summaryrefslogtreecommitdiffstats
path: root/server/src/com/vaadin/event/EventRouter.java
blob: 73bfa33881d1e7b96c8ecf6b1709b969368791e0 (plain)
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
/*
 * Copyright 2000-2013 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;

/**
 * <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 void addListener(Class<?> eventType, Object object, Method method) {
        if (listenerList == null) {
            listenerList = new LinkedHashSet<ListenerMethod>();
        }
        listenerList.add(new ListenerMethod(eventType, object, method));
    }

    /*
     * 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 void addListener(Class<?> eventType, Object object, String methodName) {
        if (listenerList == null) {
            listenerList = new LinkedHashSet<ListenerMethod>();
        }
        listenerList.add(new ListenerMethod(eventType, object, methodName));
    }

    /*
     * 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 paramaters.
     * 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 (int i = 0; i < methods.length; i++) {
            if (methods[i].getName().equals(methodName)) {
                method = methods[i];
            }
        }
        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) {
        // 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.
            final Object[] listeners = listenerList.toArray();
            for (int i = 0; i < listeners.length; i++) {
                ((ListenerMethod) listeners[i]).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<Object>();
        if (listenerList != null) {
            for (ListenerMethod lm : listenerList) {
                if (lm.isOrExtendsType(eventType)) {
                    listeners.add(lm.getTarget());
                }
            }
        }
        return listeners;
    }
}