Add SystemMonitor::GetMediaDevices()

base/system_monitor/system_monitor.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
 #define BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
 #pragma once
 
 #include <map>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/threading/thread_checker.h"
+#include "base/tuple.h"
 #include "build/build_config.h"
 
 // Windows HiRes timers drain the battery faster so we need to know the battery
 // status.  This isn't true for other platforms.
 #if defined(OS_WIN)
 #define ENABLE_BATTERY_MONITORING 1
 #else
 #undef ENABLE_BATTERY_MONITORING
 #endif  // !OS_WIN
 
@@ skipping 24 matching lines @@
   };
 
   enum PowerRequirement {
     DISPLAY_REQUIRED,   // The display should not be shut down.
     SYSTEM_REQUIRED,    // The system should not be suspended.
     CPU_REQUIRED,       // The process should not be suspended.
     TEST_REQUIRED       // This is used by unit tests.
   };
 
   typedef unsigned int DeviceIdType;
+  // (Media device id, Media device name, Media device path)
+  typedef Tuple3<DeviceIdType, std::string, FilePath> MediaDeviceInfo;
 
   // Create SystemMonitor. Only one SystemMonitor instance per application
   // is allowed.
   SystemMonitor();
   ~SystemMonitor();
 
   // Get the application-wide SystemMonitor (if not present, returns NULL).
   static SystemMonitor* Get();
 
 #if defined(OS_MACOSX)
@@ skipping 78 matching lines @@
   // Cross-platform handling of a power event.
   void ProcessPowerMessage(PowerEvent event_id);
 
   // Cross-platform handling of a device change event.
   void ProcessDevicesChanged();
   void ProcessMediaDeviceAttached(const DeviceIdType& id,
                                   const std::string& name,
                                   const FilePath& path);
   void ProcessMediaDeviceDetached(const DeviceIdType& id);
 
+  // Returns information for attached media devices.
+  std::vector<MediaDeviceInfo>* GetAttachedMediaDevices() const;
+
   // Enters or leaves a period of time with a given |requirement|. If the
   // operation has multiple requirements, make sure to use a unique |reason| for
   // each one. Reusing the same |reason| is OK as far as the |requirement| is
   // the same in every call, and each BeginPowerRequirement call is paired with
   // a call to EndPowerRequirement. |reason| is expected to be an ASCII string.
   // Must be called from the thread that created the SystemMonitor.
   // Warning: Please remember that sleep deprivation is not a good thing; use
   // with caution.
   void BeginPowerRequirement(PowerRequirement requirement,
                              const std::string& reason);
   void EndPowerRequirement(PowerRequirement requirement,
                            const std::string& reason);
 
   // Returns the number of outsanding power requirement requests.
   size_t GetPowerRequirementsCountForTest() const;
 
  private:
+  typedef std::map<base::SystemMonitor::DeviceIdType,
+                   MediaDeviceInfo> MediaDeviceMap;
 #if defined(OS_MACOSX)
   void PlatformInit();
   void PlatformDestroy();
 #endif
 
   // Platform-specific method to check whether the system is currently
   // running on battery power.  Returns true if running on batteries,
   // false otherwise.
   bool IsBatteryPower();
 
@@ skipping 19 matching lines @@
 
 #if defined(OS_WIN)
   std::map<std::string, std::pair<HANDLE, int> > handles_;
   base::ThreadChecker thread_checker_;
 #endif
 
 #if defined(ENABLE_BATTERY_MONITORING)
   base::OneShotTimer<SystemMonitor> delayed_battery_check_;
 #endif
 
+  MediaDeviceMap media_device_map_;
+
   DISALLOW_COPY_AND_ASSIGN(SystemMonitor);
 };
 
 }  // namespace base
 
 #endif  // BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_