content/public/browser/geolocation_provider.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 #ifndef CONTENT_PUBLIC_BROWSER_GEOLOCATION_PROVIDER_H_
   6 #define CONTENT_PUBLIC_BROWSER_GEOLOCATION_PROVIDER_H_
   7
   8 #include "base/callback_forward.h"
   9 #include "content/common/content_export.h"
  10
  11 namespace content {
  12 struct Geoposition;
  13
  14 class CONTENT_EXPORT GeolocationProvider {
  15  public:
  16   // This method, and all below, can only be called on the IO thread unless
  17   // otherwise specified.
  18   static GeolocationProvider* GetInstance();
  19
  20   typedef base::Callback<void(const Geoposition&)> LocationUpdateCallback;
  21
  22   // |use_high_accuracy| is used as a 'hint' for the provider preferences for
  23   // this particular observer, however the observer could receive updates for
  24   // best available locations from any active provider whilst it is registered.
  25   // If an existing observer is added a second time, its options are updated
  26   // but only a single call to RemoveLocationUpdateCallback() is required to
  27   // remove it.
  28   virtual void AddLocationUpdateCallback(const LocationUpdateCallback& callback,
  29                                          bool use_high_accuracy) = 0;
  30
  31   // Remove a previously registered observer. No-op if not previously registered
  32   // via AddLocationUpdateCallback(). Returns true if the observer was removed.
  33   virtual bool RemoveLocationUpdateCallback(
  34       const LocationUpdateCallback& callback) = 0;
  35
  36   // Calling this method indicates the user has opted into using location
  37   // services, including sending network requests to [Google servers to] resolve
  38   // the user's location. Use this method carefully, in line with the rules in
  39   // go/chrome-privacy-doc.
  40   virtual void UserDidOptIntoLocationServices() = 0;
  41
  42   // Overrides the current location for testing. This function may be called on
  43   // any thread. The completion callback will be invoked asynchronously on the
  44   // calling thread when the override operation is completed.
  45   //
  46   // This function allows the current location to be faked without having to
  47   // manually instantiate a GeolocationProvider backed by a MockLocationProvider
  48   // that serves a fake location.
  49   //
  50   // Do not use this function in unit tests. The function instantiates the
  51   // singleton geolocation stack in the background and manipulates it to report
  52   // a fake location. Neither step can be undone, breaking unit test isolation
  53   // (crbug.com/125931).
  54   static void OverrideLocationForTesting(
  55       const Geoposition& position,
  56       const base::Closure& completion_callback);
  57
  58  protected:
  59   virtual~GeolocationProvider() {}
  60 };
  61
  62 }  // namespace content
  63
  64 #endif  // CONTENT_PUBLIC_BROWSER_GEOLOCATION_PROVIDER_H_