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      1 /*
      2  * Copyright 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 package com.android.media;
     17 
     18 import static android.media.VolumeProvider2.VOLUME_CONTROL_ABSOLUTE;
     19 import static android.media.VolumeProvider2.VOLUME_CONTROL_FIXED;
     20 import static android.media.VolumeProvider2.VOLUME_CONTROL_RELATIVE;
     21 
     22 import android.media.VolumeProvider2;
     23 import android.media.update.VolumeProvider2Provider;
     24 
     25 public class VolumeProvider2Impl implements VolumeProvider2Provider {
     26     private final VolumeProvider2 mInstance;
     27     private final int mControlType;
     28     private final int mMaxVolume;
     29 
     30     private int mCurrentVolume;
     31     private Callback mCallback;
     32 
     33     public VolumeProvider2Impl(VolumeProvider2 instance,
     34             @VolumeProvider2.ControlType int controlType, int maxVolume, int currentVolume) {
     35         if (controlType != VOLUME_CONTROL_FIXED && controlType != VOLUME_CONTROL_RELATIVE
     36                 && controlType != VOLUME_CONTROL_ABSOLUTE) {
     37             throw new IllegalArgumentException("wrong controlType " + controlType);
     38         }
     39         if (maxVolume < 0 || currentVolume < 0) {
     40             throw new IllegalArgumentException("volume shouldn't be negative"
     41                     + ", maxVolume=" + maxVolume + ", currentVolume=" + currentVolume);
     42         }
     43         if (currentVolume > maxVolume) {
     44             throw new IllegalArgumentException("currentVolume shouldn't be greater than maxVolume"
     45                     + ", maxVolume=" + maxVolume + ", currentVolume=" + currentVolume);
     46         }
     47         mInstance = instance;
     48         mControlType = controlType;
     49         mMaxVolume = maxVolume;
     50         mCurrentVolume = currentVolume;
     51     }
     52 
     53     @Override
     54     public int getControlType_impl() {
     55         return mControlType;
     56     }
     57 
     58     @Override
     59     public int getMaxVolume_impl() {
     60         return mMaxVolume;
     61     }
     62 
     63     @Override
     64     public int getCurrentVolume_impl() {
     65         return mCurrentVolume;
     66     }
     67 
     68     @Override
     69     public void setCurrentVolume_impl(int currentVolume) {
     70         if (currentVolume < 0) {
     71             throw new IllegalArgumentException("currentVolume shouldn't be negative"
     72                     + ", currentVolume=" + currentVolume);
     73         }
     74         mCurrentVolume = currentVolume;
     75         if (mCallback != null) {
     76             mCallback.onVolumeChanged(mInstance);
     77         }
     78     }
     79 
     80     /**
     81      * Sets a callback to receive volume changes.
     82      */
     83     public void setCallback(Callback callback) {
     84         mCallback = callback;
     85     }
     86 
     87     /**
     88      * Listens for changes to the volume.
     89      */
     90     public static abstract class Callback {
     91         public abstract void onVolumeChanged(VolumeProvider2 volumeProvider);
     92     }
     93 }
     94