content/browser/geolocation/win7_location_api_win.cc

   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 #include "content/browser/geolocation/win7_location_api_win.h"
   6
   7 #include "base/base_paths_win.h"
   8 #include "base/command_line.h"
   9 #include "base/file_path.h"
  10 #include "base/logging.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/path_service.h"
  13 #include "content/public/common/content_switches.h"
  14 #include "content/public/common/geoposition.h"
  15
  16 namespace content {
  17 namespace {
  18 const double kKnotsToMetresPerSecondConversionFactor = 0.5144;
  19
  20 void ConvertKnotsToMetresPerSecond(double* knots) {
  21   *knots *= kKnotsToMetresPerSecondConversionFactor;
  22 }
  23
  24 HINSTANCE LoadWin7Library(const string16& lib_name) {
  25   FilePath sys_dir;
  26   PathService::Get(base::DIR_SYSTEM, &sys_dir);
  27   return LoadLibrary(sys_dir.Append(lib_name).value().c_str());
  28 }
  29 }
  30
  31 Win7LocationApi::Win7LocationApi()
  32     : prop_lib_(0),
  33       PropVariantToDouble_function_(0),
  34       locator_(0) {
  35 }
  36
  37 void Win7LocationApi::Init(HINSTANCE prop_library,
  38     PropVariantToDoubleFunction PropVariantToDouble_function,
  39     ILocation* locator) {
  40   prop_lib_ = prop_library;
  41   PropVariantToDouble_function_ = PropVariantToDouble_function;
  42   locator_ = locator;
  43 }
  44
  45 Win7LocationApi::~Win7LocationApi() {
  46   if (prop_lib_ != NULL)
  47     FreeLibrary(prop_lib_);
  48 }
  49
  50 Win7LocationApi* Win7LocationApi::Create() {
  51   if (!CommandLine::ForCurrentProcess()
  52       ->HasSwitch(switches::kExperimentalLocationFeatures))
  53     return NULL;
  54
  55   scoped_ptr<Win7LocationApi> result(new Win7LocationApi);
  56   // Load probsys.dll
  57   string16 lib_needed = L"propsys.dll";
  58   HINSTANCE prop_lib = LoadWin7Library(lib_needed);
  59   if (!prop_lib)
  60     return NULL;
  61   // Get pointer to function.
  62   PropVariantToDoubleFunction PropVariantToDouble_function;
  63   PropVariantToDouble_function =
  64       reinterpret_cast<PropVariantToDoubleFunction>(
  65           GetProcAddress(prop_lib, "PropVariantToDouble"));
  66   if (!PropVariantToDouble_function) {
  67     FreeLibrary(prop_lib);
  68     return NULL;
  69   }
  70   // Create the ILocation object that receives location reports.
  71   HRESULT result_type;
  72   CComPtr<ILocation> locator;
  73   result_type = CoCreateInstance(
  74       CLSID_Location, NULL, CLSCTX_INPROC, IID_PPV_ARGS(&locator));
  75   if (!SUCCEEDED(result_type)) {
  76     FreeLibrary(prop_lib);
  77     return NULL;
  78   }
  79   IID reports_needed[] = { IID_ILatLongReport };
  80   result_type = locator->RequestPermissions(NULL, reports_needed, 1, TRUE);
  81   result->Init(prop_lib, PropVariantToDouble_function, locator);
  82   return result.release();
  83 }
  84
  85 Win7LocationApi* Win7LocationApi::CreateForTesting(
  86     PropVariantToDoubleFunction PropVariantToDouble_function,
  87     ILocation* locator) {
  88   Win7LocationApi* result = new Win7LocationApi;
  89   result->Init(NULL, PropVariantToDouble_function, locator);
  90   return result;
  91 }
  92
  93 void Win7LocationApi::GetPosition(Geoposition* position) {
  94   DCHECK(position);
  95   position->error_code = Geoposition::ERROR_CODE_POSITION_UNAVAILABLE;
  96   if (!locator_)
  97     return;
  98   // Try to get a position fix
  99   if (!GetPositionIfFixed(position))
 100     return;
 101   position->error_code = Geoposition::ERROR_CODE_NONE;
 102   if (!position->Validate()) {
 103     // GetPositionIfFixed returned true, yet we've not got a valid fix.
 104     // This shouldn't happen; something went wrong in the conversion.
 105     NOTREACHED() << "Invalid position from GetPositionIfFixed: lat,long "
 106                  << position->latitude << "," << position->longitude
 107                  << " accuracy " << position->accuracy << " time "
 108                  << position->timestamp.ToDoubleT();
 109     position->error_code = Geoposition::ERROR_CODE_POSITION_UNAVAILABLE;
 110     position->error_message = "Bad fix from Win7 provider";
 111   }
 112 }
 113
 114 bool Win7LocationApi::GetPositionIfFixed(Geoposition* position) {
 115   HRESULT result_type;
 116   CComPtr<ILocationReport> location_report;
 117   CComPtr<ILatLongReport> lat_long_report;
 118   result_type = locator_->GetReport(IID_ILatLongReport, &location_report);
 119   // Checks to see if location access is allowed.
 120   if (result_type == E_ACCESSDENIED)
 121     position->error_code = Geoposition::ERROR_CODE_PERMISSION_DENIED;
 122   // Checks for any other errors while requesting a location report.
 123   if (!SUCCEEDED(result_type))
 124     return false;
 125   result_type = location_report->QueryInterface(&lat_long_report);
 126   if (!SUCCEEDED(result_type))
 127     return false;
 128   result_type = lat_long_report->GetLatitude(&position->latitude);
 129   if (!SUCCEEDED(result_type))
 130     return false;
 131   result_type = lat_long_report->GetLongitude(&position->longitude);
 132   if (!SUCCEEDED(result_type))
 133     return false;
 134   result_type = lat_long_report->GetErrorRadius(&position->accuracy);
 135   if (!SUCCEEDED(result_type) || position->accuracy <= 0)
 136     return false;
 137   double temp_dbl;
 138   result_type = lat_long_report->GetAltitude(&temp_dbl);
 139   if (SUCCEEDED(result_type))
 140     position->altitude = temp_dbl;
 141   result_type = lat_long_report->GetAltitudeError(&temp_dbl);
 142   if (SUCCEEDED(result_type))
 143     position->altitude_accuracy = temp_dbl;
 144   PROPVARIANT heading;
 145   PropVariantInit(&heading);
 146   result_type = lat_long_report->GetValue(
 147       SENSOR_DATA_TYPE_TRUE_HEADING_DEGREES, &heading);
 148   if (SUCCEEDED(result_type))
 149     PropVariantToDouble_function_(heading, &position->heading);
 150   PROPVARIANT speed;
 151   PropVariantInit(&speed);
 152   result_type = lat_long_report->GetValue(
 153       SENSOR_DATA_TYPE_SPEED_KNOTS, &speed);
 154   if (SUCCEEDED(result_type)) {
 155     PropVariantToDouble_function_(speed, &position->speed);
 156     ConvertKnotsToMetresPerSecond(&position->speed);
 157   }
 158   position->timestamp = base::Time::Now();
 159   return true;
 160 }
 161
 162 bool Win7LocationApi::SetHighAccuracy(bool acc) {
 163   HRESULT result_type;
 164   result_type = locator_->SetDesiredAccuracy(IID_ILatLongReport,
 165       acc ? LOCATION_DESIRED_ACCURACY_HIGH :
 166             LOCATION_DESIRED_ACCURACY_DEFAULT);
 167   return SUCCEEDED(result_type);
 168 }
 169
 170 }  // namespace content