| /* java.beans.beancontext.BeanContextServices |
| Copyright (C) 1999 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., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 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. */ |
| |
| |
| package java.beans.beancontext; |
| |
| import java.util.Iterator; |
| import java.util.TooManyListenersException; |
| |
| /** |
| * Allows a <code>BeanContext</code> to provide services to its children. |
| * |
| * @specnote it is unclear whether a <code>BeanContextServices</code> |
| * should delegate unhandled requests to parents. I assume so. |
| * @author John Keiser |
| * @since 1.2 |
| */ |
| |
| public interface BeanContextServices |
| extends BeanContext, BeanContextServicesListener |
| { |
| /** |
| * Register a service to make it available to others. |
| * This class may refuse to add the service based on whatever |
| * information it can gather, including whether the service |
| * provider is trusted. |
| * |
| * @param serviceClass the service class. |
| * @param provider the factory that will actually provide the service. |
| * @return whether the service was added or not. |
| */ |
| boolean addService (Class serviceClass, |
| BeanContextServiceProvider provider); |
| |
| /** |
| * Make it so that no one else can use this service. |
| * <P> |
| * |
| * If <code>revokeNow</code> is <code>false</code>, the only |
| * effect of this method is to make all subsequent calls to |
| * <code>getService()</code> on this service class fail. |
| * <P> |
| * |
| * If it is <code>true</code>, a message is also sent out to all |
| * listeners on the service and all references to it are released. |
| * |
| * @param serviceClass the service class to revoke. |
| * @param provider the service provider providing the service class. |
| * @param revokeNow whether to release all current references to |
| * the service. |
| */ |
| void revokeService (Class serviceClass, |
| BeanContextServiceProvider provider, |
| boolean revokeNow); |
| |
| /** |
| * Release your copy of this service. |
| * <P> |
| * |
| * If all copies of the service's class have been relinquished by |
| * the requestor, the <code>BeanContextServiceRevokedListener</code> |
| * previously registered by <code>getService()</code> will be |
| * unregistered. |
| * |
| * @param requestorChild the original <code>BeanContextChild</code> |
| * requesting the service. |
| * @param requestor the original requestor of the service. |
| * @param service the service to relinquish |
| * @see #getService(java.beans.beancontext.BeanContextChild,java.lang.Object,java.lang.Class,java.lang.Object,java.beans.beancontext.BeanContextServiceRevokedListener) |
| */ |
| void releaseService (BeanContextChild requestorChild, Object requestor, |
| Object service); |
| |
| /** |
| * Get a service from this <code>BeanContextServices</code>. |
| * <P> |
| * |
| * The specified listener will be registered to receive a |
| * revocation notice for the specified serviceClass. One |
| * notification per service class per requestor object will be |
| * sent. |
| * <P> |
| * |
| * The listener will be unregistered when all services that were |
| * obtained by that requestor for that service class are released. |
| * <P> |
| * |
| * If the requested service class is not available, or if this |
| * <code>BeanContextServices</code> object chooses not honor the |
| * request because the service class has been revoked or for some |
| * other reason, then this method will return <code>null</code>. |
| * <P> |
| * |
| * This method may throw unchecked exceptions, so watch out. |
| * |
| * @specnote it is not specified what happens when two subsequent |
| * calls are made to <code>getService()</code> with the |
| * same requestor object and service class but different |
| * listeners. Which listener is to be notified? |
| * |
| * @param requestorChild the <code>BeanContextChild</code> |
| * associated with the requestor. Typically this will be |
| * the same as the requestor itself, but since any |
| * <code>Object</code>, even one outside the hierarchy, may |
| * make a request, this parameter is necessary. Only weak |
| * references to this will be retained, and it will never |
| * be changed, only queried in a read-only manner. |
| * @param requestor the actual requestor of the service. Only |
| * weak references to this will be retained, and it will |
| * never be changed, only queried in a read-only manner. |
| * @param serviceClass the <code>Class</code> of the service being |
| * requested. |
| * @param serviceSelector a parameter to customize the service |
| * returned with. |
| * @param listener a listener that will be notified if the service |
| * being requested is revoked. |
| * @return an instance of <code>serviceClass</code> (such that |
| * <code>instanceof</code> serviceClass is true), or |
| * <code>null</code>. |
| */ |
| Object getService (BeanContextChild requestorChild, Object requestor, |
| Class serviceClass, Object serviceSelector, |
| BeanContextServiceRevokedListener listener) |
| throws TooManyListenersException; |
| |
| /** |
| * Get a list of all service classes supported. |
| * <P> |
| * |
| * This method must synchronize on |
| * <code>BeanContext.globalHierarchyLock</code>. |
| * |
| * @return a list of all service classes supported. |
| * @see java.beans.beancontext.BeanContext#globalHierarchyLock |
| */ |
| Iterator getCurrentServiceClasses (); |
| |
| /** |
| * Get a list of valid service selectors for the specified service class. |
| * <P> |
| * |
| * If the specified service class does not have a finite number of |
| * valid service selectors, it should return <code>null</code>. |
| * If it takes a general <code>Integer</code> parameter, for |
| * example, you may as well return <code>null</code> or the poor |
| * soul who called this method will be iterating all day. |
| * <P> |
| * |
| * If it has no valid service selectors, it should still return an empty |
| * <code>Iterator</code>. |
| * |
| * @param serviceClass the service class to get selectors for. |
| * @return a list of valid service selectors for the service |
| * class, or <code>null</code>. |
| */ |
| Iterator getCurrentServiceSelectors (Class serviceClass); |
| |
| /** |
| * Tell whether the specified service class is available. |
| * Iff getService() could return a non-null value for the |
| * specified service, this method will return <code>true</code>. |
| * |
| * @param serviceClass the service class to check on. |
| * @return whether the specified service class is available. |
| */ |
| boolean hasService (Class serviceClass); |
| |
| /** |
| * Add a listener on all adds and removes of services. |
| * @param listener the listener to add. |
| */ |
| void addBeanContextServicesListener (BeanContextServicesListener listener); |
| |
| /** |
| * Remove a listener on all adds and removes of services. |
| * @specnote it is not certain whether this should remove this |
| * listener if it was specified in |
| * <code>getService()</code>. |
| * @param listener the listener to add. |
| */ |
| void removeBeanContextServicesListener (BeanContextServicesListener listener); |
| } |