java.beans

Class EventSetDescriptor


public class EventSetDescriptor
extends FeatureDescriptor

EventSetDescriptor describes the hookup between an event source class and an event listener class. EventSets have several attributes: the listener class, the events that can be fired to the listener (methods in the listener class), and an add and remove listener method from the event firer's class.

The methods have these constraints on them:

A final constraint is that event listener classes must extend from EventListener.

There are also various design patterns associated with some of the methods of construction. Those are explained in more detail in the appropriate constructors.

Documentation Convention: for proper Internalization of Beans inside an RAD tool, sometimes there are two names for a property or method: a programmatic, or locale-independent name, which can be used anywhere, and a localized, display name, for ease of use. In the documentation I will specify different String values as either programmatic or localized to make this distinction clear.

Since:
JDK1.1

Constructor Summary

EventSetDescriptor(Class eventSourceClass, String eventSetName, Class listenerType, String listenerMethodName)
Create a new EventSetDescriptor.
EventSetDescriptor(Class eventSourceClass, String eventSetName, Class listenerType, String[] listenerMethodNames, String addListenerMethodName, String removeListenerMethodName)
Create a new EventSetDescriptor.
EventSetDescriptor(String eventSetName, Class listenerType, MethodDescriptor[] listenerMethodDescriptors, Method addListenerMethod, Method removeListenerMethod)
Create a new EventSetDescriptor.
EventSetDescriptor(String eventSetName, Class listenerType, Method[] listenerMethods, Method addListenerMethod, Method removeListenerMethod)
Create a new EventSetDescriptor.

Method Summary

Method
getAddListenerMethod()
Get the add listener method.
MethodDescriptor[]
getListenerMethodDescriptors()
Get the event firing methods as MethodDescriptors.
Method[]
getListenerMethods()
Get the event firing methods.
Class
getListenerType()
Get the class that contains the event firing methods.
Method
getRemoveListenerMethod()
Get the remove listener method.
boolean
isInDefaultEventSet()
Get whether or not this is in the default event set.
boolean
isUnicast()
Get whether or not multiple listeners may be added.
void
setInDefaultEventSet(boolean inDefaultEventSet)
Set whether or not this is in the default event set.
void
setUnicast(boolean unicast)
Set whether or not multiple listeners may be added.

Methods inherited from class java.beans.FeatureDescriptor

attributeNames, getDisplayName, getName, getShortDescription, getValue, isExpert, isHidden, isPreferred, setDisplayName, setExpert, setHidden, setName, setPreferred, setShortDescription, setValue

Methods inherited from class java.lang.Object

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

Constructor Details

EventSetDescriptor

public EventSetDescriptor(Class eventSourceClass,
                          String eventSetName,
                          Class listenerType,
                          String listenerMethodName)
            throws IntrospectionException
Create a new EventSetDescriptor. This version of the constructor enforces the rules imposed on the methods described at the top of this class, as well as searching for:

  1. The event-firing method must be non-private with signature void <listenerMethodName>(<eventSetName>Event) (where <eventSetName> has its first character capitalized by the constructor and the Event is a descendant of java.util.EventObject) in class listenerType (any exceptions may be thrown). Implementation note: Note that there could conceivably be multiple methods with this type of signature (example: java.util.MouseEvent vs. my.very.own.MouseEvent). In this implementation, all methods fitting the description will be put into the EventSetDescriptor, even though the spec says only one should be chosen (they probably weren't thinking as pathologically as I was). I don't like arbitrarily choosing things. If your class has only one such signature, as most do, you'll have no problems.
  2. The add and remove methods must be public and named void add<eventSetName>Listener(<listenerType>) and void remove<eventSetName>Listener(<listenerType>) in in class eventSourceClass, where <eventSetName> will have its first letter capitalized. Standard exception rules (see class description) apply.
Parameters:
eventSourceClass - the class containing the add/remove listener methods.
eventSetName - the programmatic name of the event set, generally starting with a lowercase letter (i.e. fooManChu instead of FooManChu). This will be used to generate the name of the event object as well as the names of the add and remove methods.
listenerType - the class containing the event firing method.
listenerMethodName - the name of the event firing method.
Throws:
IntrospectionException - if listenerType is not an EventListener, or if methods are not found or are invalid.

