Hooks together Geolocation Feature in the Client and Engine.

device/geolocation/location_arbitrator_impl.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef DEVICE_GEOLOCATION_LOCATION_ARBITRATOR_IMPL_H_
-#define DEVICE_GEOLOCATION_LOCATION_ARBITRATOR_IMPL_H_
-
-#include <stdint.h>
-#include <memory>
-#include <vector>
-
-#include "base/callback_forward.h"
-#include "base/cancelable_callback.h"
-#include "base/macros.h"
-#include "base/memory/scoped_vector.h"
-#include "base/strings/string16.h"
-#include "base/time/time.h"
-#include "device/geolocation/access_token_store.h"
-#include "device/geolocation/geolocation_export.h"
-#include "device/geolocation/geolocation_provider.h"
-#include "device/geolocation/geoposition.h"
-#include "device/geolocation/location_provider.h"
-#include "net/url_request/url_request_context_getter.h"
-
-namespace net {
-class URLRequestContextGetter;
-}
-
-namespace device {
-class AccessTokenStore;
-class GeolocationDelegate;
-class LocationProvider;
-
-// This class is responsible for handling updates from multiple underlying
-// providers and resolving them to a single 'best' location fix at any given
-// moment.
-class DEVICE_GEOLOCATION_EXPORT LocationArbitratorImpl
-    : public LocationProvider {
- public:
-  // Number of milliseconds newer a location provider has to be that it's worth
-  // switching to this location provider on the basis of it being fresher
-  // (regardles of relative accuracy). Public for tests.
-  static const int64_t kFixStaleTimeoutMilliseconds;
-
-  explicit LocationArbitratorImpl(GeolocationDelegate* delegate);
-  ~LocationArbitratorImpl() override;
-
-  static GURL DefaultNetworkProviderURL();
-  bool HasPermissionBeenGrantedForTest() const;
-
-  // LocationProvider implementation.
-  void SetUpdateCallback(
-      const LocationProviderUpdateCallback& callback) override;
-  bool StartProvider(bool enable_high_accuracy) override;
-  void StopProvider() override;
-  const Geoposition& GetPosition() override;
-  void OnPermissionGranted() override;
-
- protected:
-  // These functions are useful for injection of dependencies in derived
-  // testing classes.
-  virtual scoped_refptr<AccessTokenStore> NewAccessTokenStore();
-  virtual std::unique_ptr<LocationProvider> NewNetworkLocationProvider(
-      const scoped_refptr<AccessTokenStore>& access_token_store,
-      const scoped_refptr<net::URLRequestContextGetter>& context,
-      const GURL& url,
-      const base::string16& access_token);
-  virtual std::unique_ptr<LocationProvider> NewSystemLocationProvider();
-  virtual base::Time GetTimeNow() const;
-
- private:
-  friend class TestingLocationArbitrator;
-
-  scoped_refptr<AccessTokenStore> GetAccessTokenStore();
-
-  // Provider will either be added to |providers_| or
-  // deleted on error (e.g. it fails to start).
-  void RegisterProvider(std::unique_ptr<LocationProvider> provider);
-
-  void RegisterSystemProvider();
-  void OnAccessTokenStoresLoaded(
-      AccessTokenStore::AccessTokenMap access_token_map,
-      const scoped_refptr<net::URLRequestContextGetter>& context_getter);
-  bool DoStartProviders();
-
-  // Gets called when a provider has a new position.
-  void OnLocationUpdate(const LocationProvider* provider,
-                        const Geoposition& new_position);
-
-  // Returns true if |new_position| is an improvement over |old_position|.
-  // Set |from_same_provider| to true if both the positions came from the same
-  // provider.
-  bool IsNewPositionBetter(const Geoposition& old_position,
-                           const Geoposition& new_position,
-                           bool from_same_provider) const;
-
-  GeolocationDelegate* delegate_;
-
-  scoped_refptr<AccessTokenStore> access_token_store_;
-  LocationProvider::LocationProviderUpdateCallback arbitrator_update_callback_;
-
-  // The CancelableCallback will prevent OnAccessTokenStoresLoaded from being
-  // called multiple times by calling Reset() at the time of binding.
-  base::CancelableCallback<void(
-      AccessTokenStore::AccessTokenMap,
-      const scoped_refptr<net::URLRequestContextGetter>&)>
-      token_store_callback_;
-  std::vector<std::unique_ptr<LocationProvider>> providers_;
-  bool enable_high_accuracy_;
-  // The provider which supplied the current |position_|
-  const LocationProvider* position_provider_;
-  bool is_permission_granted_;
-  // The current best estimate of our position.
-  Geoposition position_;
-
-  // Tracks whether providers should be running.
-  bool is_running_;
-
-  DISALLOW_COPY_AND_ASSIGN(LocationArbitratorImpl);
-};
-
-// Factory functions for the various types of location provider to abstract
-// over the platform-dependent implementations.
-std::unique_ptr<LocationProvider> NewSystemLocationProvider();
-
-}  // namespace device
-
-#endif  // DEVICE_GEOLOCATION_LOCATION_ARBITRATOR_IMPL_H_