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      1 /*
      2 **
      3 ** Copyright 2012, The Android Open Source Project
      4 **
      5 ** Licensed under the Apache License, Version 2.0 (the "License");
      6 ** you may not use this file except in compliance with the License.
      7 ** You may obtain a copy of the License at
      8 **
      9 **     http://www.apache.org/licenses/LICENSE-2.0
     10 **
     11 ** Unless required by applicable law or agreed to in writing, software
     12 ** distributed under the License is distributed on an "AS IS" BASIS,
     13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14 ** See the License for the specific language governing permissions and
     15 ** limitations under the License.
     16 */
     17 
     18 #ifndef ANDROID_AUDIO_HOTPLUG_THREAD_H
     19 #define ANDROID_AUDIO_HOTPLUG_THREAD_H
     20 
     21 #include <utils/threads.h>
     22 
     23 namespace android {
     24 
     25 class AudioHotplugThread : public Thread {
     26   public:
     27     struct DeviceInfo {
     28         unsigned int pcmCard;
     29         unsigned int pcmDevice;
     30         unsigned int minSampleBits, maxSampleBits;
     31         unsigned int minChannelCount, maxChannelCount;
     32         unsigned int minSampleRate, maxSampleRate;
     33         bool valid;
     34         bool forVoiceRecognition;
     35     };
     36 
     37     class Callback {
     38       public:
     39         virtual ~Callback() {}
     40         virtual void onDeviceFound(const DeviceInfo& devInfo) = 0;
     41         virtual void onDeviceRemoved(unsigned int pcmCard, unsigned int pcmDevice) = 0;
     42     };
     43 
     44     AudioHotplugThread(Callback& callback);
     45     virtual ~AudioHotplugThread();
     46 
     47     bool        start();
     48     void        shutdown();
     49 
     50   private:
     51     static const char* kThreadName;
     52     static const char* kAlsaDeviceDir;
     53     static const char  kDeviceTypeCapture;
     54     static bool parseCaptureDeviceName(const char *name, unsigned int *pcmCard,
     55                                        unsigned int *pcmDevice);
     56     static bool getDeviceInfo(unsigned int pcmCard, unsigned int pcmDevice,
     57                               DeviceInfo* info);
     58 
     59     virtual bool threadLoop();
     60 
     61     void scanForDevice();
     62 
     63     Callback& mCallback;
     64     int mShutdownEventFD;
     65 };
     66 
     67 }; // namespace android
     68 
     69 #endif  // ANDROID_AUDIO_HOTPLUG_THREAD_H
     70