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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 import android.os.Message;
     21 
     22 import java.util.ArrayList;
     23 import java.util.HashMap;
     24 
     25 /** @hide */
     26 public class RegistrantList
     27 {
     28     ArrayList   registrants = new ArrayList();      // of Registrant
     29 
     30     public synchronized void
     31     add(Handler h, int what, Object obj)
     32     {
     33         add(new Registrant(h, what, obj));
     34     }
     35 
     36     public synchronized void
     37     addUnique(Handler h, int what, Object obj)
     38     {
     39         // if the handler is already in the registrant list, remove it
     40         remove(h);
     41         add(new Registrant(h, what, obj));
     42     }
     43 
     44     public synchronized void
     45     add(Registrant r)
     46     {
     47         removeCleared();
     48         registrants.add(r);
     49     }
     50 
     51     public synchronized void
     52     removeCleared()
     53     {
     54         for (int i = registrants.size() - 1; i >= 0 ; i--) {
     55             Registrant  r = (Registrant) registrants.get(i);
     56 
     57             if (r.refH == null) {
     58                 registrants.remove(i);
     59             }
     60         }
     61     }
     62 
     63     public synchronized int
     64     size()
     65     {
     66         return registrants.size();
     67     }
     68 
     69     public synchronized Object
     70     get(int index)
     71     {
     72         return registrants.get(index);
     73     }
     74 
     75     private synchronized void
     76     internalNotifyRegistrants (Object result, Throwable exception)
     77     {
     78        for (int i = 0, s = registrants.size(); i < s ; i++) {
     79             Registrant  r = (Registrant) registrants.get(i);
     80             r.internalNotifyRegistrant(result, exception);
     81        }
     82     }
     83 
     84     public /*synchronized*/ void
     85     notifyRegistrants()
     86     {
     87         internalNotifyRegistrants(null, null);
     88     }
     89 
     90     public /*synchronized*/ void
     91     notifyException(Throwable exception)
     92     {
     93         internalNotifyRegistrants (null, exception);
     94     }
     95 
     96     public /*synchronized*/ void
     97     notifyResult(Object result)
     98     {
     99         internalNotifyRegistrants (result, null);
    100     }
    101 
    102 
    103     public /*synchronized*/ void
    104     notifyRegistrants(AsyncResult ar)
    105     {
    106         internalNotifyRegistrants(ar.result, ar.exception);
    107     }
    108 
    109     public synchronized void
    110     remove(Handler h)
    111     {
    112         for (int i = 0, s = registrants.size() ; i < s ; i++) {
    113             Registrant  r = (Registrant) registrants.get(i);
    114             Handler     rh;
    115 
    116             rh = r.getHandler();
    117 
    118             /* Clean up both the requested registrant and
    119              * any now-collected registrants
    120              */
    121             if (rh == null || rh == h) {
    122                 r.clear();
    123             }
    124         }
    125 
    126         removeCleared();
    127     }
    128 }
    129