EventSetDescriptor

public EventSetDescriptor(Class eventSourceClass,
                          String eventSetName,
                          Class listenerType,
                          String[] listenerMethodNames,
                          String addListenerMethodName,
                          String removeListenerMethodName)
            throws IntrospectionException
Create a new EventSetDescriptor. This form of the constructor allows you to specify the names of the methods and adds no new constraints on top of the rules already described at the top of the class.

Parameters:
eventSourceClass - the class containing the add and remove listener methods.
eventSetName - the programmatic name of the event set, generally starting with a lowercase letter (i.e. fooManChu instead of FooManChu).
listenerType - the class containing the event firing methods.
listenerMethodNames - the names of the even firing methods.
addListenerMethodName - the name of the add listener method.
removeListenerMethodName - the name of the remove listener method.
Throws:
IntrospectionException - if listenerType is not an EventListener or if methods are not found or are invalid.

EventSetDescriptor

public EventSetDescriptor(String eventSetName,
                          Class listenerType,
                          MethodDescriptor[] listenerMethodDescriptors,
                          Method addListenerMethod,
                          Method removeListenerMethod)
            throws IntrospectionException
Create a new EventSetDescriptor. This form of constructor allows you to explicitly say which methods do what, and no reflection is done by the EventSetDescriptor. The methods are, however, checked to ensure that they follow the rules set forth at the top of the class.
Parameters:
eventSetName - the programmatic name of the event set, generally starting with a lowercase letter (i.e. fooManChu instead of FooManChu).
listenerType - the class containing the listenerMethods.
listenerMethodDescriptors - the event firing methods.
addListenerMethod - the add listener method.
removeListenerMethod - the remove listener method.
Throws:
IntrospectionException - if the listenerType is not an EventListener, or any of the methods are invalid.

EventSetDescriptor

public EventSetDescriptor(String eventSetName,
                          Class listenerType,
                          Method[] listenerMethods,
                          Method addListenerMethod,
                          Method removeListenerMethod)
            throws IntrospectionException
Create a new EventSetDescriptor. This form of constructor allows you to explicitly say which methods do what, and no reflection is done by the EventSetDescriptor. The methods are, however, checked to ensure that they follow the rules set forth at the top of the class.
Parameters:
eventSetName - the programmatic name of the event set, generally starting with a lowercase letter (i.e. fooManChu instead of FooManChu).
listenerType - the class containing the listenerMethods.
listenerMethods - the event firing methods.
addListenerMethod - the add listener method.
removeListenerMethod - the remove listener method.
Throws:
IntrospectionException - if the listenerType is not an EventListener, or any of the methods are invalid.

Method Details

getAddListenerMethod

public Method getAddListenerMethod()
Get the add listener method. *

getListenerMethodDescriptors

public MethodDescriptor[] getListenerMethodDescriptors()
Get the event firing methods as MethodDescriptors. *

getListenerMethods

public Method[] getListenerMethods()
Get the event firing methods. *

getListenerType

public Class getListenerType()
Get the class that contains the event firing methods. *

getRemoveListenerMethod

public Method getRemoveListenerMethod()
Get the remove listener method. *

isInDefaultEventSet

public boolean isInDefaultEventSet()
Get whether or not this is in the default event set. (Defaults to true.)*

isUnicast

public boolean isUnicast()
Get whether or not multiple listeners may be added. (Defaults to false.) *

setInDefaultEventSet

public void setInDefaultEventSet(boolean inDefaultEventSet)
Set whether or not this is in the default event set.
Parameters:
inDefaultEventSet - whether this is in the default event set.

setUnicast

public void setUnicast(boolean unicast)
Set whether or not multiple listeners may be added.
Parameters:
unicast - whether or not multiple listeners may be added.

java.beans.EventSetDescriptor Copyright (C) 1998 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath 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 for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.