mirror of
git://gcc.gnu.org/git/gcc.git
synced 2024-12-24 14:19:33 +08:00
273 lines
10 KiB
Java
273 lines
10 KiB
Java
/* java.beans.beancontext.BeanContext
|
|
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.Collection;
|
|
import java.beans.Visibility;
|
|
import java.beans.DesignMode;
|
|
import java.net.URL;
|
|
import java.io.InputStream;
|
|
import java.io.IOException;
|
|
|
|
/**
|
|
* Acts as a container for sub-beans and as a sub-bean,
|
|
* so that an entire hierarchy of beans can be made up of
|
|
* <code>BeanContext</code>s.
|
|
* <P>
|
|
*
|
|
* Since I can't sprinkle the <code>Collections</code> interface
|
|
* documentation with special information for <code>BeanContext</code>
|
|
* implementors, I'll have to document special requirements for
|
|
* implementors of those functions here.
|
|
* <P>
|
|
*
|
|
* <code><strong>add()</strong></code> or <code>addAll()</code>:
|
|
* <br>
|
|
* <OL>
|
|
* <LI>
|
|
* May add any <code>Object</code> into the hierarchy as well as a
|
|
* <code>BeanContextChild</code>, <code>BeanContext</code> or
|
|
* <code>BeanContextProxy</code> object.
|
|
* This way, any Bean can be in the hierarchy.
|
|
* </LI>
|
|
* <LI>
|
|
* Must synchronize on <code>BeanContext.globalHierarchyLock</code>.
|
|
* </LI>
|
|
* <LI>
|
|
* Don't add the <code>Object</code> if it's already there (only once
|
|
* per <code>BeanContext</code>).
|
|
* </LI>
|
|
* <LI>
|
|
* If it is a <code>BeanContextChild</code> implementor, call
|
|
* <code>setBeanContext()</code> on it. If it's a
|
|
* <code>BeanContextProxy</code> implementor, call
|
|
* <code>getBeanContextProxy().setBeanContext()</code> on it.
|
|
* If <code>setBeanContext()</code> vetoes the change, back out
|
|
* all changes so far and throw <code>IllegalStateException</code>.
|
|
* </LI>
|
|
* <LI>
|
|
* If it (or its proxy) implements <code>Visibility</code>, call
|
|
* <code>dontUseGui()</code> or <code>okToUseGui()</code> on it,
|
|
* depending on whether you (the <code>BeanContext</code>) feel like
|
|
* allowing it to use the GUI or not.
|
|
* </LI>
|
|
* <LI>
|
|
* If it implements <code>BeanContextChild</code> or
|
|
* <code>BeanContextProxy</code>, register yourself (the
|
|
* <code>BeanContext</code>) as both a
|
|
* <code>PropertyChangeListener</code> and
|
|
* <code>VetoableChangeListener</code> on the "beanContext"
|
|
* property (it may also add itself on any other properties it wishes
|
|
* to).
|
|
* </LI>
|
|
* <LI>
|
|
* If it is a listener or event source that you (the
|
|
* <code>BeanContext</code>) are interested in, you may register
|
|
* yourself to it or register it to you.
|
|
* </LI>
|
|
* <LI>
|
|
* Fire a <code>java.beans.beancontext.BeanContextMembershipEvent</code>
|
|
* before exiting. <code>addAll()</code> should wait until everything
|
|
* is done changing before firing the event (or events) so that if a
|
|
* failure occurs, the backing-out process can proceed without any
|
|
* events being fired at all.
|
|
* </LI>
|
|
* </OL>
|
|
* <P>
|
|
*
|
|
* <code><strong>remove()</strong></code> or <code>removeAll()</code>:
|
|
* <br>
|
|
* <OL>
|
|
* <LI>
|
|
* Must synchronize on <code>BeanContext.globalHierarchyLock</code>.
|
|
* </LI>
|
|
* <LI>
|
|
* If the specified <code>Object</code> is not a child of this
|
|
* <code>BeanContext</code>, just exit without performing any actions.
|
|
* </LI>
|
|
* <LI>
|
|
* Remove the <code>Object</code> from your collection of children.
|
|
* </LI>
|
|
* <LI>
|
|
* If it is a <code>BeanContextChild</code> implementor, call
|
|
* <code>setBeanContext(null)</code> on it. If it's a
|
|
* <code>BeanContextProxy</code> implementor, call
|
|
* <code>getBeanContextProxy().setBeanContext(null)</code> on it.
|
|
* If <code>setBeanContext()</code> vetoes the change, back out
|
|
* all changes so far and throw <code>IllegalStateException</code>.
|
|
* </LI>
|
|
* <LI>
|
|
* If you registered the <code>Object</code> to listen to you or
|
|
* registered yourself as a listener on the <code>Object</code> during
|
|
* <code>add()</code> or <code>addAll()</code>, undo the registration
|
|
* bycalling the appropriate <code>removeListener()</code> method.
|
|
* </LI>
|
|
* <LI>
|
|
* Fire a <code>java.beans.beancontext.BeanContextMembershipEvent</code>
|
|
* before exiting. <code>removeAll()</code> should wait until
|
|
* everything is done changing before firing the event (or events) so
|
|
* that if a failure occurs, the backing-out process can proceed
|
|
* without any events being fired at all.
