1 /**
2  * Copyright (c) 2018, 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.ExternalVibration;
20 
21 /**
22  * The communication channel by which an external system that wants to control the system
23  * vibrator can notify the vibrator subsystem.
24  *
25  * Some vibrators can be driven via multiple paths (e.g. as an audio channel) in addition to
26  * the usual interface, but we typically only want one vibration at a time playing because they
27  * don't mix well. In order to synchronize the two places where vibration might be controlled,
28  * we provide this interface so the vibrator subsystem has a chance to:
29  *
30  * 1) Decide whether the current vibration should play based on the current system policy.
31  * 2) Stop any currently on-going vibrations.
32  * {@hide}
33  */
34 interface IExternalVibratorService {
35     const int SCALE_MUTE = -100;
36     const int SCALE_VERY_LOW = -2;
37     const int SCALE_LOW = -1;
38     const int SCALE_NONE = 0;
39     const int SCALE_HIGH = 1;
40     const int SCALE_VERY_HIGH = 2;
41 
42     /**
43      * A method called by the external system to start a vibration.
44      *
45      * If this returns {@code SCALE_MUTE}, then the vibration should <em>not</em> play. If this
46      * returns any other scale level, then any currently playing vibration controlled by the
47      * requesting system must be muted and this vibration can begin playback.
48      *
49      * Note that the IExternalVibratorService implementation will not call mute on any currently
50      * playing external vibrations in order to avoid re-entrancy with the system on the other side.
51      *
52      * @param vibration An ExternalVibration
53      *
54      * @return {@code SCALE_MUTE} if the external vibration should not play, and any other scale
55      *         level if it should.
56      */
onExternalVibrationStart(in ExternalVibration vib)57     int onExternalVibrationStart(in ExternalVibration vib);
58 
59     /**
60      * A method called by the external system when a vibration no longer wants to play.
61      */
onExternalVibrationStop(in ExternalVibration vib)62     void onExternalVibrationStop(in ExternalVibration vib);
63 }
64