1 /*
2  * Copyright (C) 2014 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.telephony;
18 
19 import android.content.ComponentName;
20 import android.content.Context;
21 import android.content.Intent;
22 import android.content.ServiceConnection;
23 import android.os.IBinder;
24 import android.service.carrier.CarrierMessagingService;
25 import android.service.carrier.ICarrierMessagingService;
26 
27 import com.android.internal.util.Preconditions;
28 
29 /**
30  * Provides basic structure for platform to connect to the carrier messaging service.
31  * <p>
32  * <code>
33  * CarrierMessagingServiceManager carrierMessagingServiceManager =
34  *     new CarrierMessagingServiceManagerImpl();
35  * if (carrierMessagingServiceManager.bindToCarrierMessagingService(context, carrierPackageName)) {
36  *   // wait for onServiceReady callback
37  * } else {
38  *   // Unable to bind: handle error.
39  * }
40  * </code>
41  * <p> Upon completion {@link #disposeConnection} should be called to unbind the
42  * CarrierMessagingService.
43  * @hide
44  */
45 public abstract class CarrierMessagingServiceManager {
46     // Populated by bindToCarrierMessagingService. bindToCarrierMessagingService must complete
47     // prior to calling disposeConnection so that mCarrierMessagingServiceConnection is initialized.
48     private volatile CarrierMessagingServiceConnection mCarrierMessagingServiceConnection;
49 
50     /**
51      * Binds to the carrier messaging service under package {@code carrierPackageName}. This method
52      * should be called exactly once.
53      *
54      * @param context the context
55      * @param carrierPackageName the carrier package name
56      * @return true upon successfully binding to a carrier messaging service, false otherwise
57      */
bindToCarrierMessagingService(Context context, String carrierPackageName)58     public boolean bindToCarrierMessagingService(Context context, String carrierPackageName) {
59         Preconditions.checkState(mCarrierMessagingServiceConnection == null);
60 
61         Intent intent = new Intent(CarrierMessagingService.SERVICE_INTERFACE);
62         intent.setPackage(carrierPackageName);
63         mCarrierMessagingServiceConnection = new CarrierMessagingServiceConnection();
64         return context.bindService(intent, mCarrierMessagingServiceConnection,
65                 Context.BIND_AUTO_CREATE);
66     }
67 
68     /**
69      * Unbinds the carrier messaging service. This method should be called exactly once.
70      *
71      * @param context the context
72      */
disposeConnection(Context context)73     public void disposeConnection(Context context) {
74         Preconditions.checkNotNull(mCarrierMessagingServiceConnection);
75         context.unbindService(mCarrierMessagingServiceConnection);
76         mCarrierMessagingServiceConnection = null;
77     }
78 
79     /**
80      * Implemented by subclasses to use the carrier messaging service once it is ready.
81      *
82      * @param carrierMessagingService the carrier messaing service interface
83      */
onServiceReady(ICarrierMessagingService carrierMessagingService)84     protected abstract void onServiceReady(ICarrierMessagingService carrierMessagingService);
85 
86     /**
87      * A basic {@link ServiceConnection}.
88      */
89     private final class CarrierMessagingServiceConnection implements ServiceConnection {
90         @Override
onServiceConnected(ComponentName name, IBinder service)91         public void onServiceConnected(ComponentName name, IBinder service) {
92             onServiceReady(ICarrierMessagingService.Stub.asInterface(service));
93         }
94 
95         @Override
onServiceDisconnected(ComponentName name)96         public void onServiceDisconnected(ComponentName name) {
97         }
98     }
99 }
100