|
|
* </LI>
|
|
* </OL>
|
|
* <P>
|
|
*
|
|
* <code>addAll()</code>, <code>removeAll()</code>,
|
|
* <code>retainAll()</code> and <code>clear()</code> do not need to be
|
|
* implemented, but may be if so desired.
|
|
* <P>
|
|
*
|
|
* Similarly, <code>Visibility</code> and <code>DesignMode</code> methods
|
|
* should propagate changed values to children that implement interfaces
|
|
* of the same name.
|
|
* <P>
|
|
*
|
|
* A hierarchy of beans is mainly useful so that different sets of beans
|
|
* can be established, each with their own set of resources.
|
|
*
|
|
* @author John Keiser
|
|
* @since JDK1.2
|
|
*/
|
|
|
|
public interface BeanContext
|
|
extends Collection, BeanContextChild, Visibility, DesignMode {
|
|
|
|
/**
|
|
* The global lock on changing any BeanContext hierarchy.
|
|
* It kinda sucks that there is only one lock, since there can be
|
|
* multiple hierarchies. Oh well, I didn't design, I just code.
|
|
* <P>
|
|
*
|
|
* Methods that must (or do) synchronize on the global lock:
|
|
* <BR>
|
|
* <UL>
|
|
* <LI>
|
|
* Implementors of <CODE>BeanContext.add()</CODE> and <code>addAll()</code>
|
|
* </LI>
|
|
* </UL>
|
|
* @fixme fill in the rest of the methods which use the global lock.
|
|
*/
|
|
public static final Object globalHierarchyLock = new Object();
|
|
|
|
/**
|
|
* Instantiate a Bean using this Bean's <code>ClassLoader</code>
|
|
* and this <code>BeanContext</code> as the parent.
|
|
* <P>
|
|
*
|
|
* This method exists mainly so that <code>BeanContext</code>
|
|
* implementations can perform extra actions on Beans that are
|
|
* created within them.
|
|
*
|
|
* @param beanName the name of the bean to instantiate
|
|
* @return the created Bean
|
|
*
|
|
* @see java.beans.Beans#instantiate(java.lang.ClassLoader,java.lang.String)
|
|
* @see java.beans.Beans#instantiate(java.lang.ClassLoader,java.lang.String,java.lang.BeanContext)
|
|
* @exception IOException if there is an I/O problem during
|
|
* instantiation.
|
|
* @exception ClassNotFoundException if a serialized Bean's class
|
|
* is not found.
|
|
*/
|
|
public Object instantiateChild(String beanName)
|
|
throws IOException,
|
|
ClassNotFoundException;
|
|
|
|
/**
|
|
* Get a resource. The <code>BeanContext</code> will typically
|
|
* call <code>ClassLoader.getResource()</code>, but may do it any
|
|
* way it wants to. This allows a <code>BeanContext</code> to
|
|
* have its own set of resources separate from the rest of the
|
|
* system.
|
|
* <P>
|
|
*
|
|
* Beans should call this method on their parent rather than the
|
|
* associated <code>ClassLoader</code> method.
|
|
* <P>
|
|
*
|
|
* I am assuming, but am not entirely sure, that if a
|
|
* <code>BeanContext</code> cannot find a resource, its
|
|
* responsibility is to call the <code>getResource</code> method
|
|
* of its parent <code>BeanContext</code>.
|
|
*
|
|
* @return a URL to the requested resource.
|
|
* @param resourceName the name of the resource requested.
|
|
* @param requestor a reference to the child requesting the resource.
|
|
* @see java.lang.ClassLoader#getResource(java.lang.String)
|
|
*/
|
|
public URL getResource(String resourceName, BeanContextChild requestor);
|
|
|
|
/**
|
|
* Get a resource as a stream. The <code>BeanContext</code> will
|
|
* typically call <code>ClassLoader.getResourceAsStream()</code>,
|
|
* but may do it any way it wants to. This allows a
|
|
* <code>BeanContext</code>'s children to have their own set of
|
|
* resources separate from the rest of the system.
|
|
* <P>
|
|
*
|
|
* Beans should call this method on their parent rather than the
|
|
* associated <code>ClassLoader</code> method.
|
|
* <P>
|
|
*
|
|
* I am assuming, but am not entirely sure, that if a
|
|
* <code>BeanContext</code> cannot find a resource, its
|
|
* responsibility is to call the <code>getResourceAsStream</code>
|
|
* method of its parent <code>BeanContext</code>.
|
|
*
|
|
* @return the requested resource as a stream.
|
|
* @param resourceName the name of the resource requested.
|
|
* @param requestor a reference to the child requesting the resource.
|
|
* @see java.lang.ClassLoader#getResourceAsStream(java.lang.String)
|
|
*/
|
|
public InputStream getResourceAsStream(String resourceName, BeanContextChild requestor);
|
|
|
|
/**
|
|
* Add a listener on changes to the membership of this
|
|
* <code>BeanContext</code> object.
|
|
* @param listener the listener to add.
|
|
*/
|
|
public void addBeanContextMembershipListener(BeanContextMembershipListener listener);
|
|
|
|
/**
|
|
* Remove a listener on changes to the membership of this
|
|
* <code>BeanContext</code> object.
|
|
* @param listener the listener to remove.
|
|
*/
|
|
public void removeBeanContextMembershipListener(BeanContextMembershipListener listener);
|
|
}
|