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      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
     29     add(Handler h, int what, Object obj)
     30     {
     31         add(new Registrant(h, what, obj));
     32     }
     33 
     34     public synchronized void
     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
     43     add(Registrant r)
     44     {
     45         removeCleared();
     46         registrants.add(r);
     47     }
     48 
     49     public synchronized void
     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
     62     size()
     63     {
     64         return registrants.size();
     65     }
     66 
     67     public synchronized Object
     68     get(int index)
     69     {
     70         return registrants.get(index);
     71     }
     72 
     73     private synchronized void
     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
     83     notifyRegistrants()
     84     {
     85         internalNotifyRegistrants(null, null);
     86     }
     87 
     88     public /*synchronized*/ void
     89     notifyException(Throwable exception)
     90     {
     91         internalNotifyRegistrants (null, exception);
     92     }
     93 
     94     public /*synchronized*/ void
     95     notifyResult(Object result)
     96     {
     97         internalNotifyRegistrants (result, null);
     98     }
     99 
    100 
    101     public /*synchronized*/ void
    102     notifyRegistrants(AsyncResult ar)
    103     {
    104         internalNotifyRegistrants(ar.result, ar.exception);
    105     }
    106 
    107     public synchronized void
    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