1 /*
2  * Copyright (C) 2006 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.os;
18 
19 import android.os.Handler;
20 
21 import java.util.ArrayList;
22 
23 /** @hide */
24 public class RegistrantList
25 {
26     ArrayList   registrants = new ArrayList();      // of Registrant
27 
28     public synchronized void
add(Handler h, int what, Object obj)29     add(Handler h, int what, Object obj)
30     {
31         add(new Registrant(h, what, obj));
32     }
33 
34     public synchronized void
addUnique(Handler h, int what, Object obj)35     addUnique(Handler h, int what, Object obj)
36     {
37         // if the handler is already in the registrant list, remove it
38         remove(h);
39         add(new Registrant(h, what, obj));
40     }
41 
42     public synchronized void
add(Registrant r)43     add(Registrant r)
44     {
45         removeCleared();
46         registrants.add(r);
47     }
48 
49     public synchronized void
removeCleared()50     removeCleared()
51     {
52         for (int i = registrants.size() - 1; i >= 0 ; i--) {
53             Registrant  r = (Registrant) registrants.get(i);
54 
55             if (r.refH == null) {
56                 registrants.remove(i);
57             }
58         }
59     }
60 
61     public synchronized int
size()62     size()
63     {
64         return registrants.size();
65     }
66 
67     public synchronized Object
get(int index)68     get(int index)
69     {
70         return registrants.get(index);
71     }
72 
73     private synchronized void
internalNotifyRegistrants(Object result, Throwable exception)74     internalNotifyRegistrants (Object result, Throwable exception)
75     {
76        for (int i = 0, s = registrants.size(); i < s ; i++) {
77             Registrant  r = (Registrant) registrants.get(i);
78             r.internalNotifyRegistrant(result, exception);
79        }
80     }
81 
82     public /*synchronized*/ void
notifyRegistrants()83     notifyRegistrants()
84     {
85         internalNotifyRegistrants(null, null);
86     }
87 
88     public /*synchronized*/ void
notifyException(Throwable exception)89     notifyException(Throwable exception)
90     {
91         internalNotifyRegistrants (null, exception);
92     }
93 
94     public /*synchronized*/ void
notifyResult(Object result)95     notifyResult(Object result)
96     {
97         internalNotifyRegistrants (result, null);
98     }
99 
100 
101     public /*synchronized*/ void
notifyRegistrants(AsyncResult ar)102     notifyRegistrants(AsyncResult ar)
103     {
104         internalNotifyRegistrants(ar.result, ar.exception);
105     }
106 
107     public synchronized void
remove(Handler h)108     remove(Handler h)
109     {
110         for (int i = 0, s = registrants.size() ; i < s ; i++) {
111             Registrant  r = (Registrant) registrants.get(i);
112             Handler     rh;
113 
114             rh = r.getHandler();
115 
116             /* Clean up both the requested registrant and
117              * any now-collected registrants
118              */
119             if (rh == null || rh == h) {
120                 r.clear();
121             }
122         }
123 
124         removeCleared();
125     }
126 }
127