1 // Copyright (c) 2012 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 #ifndef MEDIA_AUDIO_WIN_AUDIO_DEVICE_LISTENER_WIN_H_ 6 #define MEDIA_AUDIO_WIN_AUDIO_DEVICE_LISTENER_WIN_H_ 7 8 #include <MMDeviceAPI.h> 9 #include <string> 10 11 #include "base/basictypes.h" 12 #include "base/callback.h" 13 #include "base/threading/thread_checker.h" 14 #include "base/win/scoped_comptr.h" 15 #include "media/base/media_export.h" 16 17 using base::win::ScopedComPtr; 18 19 namespace media { 20 21 // IMMNotificationClient implementation for listening for default device changes 22 // and forwarding to AudioManagerWin so it can notify downstream clients. Only 23 // output (eRender) device changes are supported currently. Core Audio support 24 // is required to construct this object. Must be constructed and destructed on 25 // a single COM initialized thread. 26 // TODO(dalecurtis, henrika): Support input device changes. 27 class MEDIA_EXPORT AudioDeviceListenerWin : public IMMNotificationClient { 28 public: 29 // The listener callback will be called from a system level multimedia thread, 30 // thus the callee must be thread safe. |listener| is a permanent callback 31 // and must outlive AudioDeviceListenerWin. 32 explicit AudioDeviceListenerWin(const base::Closure& listener_cb); 33 virtual ~AudioDeviceListenerWin(); 34 35 private: 36 friend class AudioDeviceListenerWinTest; 37 38 // IMMNotificationClient implementation. 39 STDMETHOD_(ULONG, AddRef)(); 40 STDMETHOD_(ULONG, Release)(); 41 STDMETHOD(QueryInterface)(REFIID iid, void** object); 42 STDMETHOD(OnPropertyValueChanged)(LPCWSTR device_id, const PROPERTYKEY key); 43 STDMETHOD(OnDeviceAdded)(LPCWSTR device_id); 44 STDMETHOD(OnDeviceRemoved)(LPCWSTR device_id); 45 STDMETHOD(OnDeviceStateChanged)(LPCWSTR device_id, DWORD new_state); 46 STDMETHOD(OnDefaultDeviceChanged)(EDataFlow flow, ERole role, 47 LPCWSTR new_default_device_id); 48 49 base::Closure listener_cb_; 50 ScopedComPtr<IMMDeviceEnumerator> device_enumerator_; 51 std::string default_render_device_id_; 52 53 // AudioDeviceListenerWin must be constructed and destructed on one thread. 54 base::ThreadChecker thread_checker_; 55 56 DISALLOW_COPY_AND_ASSIGN(AudioDeviceListenerWin); 57 }; 58 59 } // namespace media 60 61 #endif // MEDIA_AUDIO_WIN_AUDIO_DEVICE_LISTENER_WIN_H_ 62
