src/Tizen.Network.Mtp/Tizen.Network.Mtp/MtpManagerEvent.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 using System.Threading.Tasks;
  19
  20 namespace Tizen.Network.Mtp
  21 {
  22     internal static class EventHandlerExtension
  23     {
  24         internal static void SafeInvoke(this EventHandler evt, object sender, EventArgs e)
  25         {
  26             var handler = evt;
  27             if (handler != null)
  28             {
  29                 handler(sender, e);
  30             }
  31         }
  32         internal static void SafeInvoke<T>(this EventHandler<T> evt, object sender, T e) where T : EventArgs
  33         {
  34             var handler = evt;
  35             if (handler != null)
  36             {
  37                 handler(sender, e);
  38             }
  39         }
  40     }
  41
  42     internal partial class MtpManagerImpl
  43     {
  44         private event EventHandler<MtpStateChangedEventArgs> _mtpStateChanged;
  45
  46         private Interop.Mtp.MptStateChangedCallback _mtpStateChangedCallback;
  47
  48         internal event EventHandler<MtpStateChangedEventArgs> MtpStateChanged
  49         {
  50             add
  51             {
  52                 if (_mtpStateChanged == null)
  53                 {
  54                     RegisterMtpStateChangedEvent();
  55                 }
  56                 _mtpStateChanged += value;
  57             }
  58             remove
  59             {
  60                 _mtpStateChanged -= value;
  61                 if (_mtpStateChanged == null)
  62                 {
  63                     UnregisterMtpStateChangedEvent();
  64                 }
  65             }
  66         }
  67
  68         private void RegisterMtpStateChangedEvent()
  69         {
  70             _mtpStateChangedCallback = (int eventType, int eventParameter, IntPtr userData) =>
  71             {
  72                 MtpEventType _eventType = (MtpEventType)eventType;
  73                 int _eventParameter = eventParameter;
  74                 MtpStateChangedEventArgs e = new MtpStateChangedEventArgs(_eventType, _eventParameter);
  75                 _mtpStateChanged.SafeInvoke(null, e);
  76             };
  77
  78             int ret = Interop.Mtp.AddMtpStateChangedCallback(_mtpStateChangedCallback, IntPtr.Zero);
  79             if (ret != (int)MtpError.None)
  80             {
  81                 Log.Error(Globals.LogTag, "Failed to add mtp state changed callback, Error - " + (MtpError)ret);
  82             }
  83         }
  84
  85         private void UnregisterMtpStateChangedEvent()
  86         {
  87             int ret = Interop.Mtp.RemoveMtpStateChangedCallback(_mtpStateChangedCallback);
  88
  89             if (ret != (int)MtpError.None)
  90             {
  91                 Log.Error(Globals.LogTag, "Failed to remove mtp state changed callback, Error - " + (MtpError)ret);
  92             }
  93         }
  94     }
  95 }