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.annotation.UnsupportedAppUsage; 20 import android.os.Handler; 21 import android.os.Message; 22 23 import java.lang.ref.WeakReference; 24 25 /** @hide */ 26 public class Registrant 27 { 28 @UnsupportedAppUsage 29 public Registrant(Handler h, int what, Object obj)30 Registrant(Handler h, int what, Object obj) 31 { 32 refH = new WeakReference(h); 33 this.what = what; 34 userObj = obj; 35 } 36 37 @UnsupportedAppUsage 38 public void clear()39 clear() 40 { 41 refH = null; 42 userObj = null; 43 } 44 45 @UnsupportedAppUsage 46 public void notifyRegistrant()47 notifyRegistrant() 48 { 49 internalNotifyRegistrant (null, null); 50 } 51 52 @UnsupportedAppUsage 53 public void notifyResult(Object result)54 notifyResult(Object result) 55 { 56 internalNotifyRegistrant (result, null); 57 } 58 59 public void notifyException(Throwable exception)60 notifyException(Throwable exception) 61 { 62 internalNotifyRegistrant (null, exception); 63 } 64 65 /** 66 * This makes a copy of @param ar 67 */ 68 @UnsupportedAppUsage 69 public void notifyRegistrant(AsyncResult ar)70 notifyRegistrant(AsyncResult ar) 71 { 72 internalNotifyRegistrant (ar.result, ar.exception); 73 } 74 75 /*package*/ void internalNotifyRegistrant(Object result, Throwable exception)76 internalNotifyRegistrant (Object result, Throwable exception) 77 { 78 Handler h = getHandler(); 79 80 if (h == null) { 81 clear(); 82 } else { 83 Message msg = Message.obtain(); 84 85 msg.what = what; 86 87 msg.obj = new AsyncResult(userObj, result, exception); 88 89 h.sendMessage(msg); 90 } 91 } 92 93 /** 94 * NOTE: May return null if weak reference has been collected 95 */ 96 97 @UnsupportedAppUsage 98 public Message messageForRegistrant()99 messageForRegistrant() 100 { 101 Handler h = getHandler(); 102 103 if (h == null) { 104 clear(); 105 106 return null; 107 } else { 108 Message msg = h.obtainMessage(); 109 110 msg.what = what; 111 msg.obj = userObj; 112 113 return msg; 114 } 115 } 116 117 public Handler getHandler()118 getHandler() 119 { 120 if (refH == null) 121 return null; 122 123 return (Handler) refH.get(); 124 } 125 126 WeakReference refH; 127 int what; 128 Object userObj; 129 } 130 131