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Java > Open Source Codes > com > go > trove > util > plugin > PluginContext


1 /* ====================================================================
2  * Trove - Copyright (c) 1999-2001 Walt Disney Internet Group
3  * ====================================================================
4  * The Tea Software License, Version 1.1
5  *
6  * Copyright (c) 2000 Walt Disney Internet Group. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  * notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  * notice, this list of conditions and the following disclaimer in
17  * the documentation and/or other materials provided with the
18  * distribution.
19  *
20  * 3. The end-user documentation included with the redistribution,
21  * if any, must include the following acknowledgment:
22  * "This product includes software developed by the
23  * Walt Disney Internet Group (http://opensource.go.com/)."
24  * Alternately, this acknowledgment may appear in the software itself,
25  * if and wherever such third-party acknowledgments normally appear.
26  *
27  * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must
28  * not be used to endorse or promote products derived from this
29  * software without prior written permission. For written
30  * permission, please contact opensource@dig.com.
31  *
32  * 5. Products derived from this software may not be called "Tea",
33  * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet",
34  * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior
35  * written permission of the Walt Disney Internet Group.
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37  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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39  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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47  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
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50  * For more information about Tea, please see http://opensource.go.com/.
51  */
52 package com.go.trove.util.plugin;
53
54 import com.go.trove.util.PropertyMap;
55
56 import java.util.ArrayList JavaDoc;
57 import java.util.HashMap JavaDoc;
58 import java.util.List JavaDoc;
59 import java.util.Map JavaDoc;
60
61 /**
62  * Plugin can reference other Plugins through the PluginContext. If a Plugin is
63  * not immediately available the Plugin can register itself as a listener with
64  * the PluginContext so as to be notified when new Plugins are added to the
65  * PluginContext. When Plugins are fully initialized and want to make
66  * themselves available to other Plugins they should add themselves to the
67  * PluginContext.
68  *
69  * @author Scott Jappinen
70  * @version <!--$$Revision:--> 1 <!-- $-->-<!--$$JustDate:--> 01/03/23 <!-- $-->
71  */
72 public class PluginContext {
73     
74     private List JavaDoc mPluginListeners;
75     private Map mPluginMap;
76     
77     public PluginContext() {
78         mPluginListeners = new ArrayList JavaDoc();
79         mPluginMap = new HashMap JavaDoc(7);
80     }
81    
82     /**
83      * Adds a PluginListener to the PluginContext. Plugins or anything
84      * else that want to listen to PluginEvents should add themselves
85      * to the PluginContext through this method.
86      *
87      * @param listener the PluginListener to be added.
88      */
89     public void addPluginListener(PluginListener listener) {
90         if (!mPluginListeners.contains(listener)) {
91             mPluginListeners.add(listener);
92         }
93     }
94     
95     /**
96      * Adds a Plugin to the PluginContext. Plugins that want to make
97      * themselves available to other Plugins should add themselves
98      * to the PluginContext through this method. All PluginListeners
99      * will be notified of the new addition.
100      *
101      * @param plugin the Plugin to be added.
102      */
103     public void addPlugin(Plugin plugin) {
104         if (!mPluginMap.containsKey(plugin.getName())) {
105             mPluginMap.put(plugin.getName(), plugin);
106             PluginEvent event = new PluginEvent(this, plugin);
107             firePluginAddedEvent(event);
108         }
109     }
110
111     /**
112      * Returns a Plugin by name.
113      *
114      * @param name the name of the Plugin.
115      * @return Plugin the Plugin object.
116      */
117     public Plugin getPlugin(String JavaDoc name) {
118         return (Plugin) mPluginMap.get(name);
119     }
120     
121     /**
122      * Returns a Map of all of the Plugins.
123      *
124      * @return Map the map of Plugins.
125      */
126     public Map getPlugins() {
127         return new HashMap JavaDoc(mPluginMap);
128     }
129     
130     /* Notifies all PluginListeners of a Plugin being added to this class.
131      */
132     protected void firePluginAddedEvent(PluginEvent event) {
133         PluginListener[] listeners = new PluginListener[mPluginListeners.size()];
134         listeners = (PluginListener[]) mPluginListeners.toArray(listeners);
135         for (int i=0; i < listeners.length; i++) {
136             listeners[i].pluginAdded(event);
137         }
138     }
139 }
140
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