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     /// <since_tizen> 3 </since_tizen>
  26     public class AudioVolume
  27     {
  28         private const string Tag = "Tizen.Multimedia.AudioVolume";
  29
  30         private int _volumeChangedCallbackId = -1;
  31         private EventHandler<VolumeChangedEventArgs> _volumeChanged;
  32         private Interop.AudioVolume.VolumeChangedCallback _volumeChangedCallback;
  33
  34         private object _eventLock = new object();
  35
  36         internal AudioVolume()
  37         {
  38             Level = new VolumeLevel();
  39             MaxLevel = new MaxVolumeLevel();
  40         }
  41
  42         /// <summary>
  43         /// Occurs when the volume level is changed.
  44         /// </summary>
  45         /// <since_tizen> 3 </since_tizen>
  46         public event EventHandler<VolumeChangedEventArgs> Changed
  47         {
  48             add
  49             {
  50                 lock (_eventLock)
  51                 {
  52                     if (_volumeChanged == null)
  53                     {
  54                         RegisterVolumeChangedEvent();
  55                     }
  56                     _volumeChanged += value;
  57                 }
  58             }
  59             remove
  60             {
  61                 if (value == null)
  62                 {
  63                     return;
  64                 }
  65
  66                 lock (_eventLock)
  67                 {
  68                     if (_volumeChanged == value)
  69                     {
  70                         UnregisterVolumeChangedEvent();
  71                     }
  72                     _volumeChanged -= value;
  73                 }
  74             }
  75         }
  76
  77         /// <summary>
  78         /// Gets the volume type of the sound being currently played.
  79         /// </summary>
  80         /// <value>The volume type of the sound being currently played.</value>
  81         /// <since_tizen> 3 </since_tizen>
  82         public AudioVolumeType CurrentPlaybackType
  83         {
  84             get
  85             {
  86                 var ret = Interop.AudioVolume.GetCurrentSoundType(out var currentType);
  87                 if (ret == AudioManagerError.NoPlayingSound)
  88                 {
  89                     return AudioVolumeType.None;
  90                 }
  91                 ret.Validate("Failed to get current volume type");
  92
  93                 return currentType;
  94             }
  95         }
  96
  97         /// <summary>
  98         /// Gets the <see cref="VolumeLevel"/>.
  99         /// </summary>
 100         /// <value>The <see cref="VolumeLevel"/>.</value>
 101         /// <since_tizen> 3 </since_tizen>
 102         public VolumeLevel Level { get; }
 103
 104         /// <summary>
 105         /// Gets the <see cref="MaxVolumeLevel"/>.
 106         /// </summary>
 107         /// <value>The <see cref="MaxVolumeLevel"/>.</value>
 108         /// <since_tizen> 3 </since_tizen>
 109         public MaxVolumeLevel MaxLevel { get; }
 110
 111         private void RegisterVolumeChangedEvent()
 112         {
 113             _volumeChangedCallback = (AudioVolumeType type, uint volume, IntPtr userData) =>
 114             {
 115                 _volumeChanged?.Invoke(this, new VolumeChangedEventArgs(type, volume));
 116             };
 117             var error = Interop.AudioVolume.AddVolumeChangedCallback(_volumeChangedCallback, IntPtr.Zero,
 118                 out _volumeChangedCallbackId);
 119             Log.Info(Tag, $"VolumeController callback id:{_volumeChangedCallbackId}");
 120
 121             error.Validate("Failed to add volume changed event");
 122         }
 123
 124         private void UnregisterVolumeChangedEvent()
 125         {
 126             Interop.AudioVolume.RemoveVolumeChangedCallback(_volumeChangedCallbackId).
 127                 Validate("Failed to remove volume changed event");
 128         }
 129     }
 130 }