1 // Copyright 2014 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 // A wifi data provider provides wifi data from the device that is used by a 6 // NetworkLocationProvider to obtain a position fix. We use a singleton 7 // instance of the wifi data provider manager, which is used by multiple 8 // NetworkLocationProvider objects. 9 // 10 // This file provides WifiDataProviderManager, which provides static methods to 11 // access the singleton instance. The singleton instance uses a private 12 // implementation of WifiDataProvider to abstract across platforms and also to 13 // allow mock providers to be used for testing. 14 15 #ifndef CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_MANAGER_H_ 16 #define CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_MANAGER_H_ 17 18 #include <set> 19 20 #include "base/basictypes.h" 21 #include "base/bind.h" 22 #include "base/callback.h" 23 #include "base/memory/ref_counted.h" 24 #include "base/message_loop/message_loop.h" 25 #include "base/strings/string16.h" 26 #include "base/strings/string_util.h" 27 #include "content/browser/geolocation/wifi_data.h" 28 #include "content/common/content_export.h" 29 30 namespace content { 31 32 class WifiDataProvider; 33 34 // A manager for wifi data providers. 35 // 36 // We use a singleton instance of this class which is shared by multiple network 37 // location providers. These location providers access the instance through the 38 // Register and Unregister methods. 39 class CONTENT_EXPORT WifiDataProviderManager { 40 public: 41 typedef WifiDataProvider* (*ImplFactoryFunction)(void); 42 43 // Sets the factory function which will be used by Register to create the 44 // implementation used by the singleton instance. This factory approach is 45 // used both to abstract accross platform-specific implementations and to 46 // inject mock implementations for testing. 47 static void SetFactoryForTesting(ImplFactoryFunction factory_function_in); 48 49 // Resets the factory function to the default. 50 static void ResetFactoryForTesting(); 51 52 typedef base::Closure WifiDataUpdateCallback; 53 54 // Registers a callback, which will be run whenever new data is available. 55 // Instantiates the singleton if necessary, and always returns it. 56 static WifiDataProviderManager* Register(WifiDataUpdateCallback* callback); 57 58 // Removes a callback. If this is the last callback, deletes the singleton 59 // instance. Return value indicates success. 60 static bool Unregister(WifiDataUpdateCallback* callback); 61 62 // Provides whatever data the provider has, which may be nothing. Return 63 // value indicates whether this is all the data the provider could ever 64 // obtain. 65 bool GetData(WifiData* data); 66 67 private: 68 // Private constructor and destructor, callers access singleton through 69 // Register and Unregister. 70 WifiDataProviderManager(); 71 ~WifiDataProviderManager(); 72 73 void AddCallback(WifiDataUpdateCallback* callback); 74 bool RemoveCallback(WifiDataUpdateCallback* callback); 75 bool has_callbacks() const; 76 77 void StartDataProvider(); 78 void StopDataProvider(); 79 80 static WifiDataProvider* DefaultFactoryFunction(); 81 82 // The singleton-like instance of this class. (Not 'true' singleton, as it 83 // may go through multiple create/destroy/create cycles per process instance, 84 // e.g. when under test). 85 static WifiDataProviderManager* instance_; 86 87 // The factory function used to create the singleton instance. 88 static ImplFactoryFunction factory_function_; 89 90 // The internal implementation. 91 scoped_refptr<WifiDataProvider> impl_; 92 93 DISALLOW_COPY_AND_ASSIGN(WifiDataProviderManager); 94 }; 95 96 } // namespace content 97 98 #endif // CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_MANAGER_H_ 99