device/nfc/nfc_adapter_factory.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "device/nfc/nfc_adapter_factory.h"
   6
   7 #include "base/lazy_instance.h"
   8 #include "base/logging.h"
   9 #include "base/memory/weak_ptr.h"
  10
  11 #if defined(OS_CHROMEOS)
  12 #include "device/nfc/nfc_adapter_chromeos.h"
  13 #endif
  14
  15 namespace device {
  16
  17 namespace {
  18
  19 // Shared default adapter instance, we don't want to keep this class around
  20 // if nobody is using it so use a WeakPtr and create the object when needed;
  21 // since Google C++ Style (and clang's static analyzer) forbids us having
  22 // exit-time destructors we use a leaky lazy instance for it.
  23 base::LazyInstance<base::WeakPtr<device::NfcAdapter> >::Leaky
  24     default_adapter = LAZY_INSTANCE_INITIALIZER;
  25
  26 }  // namespace
  27
  28 // static
  29 bool NfcAdapterFactory::IsNfcAvailable() {
  30 #if defined(OS_CHROMEOS)
  31   return true;
  32 #else
  33   return false;
  34 #endif
  35 }
  36
  37 // static
  38 void NfcAdapterFactory::GetAdapter(const AdapterCallback&  callback) {
  39   if (!IsNfcAvailable()) {
  40     LOG(WARNING) << "NFC is not available on the current platform.";
  41     return;
  42   }
  43   if (!default_adapter.Get().get()) {
  44 #if defined(OS_CHROMEOS)
  45     chromeos::NfcAdapterChromeOS* new_adapter =
  46         new chromeos::NfcAdapterChromeOS();
  47     default_adapter.Get() = new_adapter->weak_ptr_factory_.GetWeakPtr();
  48 #endif
  49   }
  50   if (default_adapter.Get()->IsInitialized())
  51     callback.Run(scoped_refptr<NfcAdapter>(default_adapter.Get().get()));
  52 }
  53
  54 }  // namespace device