1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
|
/*
* Copyright 2000-2016 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.event;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.EventObject;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Objects;
import com.vaadin.server.ErrorEvent;
import com.vaadin.server.ErrorHandler;
import com.vaadin.shared.Registration;
import com.vaadin.shared.communication.SharedState;
import com.vaadin.shared.ui.ComponentStateUtil;
/**
* <code>EventRouter</code> class implementing the inheritable event listening
* model. For more information on the event model see the
* {@link com.vaadin.event package documentation}.
*
* @author Vaadin Ltd.
* @since 3.0
*/
@SuppressWarnings("serial")
public class EventRouter implements MethodEventSource {
/**
* List of registered listeners.
*/
private LinkedHashSet<ListenerMethod> listenerList = null;
/*
* Registers a new listener with the specified activation method to listen
* events generated by this component. Don't add a JavaDoc comment here, we
* use the default documentation from implemented interface.
*/
@Override
public Registration addListener(Class<?> eventType, Object object,
Method method) {
Objects.requireNonNull(object, "Listener must not be null.");
if (listenerList == null) {
listenerList = new LinkedHashSet<>();
}
ListenerMethod listenerMethod = new ListenerMethod(eventType, object,
method);
listenerList.add(listenerMethod);
return () -> listenerList.remove(listenerMethod);
}
/**
* Registers a new event listener with the specified activation method to
* listen events generated by this component. If the activation method does
* not have any arguments the event object will not be passed to it when
* it's called.
*
* <p>
* This method additionally informs the event-api to stop routing events
* with the given {@code eventIdentifier} to the components handleEvent
* function call.
* </p>
*
* <p>
* The only way to remove the listener is to use the returned
* {@link Registration}. The other methods, e.g.
* {@link #removeAllListeners()} do not do that.
* </p>
*
* <p>
* For more information on the inheritable event mechanism see the
* {@link com.vaadin.event com.vaadin.event package documentation}.
* </p>
*
* @param eventType
* the type of the listened event. Events of this type or its
* subclasses activate the listener.
* @param target
* the object instance who owns the activation method.
* @param method
* the activation method.
* @param eventIdentifier
* the identifier of the event to listen for
* @param state
* The component State
* @return a registration object for removing the listener
* @throws IllegalArgumentException
* unless {@code method} has exactly one match in {@code target}
* @throws NullPointerException
* if {@code target} is {@code null}
* @since 8.2
*/
public Registration addListener(Class<?> eventType, Object target,
Method method, String eventIdentifier, SharedState state) {
Objects.requireNonNull(target, "Listener must not be null.");
if (listenerList == null) {
listenerList = new LinkedHashSet<>();
}
ListenerMethod listenerMethod = new ListenerMethod(eventType, target,
method);
listenerList.add(listenerMethod);
Registration registration = ComponentStateUtil
.addRegisteredEventListener(state, eventIdentifier);
return () -> {
listenerList.remove(listenerMethod);
if (!hasListeners(eventType)) {
registration.remove();
}
};
}
/*
* Registers a new listener with the specified named activation method to
* listen events generated by this component. Don't add a JavaDoc comment
* here, we use the default documentation from implemented interface.
*/
@Override
public Registration addListener(Class<?> eventType, Object object,
String methodName) {
Objects.requireNonNull(object, "Listener must not be null.");
if (listenerList == null) {
listenerList = new LinkedHashSet<>();
}
ListenerMethod listenerMethod = new ListenerMethod(eventType, object,
methodName);
listenerList.add(listenerMethod);
return () -> listenerList.remove(listenerMethod);
}
/*
* Removes all registered listeners matching the given parameters. Don't add
* a JavaDoc comment here, we use the default documentation from implemented
* interface.
*/
@Override
public void removeListener(Class<?> eventType, Object target) {
if (listenerList != null) {
final Iterator<ListenerMethod> i = listenerList.iterator();
while (i.hasNext()) {
final ListenerMethod lm = i.next();
if (lm.matches(eventType, target)) {
i.remove();
return;
}
}
}
}
/*
* Removes the event listener methods matching the given given parameters.
* Don't add a JavaDoc comment here, we use the default documentation from
* implemented interface.
*/
@Override
public void removeListener(Class<?> eventType, Object target,
Method method) {
if (listenerList != null) {
final Iterator<ListenerMethod> i = listenerList.iterator();
while (i.hasNext()) {
final ListenerMethod lm = i.next();
if (lm.matches(eventType, target, method)) {
i.remove();
return;
}
}
}
}
/*
* Removes the event listener method matching the given given parameters.
* Don't add a JavaDoc comment here, we use the default documentation from
* implemented interface.
*/
@Override
public void removeListener(Class<?> eventType, Object target,
String methodName) {
// Find the correct method
final Method[] methods = target.getClass().getMethods();
Method method = null;
for (Method m : methods) {
if (m.getName().equals(methodName)) {
method = m;
break;
}
}
if (method == null) {
throw new IllegalArgumentException();
}
// Remove the listeners
if (listenerList != null) {
final Iterator<ListenerMethod> i = listenerList.iterator();
while (i.hasNext()) {
final ListenerMethod lm = i.next();
if (lm.matches(eventType, target, method)) {
i.remove();
return;
}
}
}
}
/**
* Removes all listeners from event router.
*/
public void removeAllListeners() {
listenerList = null;
}
/**
* Sends an event to all registered listeners. The listeners will decide if
* the activation method should be called or not.
*
* @param event
* the Event to be sent to all listeners.
*/
public void fireEvent(EventObject event) {
fireEvent(event, null);
}
/**
* Sends an event to all registered listeners. The listeners will decide if
* the activation method should be called or not.
* <p>
* If an error handler is set, the processing of other listeners will
* continue after the error handler method call unless the error handler
* itself throws an exception.
*
* @param event
* the Event to be sent to all listeners.
* @param errorHandler
* error handler to use to handle any exceptions thrown by
* listeners or null to let the exception propagate to the
* caller, preventing further listener calls
*/
public void fireEvent(EventObject event, ErrorHandler errorHandler) {
// It is not necessary to send any events if there are no listeners
if (listenerList != null) {
// Make a copy of the listener list to allow listeners to be added
// inside listener methods. Fixes #3605.
// Send the event to all listeners. The listeners themselves
// will filter out unwanted events.
for (Object l : listenerList.toArray()) {
ListenerMethod listenerMethod = (ListenerMethod) l;
if (null != errorHandler) {
try {
listenerMethod.receiveEvent(event);
} catch (Exception e) {
errorHandler.error(new ErrorEvent(e));
}
} else {
listenerMethod.receiveEvent(event);
}
}
}
}
/**
* Checks if the given Event type is listened by a listener registered to
* this router.
*
* @param eventType
* the event type to be checked
* @return true if a listener is registered for the given event type
*/
public boolean hasListeners(Class<?> eventType) {
if (listenerList != null) {
for (ListenerMethod lm : listenerList) {
if (lm.isType(eventType)) {
return true;
}
}
}
return false;
}
/**
* Returns all listeners that match or extend the given event type.
*
* @param eventType
* The type of event to return listeners for.
* @return A collection with all registered listeners. Empty if no listeners
* are found.
*/
public Collection<?> getListeners(Class<?> eventType) {
List<Object> listeners = new ArrayList<>();
if (listenerList != null) {
for (ListenerMethod lm : listenerList) {
if (lm.isOrExtendsType(eventType)) {
listeners.add(lm.getTarget());
}
}
}
return listeners;
}
}
|