvent | | void doMenuEvent(long when, int modifiers)(Code) | | |
| enable | | public synchronized void enable()(Code) | | |
| enable | | public void enable(boolean b)(Code) | | |
| enableEvents | | final protected void enableEvents(long eventsToEnable)(Code) | | Enables event delivery to this menu item for events
to be defined by the specified event mask parameter
Since event types are automatically enabled when a listener for
that type is added to the menu item, this method only needs
to be invoked by subclasses of MenuItem which desire to
have the specified event types delivered to processEvent
regardless of whether a listener is registered.
Parameters:
eventsToEnable - the event mask defining the event types
See Also: java.awt.MenuItem.processEvent
See Also: java.awt.MenuItem.disableEvents
See Also: java.awt.Component.enableEvents
since:
JDK1.1 |
| getAccessibleContext | | public AccessibleContext getAccessibleContext()(Code) | | Gets the AccessibleContext associated with this MenuItem.
For menu items, the AccessibleContext takes the form of an
AccessibleAWTMenuItem.
A new AccessibleAWTMenuItem instance is created if necessary.
an AccessibleAWTMenuItem that serves as the AccessibleContext of this MenuItem
since:
1.3 |
| getActionCommandImpl | | final String getActionCommandImpl()(Code) | | |
| getLabel | | public String getLabel()(Code) | | Gets the label for this menu item.
the label of this menu item, or nullif this menu item has no label.
See Also: java.awt.MenuItem.setLabel
since:
JDK1.0 |
| getListeners | | public T[] getListeners(Class<T> listenerType)(Code) | | Returns an array of all the objects currently registered
as FooListeners
upon this MenuItem.
FooListeners are registered using the
addFooListener method.
You can specify the listenerType argument
with a class literal, such as
FooListener.class.
For example, you can query a
MenuItem m
for its action listeners with the following code:
ActionListener[] als = (ActionListener[])(m.getListeners(ActionListener.class));
If no such listeners exist, this method returns an empty array.
Parameters:
listenerType - the type of listeners requested; this parametershould specify an interface that descends fromjava.util.EventListener an array of all objects registered asFooListeners on this menu item,or an empty array if no suchlisteners have been added
exception:
ClassCastException - if listenerTypedoesn't specify a class or interface that implementsjava.util.EventListener
See Also: MenuItem.getActionListeners
since:
1.3 |
| getShortcut | | public MenuShortcut getShortcut()(Code) | | Get the MenuShortcut object associated with this
menu item,
the menu shortcut associated with this menu item,or null if none has been specified.
See Also: java.awt.MenuItem.setShortcut
since:
JDK1.1 |
| paramString | | public String paramString()(Code) | | Returns a string representing the state of this MenuItem.
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.
the parameter string of this menu item |
| processActionEvent | | protected void processActionEvent(ActionEvent e)(Code) | | Processes action events occurring on this menu item,
by dispatching them to any registered
ActionListener objects.
This method is not called unless action events are
enabled for this component. Action events are enabled
when one of the following occurs:
- An
ActionListener object is registered
via addActionListener.
- Action events are enabled via
enableEvents.
Note that if the event parameter is null
the behavior is unspecified and may result in an
exception.
Parameters:
e - the action event
See Also: java.awt.event.ActionEvent
See Also: java.awt.event.ActionListener
See Also: java.awt.MenuItem.enableEvents
since:
JDK1.1 |
| processEvent | | protected void processEvent(AWTEvent e)(Code) | | Processes events on this menu item. If the event is an
instance of ActionEvent, it invokes
processActionEvent, another method
defined by MenuItem.
Currently, menu items only support action events.
Note that if the event parameter is null
the behavior is unspecified and may result in an
exception.
Parameters:
e - the event
See Also: java.awt.MenuItem.processActionEvent
since:
JDK1.1 |
| setActionCommand | | public void setActionCommand(String command)(Code) | | Sets the command name of the action event that is fired
by this menu item.
By default, the action command is set to the label of
the menu item.
Parameters:
command - the action command to be setfor this menu item.
See Also: java.awt.MenuItem.getActionCommand
since:
JDK1.1 |
| setEnabled | | public synchronized void setEnabled(boolean b)(Code) | | Sets whether or not this menu item can be chosen.
Parameters:
b - if true, enables this menu item;if false, disables it.
See Also: java.awt.MenuItem.isEnabled
since:
JDK1.1 |
| setLabel | | public synchronized void setLabel(String label)(Code) | | Sets the label for this menu item to the specified label.
Parameters:
label - the new label, or null for no label.
See Also: java.awt.MenuItem.getLabel
since:
JDK1.0 |
| setShortcut | | public void setShortcut(MenuShortcut s)(Code) | | Set the MenuShortcut object associated with this
menu item. If a menu shortcut is already associated with
this menu item, it is replaced.
Parameters:
s - the menu shortcut to associatewith this menu item.
See Also: java.awt.MenuItem.getShortcut
since:
JDK1.1 |
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