src/Tizen.Multimedia/AudioManager/AudioVolume.cs

   1 /*
   2  * Copyright (c) 2016 Samsung Electronics Co., Ltd All Rights Reserved
   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 using System;
  18
  19 namespace Tizen.Multimedia
  20 {
  21     /// <summary>
  22     /// Provides the ability to control the volume levels.
  23     /// </summary>
  24     /// <seealso cref="AudioManager"/>
  25     public class AudioVolume
  26     {
  27         private const string Tag = "Tizen.Multimedia.AudioVolume";
  28
  29         private int _volumeChangedCallbackId = -1;
  30         private EventHandler<VolumeChangedEventArgs> _volumeChanged;
  31         private Interop.AudioVolume.VolumeChangedCallback _volumeChangedCallback;
  32
  33         private object _eventLock = new object();
  34
  35         internal AudioVolume()
  36         {
  37             Level = new VolumeLevel();
  38             MaxLevel = new MaxVolumeLevel();
  39         }
  40
  41         /// <summary>
  42         /// Occurs when the volume level is changed.
  43         /// </summary>
  44         public event EventHandler<VolumeChangedEventArgs> Changed
  45         {
  46             add
  47             {
  48                 lock (_eventLock)
  49                 {
  50                     if (_volumeChanged == null)
  51                     {
  52                         RegisterVolumeChangedEvent();
  53                     }
  54                     _volumeChanged += value;
  55                 }
  56             }
  57             remove
  58             {
  59                 if (value == null)
  60                 {
  61                     return;
  62                 }
  63
  64                 lock (_eventLock)
  65                 {
  66                     if (_volumeChanged == value)
  67                     {
  68                         UnregisterVolumeChangedEvent();
  69                     }
  70                     _volumeChanged -= value;
  71                 }
  72             }
  73         }
  74
  75         /// <summary>
  76         /// Gets the volume type of the sound being currently played.
  77         /// </summary>
  78         /// <value>The volume type of the sound being currently played.</value>
  79         public AudioVolumeType CurrentPlaybackType
  80         {
  81             get
  82             {
  83                 var ret = Interop.AudioVolume.GetCurrentSoundType(out var currentType);
  84                 if (ret == AudioManagerError.NoPlayingSound)
  85                 {
  86                     return AudioVolumeType.None;
  87                 }
  88                 ret.Validate("Failed to get current volume type");
  89
  90                 return currentType;
  91             }
  92         }
  93
  94         /// <summary>
  95         /// Gets the <see cref="VolumeLevel"/>.
  96         /// </summary>
  97         /// <value>The <see cref="VolumeLevel"/>.</value>
  98         public VolumeLevel Level { get; }
  99
 100         /// <summary>
 101         /// Gets the <see cref="MaxVolumeLevel"/>.
 102         /// </summary>
 103         /// <value>The <see cref="MaxVolumeLevel"/>.</value>
 104         public MaxVolumeLevel MaxLevel { get; }
 105
 106         private void RegisterVolumeChangedEvent()
 107         {
 108             _volumeChangedCallback = (AudioVolumeType type, uint volume, IntPtr userData) =>
 109             {
 110                 _volumeChanged?.Invoke(this, new VolumeChangedEventArgs(type, volume));
 111             };
 112             var error = Interop.AudioVolume.AddVolumeChangedCallback(_volumeChangedCallback, IntPtr.Zero,
 113                 out _volumeChangedCallbackId);
 114             Log.Info(Tag, $"VolumeController callback id:{_volumeChangedCallbackId}");
 115
 116             error.Validate("Failed to add volume changed event");
 117         }
 118
 119         private void UnregisterVolumeChangedEvent()
 120         {
 121             Interop.AudioVolume.RemoveVolumeChangedCallback(_volumeChangedCallbackId).
 122                 Validate("Failed to remove volume changed event");
 123         }
 124     }
 125 }