src/Tizen.Network.Nfc/Tizen.Network.Nfc/NfcManagerEvent.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.Nfc
  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 NfcManagerImpl
  43     {
  44         private event EventHandler<ActivationChangedEventArgs> _activationChanged;
  45         private event EventHandler<NdefMessageDiscoveredEventArgs> _ndefMessageDiscovered;
  46
  47         private Interop.Nfc.ActivationChangedCallback _activationChangedCallback;
  48         private Interop.Nfc.NdefMessageDiscoveredCallback _ndefMessageDiscoveredCallback;
  49
  50         internal event EventHandler<ActivationChangedEventArgs> ActivationChanged
  51         {
  52             add
  53             {
  54                 if (_activationChanged == null)
  55                 {
  56                     RegisterActivationChangedEvent();
  57                 }
  58                 _activationChanged += value;
  59             }
  60             remove
  61             {
  62                 _activationChanged -= value;
  63                 if (_activationChanged == null)
  64                 {
  65                     UnregisterActivationChangedEvent();
  66                 }
  67             }
  68         }
  69
  70         internal event EventHandler<NdefMessageDiscoveredEventArgs> NdefMessageDiscovered
  71         {
  72             add
  73             {
  74                 if (_ndefMessageDiscovered == null)
  75                 {
  76                     RegisterNdefMessageDiscoveredEvent();
  77                 }
  78                 _ndefMessageDiscovered += value;
  79             }
  80             remove
  81             {
  82                 _ndefMessageDiscovered -= value;
  83                 if (_ndefMessageDiscovered == null)
  84                 {
  85                     UnregisterNdefMessageDiscoveredEvent();
  86                 }
  87             }
  88         }
  89
  90         internal void RemoveAllRegisteredEvent()
  91         {
  92             //unregister all remaining events when this object is released.
  93             if (_activationChanged != null)
  94             {
  95                 UnregisterActivationChangedEvent();
  96             }
  97         }
  98
  99         private void RegisterActivationChangedEvent()
 100         {
 101             _activationChangedCallback = (bool activated, IntPtr userData) =>
 102             {
 103                 bool isActivated = activated;
 104                 ActivationChangedEventArgs e = new ActivationChangedEventArgs(isActivated);
 105                 _activationChanged.SafeInvoke(null, e);
 106             };
 107             int ret = Interop.Nfc.SetActivationChangedCallback(_activationChangedCallback, IntPtr.Zero);
 108             if (ret != (int)NfcError.None)
 109             {
 110                 Log.Error(Globals.LogTag, "Failed to set activation changed callback, Error - " + (NfcError)ret);
 111             }
 112         }
 113
 114         private void UnregisterActivationChangedEvent()
 115         {
 116             Interop.Nfc.UnsetActivationChangedCallback();
 117         }
 118
 119         private void RegisterNdefMessageDiscoveredEvent()
 120         {
 121             _ndefMessageDiscoveredCallback = (IntPtr ndefMessageHandle, IntPtr userData) =>
 122             {
 123                 NdefMessageDiscoveredEventArgs e = new NdefMessageDiscoveredEventArgs(ndefMessageHandle);
 124                 _ndefMessageDiscovered.SafeInvoke(null, e);
 125             };
 126
 127             int ret = Interop.Nfc.SetNdefDiscoveredCallback(_ndefMessageDiscoveredCallback, IntPtr.Zero);
 128             if (ret != (int)NfcError.None)
 129             {
 130                 Log.Error(Globals.LogTag, "Failed to set ndef message discovered callback, Error - " + (NfcError)ret);
 131             }
 132         }
 133
 134         private void UnregisterNdefMessageDiscoveredEvent()
 135         {
 136             Interop.Nfc.UnsetNdefDiscoveredCallback();
 137         }
 138     }
 139 }