content/browser/geolocation/gps_location_provider_linux.h

   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 // This file declares GPS providers that run on linux. Currently, just uses
   6 // the libgps (gpsd) API. Public for testing only - for normal usage this
   7 // header should not be required, as location_provider.h declares the needed
   8 // factory function.
   9
  10 #ifndef CONTENT_BROWSER_GEOLOCATION_GPS_LOCATION_PROVIDER_LINUX_H_
  11 #define CONTENT_BROWSER_GEOLOCATION_GPS_LOCATION_PROVIDER_LINUX_H_
  12
  13 #include "base/compiler_specific.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/weak_ptr.h"
  16 #include "content/browser/geolocation/location_provider.h"
  17 #include "content/common/content_export.h"
  18 #include "content/public/common/geoposition.h"
  19
  20 struct gps_data_t;
  21
  22 namespace content {
  23
  24 // Defines a wrapper around the C libgps API (gps.h). Similar to the libgpsmm.h
  25 // API provided by that package.
  26 class CONTENT_EXPORT LibGps {
  27  public:
  28   virtual ~LibGps();
  29   // Attempts to dynamically load the libgps.so library and returns NULL on
  30   // failure.
  31   static LibGps* New();
  32
  33   bool Start();
  34   void Stop();
  35   bool Read(content::Geoposition* position);
  36
  37  protected:
  38   typedef int (*gps_open_fn)(const char*, const char*, struct gps_data_t*);
  39   typedef int (*gps_close_fn)(struct gps_data_t*);
  40   typedef int (*gps_read_fn)(struct gps_data_t*);
  41
  42   explicit LibGps(void* dl_handle,
  43                   gps_open_fn gps_open,
  44                   gps_close_fn gps_close,
  45                   gps_read_fn gps_read);
  46
  47   // Returns false if there is no fix available.
  48   virtual bool GetPositionIfFixed(content::Geoposition* position);
  49
  50  private:
  51 #if defined(USE_LIBGPS)
  52   void* dl_handle_;
  53   gps_open_fn gps_open_;
  54   gps_close_fn gps_close_;
  55   gps_read_fn gps_read_;
  56
  57   scoped_ptr<gps_data_t> gps_data_;
  58   bool is_open_;
  59 #endif  // defined(USE_LIBGPS)
  60
  61   DISALLOW_COPY_AND_ASSIGN(LibGps);
  62 };
  63
  64 // Location provider for Linux, that uses libgps/gpsd to obtain position fixes.
  65 // TODO(joth): Currently this runs entirely in the client thread (i.e. Chrome's
  66 // IO thread). As the older libgps API is not designed to support polling,
  67 // there's a chance it could block, so better move this into its own worker
  68 // thread.
  69 class CONTENT_EXPORT GpsLocationProviderLinux : public LocationProviderBase {
  70  public:
  71   typedef LibGps* (*LibGpsFactory)();
  72   // |factory| will be used to create the gpsd client library wrapper. (Note
  73   // NewSystemLocationProvider() will use the default factory).
  74   explicit GpsLocationProviderLinux(LibGpsFactory libgps_factory);
  75   virtual ~GpsLocationProviderLinux();
  76
  77   void SetGpsdReconnectIntervalMillis(int value) {
  78     gpsd_reconnect_interval_millis_ = value;
  79   }
  80   void SetPollPeriodMovingMillis(int value) {
  81     poll_period_moving_millis_ = value;
  82   }
  83   void SetPollPeriodStationaryMillis(int value) {
  84     poll_period_stationary_millis_ = value;
  85   }
  86
  87   // LocationProvider
  88   virtual bool StartProvider(bool high_accuracy) OVERRIDE;
  89   virtual void StopProvider() OVERRIDE;
  90   virtual void GetPosition(Geoposition* position) OVERRIDE;
  91   virtual void UpdatePosition() OVERRIDE;
  92
  93  private:
  94   // Task which run in the child thread.
  95   void DoGpsPollTask();
  96
  97   // Will schedule a poll; i.e. enqueue DoGpsPollTask deferred task.
  98   void ScheduleNextGpsPoll(int interval);
  99
 100   int gpsd_reconnect_interval_millis_;
 101   int poll_period_moving_millis_;
 102   int poll_period_stationary_millis_;
 103
 104   const LibGpsFactory libgps_factory_;
 105   scoped_ptr<LibGps> gps_;
 106   Geoposition position_;
 107
 108   // Holder for the tasks which run on the thread; takes care of cleanup.
 109   base::WeakPtrFactory<GpsLocationProviderLinux> weak_factory_;
 110 };
 111
 112 }  // namespace content
 113
 114 #endif  // CONTENT_BROWSER_GEOLOCATION_GPS_LOCATION_PROVIDER_LINUX_H_