/*
* @(#)MenuComponent.java 1.14 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package java.awt;
import java.awt.event.ActionEvent;
/**
* The abstract class <code>MenuComponent</code> is the superclass
* of all menu-related components. In this respect, the class
* <code>MenuComponent</code> is analogous to the abstract superclass
* <code>Component</code> for AWT components.
* <p>
* Menu components receive and process AWT events, just as components do,
* through the method <code>processEvent</code>.
*
* @version 1.3, 08/22/01
* @author Arthur van Hoff
* @since JDK1.0
*/
public abstract class MenuComponent implements java.io.Serializable {
transient MenuContainer parent;
Font font;
private String name;
private boolean nameExplicitlySet = false;
boolean newEventsOnly = false;
/*
* Internal constants for serialization
*/
final static String actionListenerK = Component.actionListenerK;
final static String itemListenerK = Component.itemListenerK;
/*
* JDK 1.1 serialVersionUID
*/
private static final long serialVersionUID = -4536902356223894379L;
/**
* Construct a name for this MenuComponent. Called by getName() when
* the name is null.
*/
String constructComponentName() {
return null; // For strict compliance with prior JDKs, a MenuComponent
// that doesn't set its name should return null from
// getName()
}
/**
* Gets the name of the menu component.
* @return the name of the menu component.
* @see java.awt.MenuComponent#setName(java.lang.String)
* @since JDK1.1
*/
public String getName() {
if (name == null && !nameExplicitlySet) {
synchronized (this) {
if (name == null && !nameExplicitlySet) {
name = constructComponentName();
}
}
}
return name;
}
/**
* Sets the name of the component to the specified string.
* @param name the name of the menu component.
* @see java.awt.MenuComponent#getName
* @since JDK1.1
*/
public void setName(String name) {
synchronized (this) {
this.name = name;
nameExplicitlySet = true;
}
}
/**
* Returns the parent container for this menu component.
* @return the menu component containing this menu component,
* or <code>null</code> if this menu component
* is the outermost component, the menu bar itself.
* @since JDK1.0
*/
public MenuContainer getParent() {
return parent;
}
/**
* Gets the font used for this menu component.
* @return the font used in this menu component, if there is one;
* <code>null</code> otherwise.
* @see java.awt.MenuComponent#setFont
* @since JDK1.0
*/
public Font getFont() {
Font font = this.font;
if (font != null) {
return font;
}
MenuContainer parent = this.parent;
if (parent != null) {
return parent.getFont();
}
return null;
}
/**
* 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.
* @param f the font to be set.
* @see java.awt.MenuComponent#getFont
* @since JDK1.0
*/
public void setFont(Font f) {
font = f;
}
/**
* 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.
*/
public void removeNotify() {}
/*
* Delivers an event to this component or one of its sub components.
* @param e the event
*/
public final void dispatchEvent(AWTEvent e) {
dispatchEventImpl(e);
}
void dispatchEventImpl(AWTEvent e) {
if ((parent != null && parent instanceof MenuComponent &&
((MenuComponent) parent).newEventsOnly)) {
if (eventEnabled(e)) {
processEvent(e);
} else if (e instanceof ActionEvent && parent != null) {
((MenuComponent) parent).dispatchEvent(new ActionEvent(parent,
e.getID(),
((ActionEvent) e).getActionCommand()));
}
}
}
// NOTE: remove when filtering is done at lower level
boolean eventEnabled(AWTEvent e) {
return false;
}
/**
* Processes events occurring on this menu component.
* @param e the event
* @since JDK1.1
*/
protected void processEvent(AWTEvent e) {}
/**
* Returns the parameter string representing the state of this
* menu component. This string is useful for debugging.
* @return the parameter string of this menu component.
* @since JDK1.0
*/
protected String paramString() {
String thisName = getName();
return (thisName != null ? thisName : "");
}
/**
* Returns a representation of this menu component as a string.
* @return a string representation of this menu component.
* @since JDK1.0
*/
public String toString() {
return getClass().getName() + "[" + paramString() + "]";
}
/**
* Gets this component's locking object (the object that owns the thread
* sychronization monitor) for AWT component-tree and layout
* operations.
* @return This component's locking object.
*/
protected final Object getTreeLock() {
return Component.LOCK;
}
}