Class MenuComponent

java.lang.Object

java.awt.MenuComponent

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

MenuBar, MenuItem

public abstract class MenuComponent
extends Object
implements Serializable

The abstract class MenuComponent is the superclass of all menu-related components. In this respect, the class MenuComponent is analogous to the abstract superclass Component for AWT components.

Menu components receive and process AWT events, just as components do, through the method processEvent.

Since:

1.0

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	MenuComponent.AccessibleAWTMenuComponent	Inner class of MenuComponent used to provide default support for accessibility.

Constructor Summary

Constructors

Constructor	Description
MenuComponent()	Creates a MenuComponent.

Method Summary

Modifier and Type	Method	Description
final void	dispatchEvent(AWTEvent e)	Delivers an event to this component or one of its sub components.
AccessibleContext	getAccessibleContext()	Gets the AccessibleContext associated with this MenuComponent.
Font	getFont()	Gets the font used for this menu component.
String	getName()	Gets the name of the menu component.
MenuContainer	getParent()	Returns the parent container for this menu component.
protected final Object	getTreeLock()	Gets this component's locking object (the object that owns the thread synchronization monitor) for AWT component-tree and layout operations.
protected String	paramString()	Returns a string representing the state of this MenuComponent.
boolean	postEvent(Event evt)	Deprecated. As of JDK version 1.1, replaced by dispatchEvent.
protected void	processEvent(AWTEvent e)	Processes events occurring on this menu component.
void	removeNotify()	Removes the menu component's peer.
void	setFont(Font f)	Sets the font to be used for this menu component to the specified font.
void	setName(String name)	Sets the name of the component to the specified string.
String	toString()	Returns a representation of this menu component as a string.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details

MenuComponent

public MenuComponent()
              throws HeadlessException

Creates a MenuComponent.

Throws:

HeadlessException - if GraphicsEnvironment.isHeadless returns true

See Also:

• GraphicsEnvironment.isHeadless()

Method Details

getName

public String getName()

Gets the name of the menu component.

Returns:

the name of the menu component

Since:

1.1

See Also:

• setName(java.lang.String)

setName

public void setName(String name)

Sets the name of the component to the specified string.

Parameters:

name - the name of the menu component

Since:

1.1

See Also:

• getName()

getParent

public MenuContainer getParent()

Returns the parent container for this menu component.

Returns:

the menu component containing this menu component, or null if this menu component is the outermost component, the menu bar itself

getFont

public Font getFont()

Gets the font used for this menu component.

Returns:

the font used in this menu component, if there is one; null otherwise

See Also:

• setFont(Font)

setFont

public void setFont(Font f)

Sets the font to be used for this menu component to the specified font. This font is also used by all subcomponents of this menu component, unless those subcomponents specify a different font.

Some platforms may not support setting of all font attributes of a menu component; in such cases, calling setFont will have no effect on the unsupported font attributes of this menu component. Unless subcomponents of this menu component specify a different font, this font will be used by those subcomponents if supported by the underlying platform.

Parameters:

f - the font to be set

See Also:

• getFont()
• Font.getAttributes()
• TextAttribute

removeNotify

public void removeNotify()

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

postEvent

@Deprecated
public boolean postEvent(Event evt)

Deprecated.

As of JDK version 1.1, replaced by dispatchEvent.

Posts the specified event to the menu. This method is part of the Java 1.0 event system and it is maintained only for backwards compatibility. Its use is discouraged, and it may not be supported in the future.

Parameters:

evt - the event which is to take place

Returns:

unconditionally returns false

dispatchEvent

public final void dispatchEvent(AWTEvent e)

Delivers an event to this component or one of its sub components.

Parameters:

e - the event

processEvent

protected void processEvent(AWTEvent e)

Processes events occurring on this menu component.

Note that if the event parameter is null the behavior is unspecified and may result in an exception.

Parameters:

e - the event

Since:

1.1

paramString

protected String paramString()

Returns a string representing the state of this MenuComponent. 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.

Returns:

the parameter string of this menu component

toString

public String toString()

Returns a representation of this menu component as a string.

Overrides:

toString in class Object

Returns:

a string representation of this menu component

getTreeLock

protected final Object getTreeLock()

Gets this component's locking object (the object that owns the thread synchronization monitor) for AWT component-tree and layout operations.

Returns:

this component's locking object

getAccessibleContext

public AccessibleContext getAccessibleContext()

Gets the AccessibleContext associated with this MenuComponent. The method implemented by this base class returns null. Classes that extend MenuComponent should implement this method to return the AccessibleContext associated with the subclass.

Returns:

the AccessibleContext of this MenuComponent

Since:

1.3