1 /*
2  * Copyright (C) 2013 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.support.v7.media;
18 
19 import android.content.Intent;
20 import android.os.Messenger;
21 
22 /**
23  * Defines the communication protocol for media route provider services.
24  * @hide
25  */
26 abstract class MediaRouteProviderProtocol {
27     /**
28      * The {@link Intent} that must be declared as handled by the service.
29      * Put this in your manifest.
30      */
31     public static final String SERVICE_INTERFACE =
32             "android.media.MediaRouteProviderService";
33 
34     /*
35      * Messages sent from the client to the service.
36      * DO NOT RENUMBER THESE!
37      */
38 
39     /** (client v1)
40      * Register client.
41      * - replyTo : client messenger
42      * - arg1    : request id
43      * - arg2    : client version
44      */
45     public static final int CLIENT_MSG_REGISTER = 1;
46 
47     /** (client v1)
48      * Unregister client.
49      * - replyTo : client messenger
50      * - arg1    : request id
51      */
52     public static final int CLIENT_MSG_UNREGISTER = 2;
53 
54     /** (client v1)
55      * Create route controller.
56      * - replyTo : client messenger
57      * - arg1    : request id
58      * - arg2    : route controller id
59      * - CLIENT_DATA_ROUTE_ID : route id string
60      */
61     public static final int CLIENT_MSG_CREATE_ROUTE_CONTROLLER = 3;
62 
63     /** (client v1)
64      * Release route controller.
65      * - replyTo : client messenger
66      * - arg1    : request id
67      * - arg2    : route controller id
68      */
69     public static final int CLIENT_MSG_RELEASE_ROUTE_CONTROLLER = 4;
70 
71     /** (client v1)
72      * Select route.
73      * - replyTo : client messenger
74      * - arg1    : request id
75      * - arg2    : route controller id
76      */
77     public static final int CLIENT_MSG_SELECT_ROUTE = 5;
78 
79     /** (client v1)
80      * Unselect route.
81      * - replyTo : client messenger
82      * - arg1    : request id
83      * - arg2    : route controller id
84      */
85     public static final int CLIENT_MSG_UNSELECT_ROUTE = 6;
86 
87     /** (client v1)
88      * Set route volume.
89      * - replyTo : client messenger
90      * - arg1    : request id
91      * - arg2    : route controller id
92      * - CLIENT_DATA_VOLUME : volume integer
93      */
94     public static final int CLIENT_MSG_SET_ROUTE_VOLUME = 7;
95 
96     /** (client v1)
97      * Update route volume.
98      * - replyTo : client messenger
99      * - arg1    : request id
100      * - arg2    : route controller id
101      * - CLIENT_DATA_VOLUME : volume delta integer
102      */
103     public static final int CLIENT_MSG_UPDATE_ROUTE_VOLUME = 8;
104 
105     /** (client v1)
106      * Route control request.
107      * - replyTo : client messenger
108      * - arg1    : request id
109      * - arg2    : route controller id
110      * - obj     : media control intent
111      */
112     public static final int CLIENT_MSG_ROUTE_CONTROL_REQUEST = 9;
113 
114     /** (client v1)
115      * Sets the discovery request.
116      * - replyTo : client messenger
117      * - arg1    : request id
118      * - obj     : discovery request bundle, or null if none
119      */
120     public static final int CLIENT_MSG_SET_DISCOVERY_REQUEST = 10;
121 
122     public static final String CLIENT_DATA_ROUTE_ID = "routeId";
123     public static final String CLIENT_DATA_VOLUME = "volume";
124     public static final String CLIENT_DATA_UNSELECT_REASON = "unselectReason";
125 
126     /*
127      * Messages sent from the service to the client.
128      * DO NOT RENUMBER THESE!
129      */
130 
131     /** (service v1)
132      * Generic failure sent in response to any unrecognized or malformed request.
133      * - arg1    : request id
134      */
135     public static final int SERVICE_MSG_GENERIC_FAILURE = 0;
136 
137     /** (service v1)
138      * Generic failure sent in response to a successful message.
139      * - arg1    : request id
140      */
141     public static final int SERVICE_MSG_GENERIC_SUCCESS = 1;
142 
143     /** (service v1)
144      * Registration succeeded.
145      * - arg1    : request id
146      * - arg2    : server version
147      * - obj     : route provider descriptor bundle, or null
148      */
149     public static final int SERVICE_MSG_REGISTERED = 2;
150 
151     /** (service v1)
152      * Route control request success result.
153      * - arg1    : request id
154      * - obj     : result data bundle, or null
155      */
156     public static final int SERVICE_MSG_CONTROL_REQUEST_SUCCEEDED = 3;
157 
158     /** (service v1)
159      * Route control request failure result.
160      * - arg1    : request id
161      * - obj     : result data bundle, or null
162      * - SERVICE_DATA_ERROR: error message
163      */
164     public static final int SERVICE_MSG_CONTROL_REQUEST_FAILED = 4;
165 
166     /** (service v1)
167      * Route provider descriptor changed.  (unsolicited event)
168      * - arg1    : reserved (0)
169      * - obj     : route provider descriptor bundle, or null
170      */
171     public static final int SERVICE_MSG_DESCRIPTOR_CHANGED = 5;
172 
173     public static final String SERVICE_DATA_ERROR = "error";
174 
175     /*
176      * Recognized client version numbers.  (Reserved for future use.)
177      * DO NOT RENUMBER THESE!
178      */
179 
180     public static final int CLIENT_VERSION_1 = 1;
181     public static final int CLIENT_VERSION_CURRENT = CLIENT_VERSION_1;
182 
183     /*
184      * Recognized server version numbers.  (Reserved for future use.)
185      * DO NOT RENUMBER THESE!
186      */
187 
188     public static final int SERVICE_VERSION_1 = 1;
189     public static final int SERVICE_VERSION_CURRENT = SERVICE_VERSION_1;
190 
191     /**
192      * Returns true if the messenger object is valid.
193      * <p>
194      * The messenger constructor and unparceling code does not check whether the
195      * provided IBinder is a valid IMessenger object.  As a result, it's possible
196      * for a peer to send an invalid IBinder that will result in crashes downstream.
197      * This method checks that the messenger is in a valid state.
198      * </p>
199      */
isValidRemoteMessenger(Messenger messenger)200     public static boolean isValidRemoteMessenger(Messenger messenger) {
201         try {
202             return messenger != null && messenger.getBinder() != null;
203         } catch (NullPointerException ex) {
204             // If the messenger was constructed with a binder interface other than
205             // IMessenger then the call to getBinder() will crash with an NPE.
206             return false;
207         }
208     }
209 }
210