|
1
23
24 package org.apache.slide.event;
25
26 import org.apache.slide.util.conf.Configurable;
27 import org.apache.slide.util.conf.Configuration;
28 import org.apache.slide.util.conf.ConfigurationException;
29
30 import java.lang.reflect.Method  ;
31 import java.lang.reflect.Field ;
32 import java.util.*;
33
34
39 public class EventDispatcher implements Configurable {
40 private static EventDispatcher eventDispatcher = new EventDispatcher();
41
42 private List eventListeners = new ArrayList();
43
44 private EventDispatcher() {
45 }
46
47 public static EventDispatcher getInstance() {
48 return eventDispatcher;
49 }
50
51 public void addEventListener(EventListener listener) {
52 eventListeners.add(listener);
53 }
54
55 public void fireVetoableEvent(VetoableEventMethod eventMethod, EventObject event) throws VetoException {
56 for (Iterator i = eventListeners.iterator(); i.hasNext(); ) {
57 EventListener listener = (EventListener)i.next();
58 if ( listener instanceof GlobalListener ) {
59 ((GlobalListener)listener).vetoableEventFired(eventMethod, event);
60 } else {
61 eventMethod.fireVetaoableEvent(listener, event);
62 }
63 }
64 }
65
66 public void fireEvent(EventMethod eventMethod, EventObject event) {
67 for (Iterator i = eventListeners.iterator(); i.hasNext(); ) {
68 EventListener listener = (EventListener)i.next();
69 if ( listener instanceof GlobalListener ) {
70 ((GlobalListener)listener).eventFired(eventMethod, event);
71 } else {
72 eventMethod.fireEvent(listener, event);
73 }
74 }
75 }
76
77 public void configure(Configuration config) throws ConfigurationException {
78 Enumeration listenerConfigs = config.getConfigurations("listener");
79 while (listenerConfigs.hasMoreElements()) {
80 Configuration listenerConfig = (Configuration)listenerConfigs.nextElement();
81 String classname = listenerConfig.getAttribute("classname");
82 try {
83 Class listenerClass = Class.forName(classname);
84 EventListener eventListener = null;
85 try {
86 Method getInstanceMethod = listenerClass.getMethod("getInstance", new Class [0]);
87 eventListener = (EventListener)getInstanceMethod.invoke(null, null);
88 } catch ( NoSuchMethodException e) {
89 eventListener = (EventListener)listenerClass.newInstance();
90 }
91 if ( eventListener instanceof Configurable ) {
92 Configuration conf = null;
93 try {
94 conf = listenerConfig.getConfiguration("configuration");
95 } catch (ConfigurationException e) {
96 }
98 if (conf != null) {
99 ((Configurable)eventListener).configure(conf);
100 }
101 }
102 addEventListener(eventListener);
103 } catch (ClassCastException e) {
104 throw new ConfigurationException("Event listener '"+classname+"' is not of type EventListener", config);
105 } catch (Exception e) {
106 throw new ConfigurationException("Event listener '"+classname+"' could not be loaded", config);
107 }
108 }
109 Enumeration enableConfigs = config.getConfigurations("event");
110 while (enableConfigs.hasMoreElements()) {
111 Configuration enableConfig = (Configuration)enableConfigs.nextElement();
112 String classname = enableConfig.getAttribute("classname");
113 String method = enableConfig.getAttribute("method", null);
114 boolean enable = enableConfig.getAttributeAsBoolean("enable", true);
115 try {
116 Class eventClass = Class.forName(classname);
117 Field methodsField = eventClass.getField("methods");
118 AbstractEventMethod[] methods = (AbstractEventMethod [])methodsField.get(null);
119 for ( int i = 0; i < methods.length; i++ ) {
120 if ( method == null || methods[i].getName().equals(method) ) {
121 methods[i].setEnabled(enable);
122 }
123 }
124 } catch (NoSuchFieldException e) {
125 throw new ConfigurationException("Event '"+classname+"' does not provide the required static member 'methods'", config);
126 } catch (Exception e) {
127 throw new ConfigurationException("Event '"+classname+"' could not be loaded", config);
128 }
129 }
130 }
131 } |
Popular Tags |
Java API By Example, From Geeks To Geeks.