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 #ifndef CONTENT_PUBLIC_BROWSER_GEOLOCATION_PROVIDER_H_ 6 #define CONTENT_PUBLIC_BROWSER_GEOLOCATION_PROVIDER_H_ 7 8 #include "base/callback_list.h" 9 #include "content/common/content_export.h" 10 11 namespace content { 12 struct Geoposition; 13 14 // This is the main API to the geolocation subsystem. The application will hold 15 // a single instance of this class and can register multiple clients to be 16 // notified of location changes: 17 // * Callbacks are registered by AddLocationUpdateCallback() and will keep 18 // receiving updates until the returned subscription object is destructed. 19 // The application must instantiate the GeolocationProvider on the UI thread and 20 // must communicate with it on the same thread. 21 // The underlying location arbitrator will only be enabled whilst there is at 22 // least one registered observer or pending callback (and only after 23 // UserDidOptIntoLocationServices). The arbitrator and the location providers it 24 // uses run on a separate Geolocation thread. 25 class GeolocationProvider { 26 public: 27 CONTENT_EXPORT static GeolocationProvider* GetInstance(); 28 29 typedef base::Callback<void(const Geoposition&)> LocationUpdateCallback; 30 typedef base::CallbackList<void(const Geoposition&)>::Subscription 31 Subscription; 32 33 // |use_high_accuracy| is used as a 'hint' for the provider preferences for 34 // this particular observer, however the observer could receive updates for 35 // best available locations from any active provider whilst it is registered. 36 virtual scoped_ptr<Subscription> AddLocationUpdateCallback( 37 const LocationUpdateCallback& callback, bool use_high_accuracy) = 0; 38 39 // Calling this method indicates the user has opted into using location 40 // services, including sending network requests to [Google servers to] resolve 41 // the user's location. Use this method carefully, in line with the rules in 42 // go/chrome-privacy-doc. 43 virtual void UserDidOptIntoLocationServices() = 0; 44 45 // Overrides the current location for testing. 46 // 47 // Overrides the location for automation/testing. Suppresses any further 48 // updates from the actual providers and sends an update with the overridden 49 // position to all registered clients. 50 // 51 // Do not use this function in unit tests. The function instantiates the 52 // singleton geolocation stack in the background and manipulates it to report 53 // a fake location. Neither step can be undone, breaking unit test isolation 54 // (crbug.com/125931). 55 virtual void OverrideLocationForTesting(const Geoposition& position) = 0; 56 57 protected: 58 virtual~GeolocationProvider() {} 59 }; 60 61 } // namespace content 62 63 #endif // CONTENT_PUBLIC_BROWSER_GEOLOCATION_PROVIDER_H_ 64
