Cleaner organization of WifiDataProvider code.

content/browser/geolocation/wifi_data_provider.h

 // Copyright 2013 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.
 
-// A wifi data provider provides wifi data from the device that is used by a
-// NetworkLocationProvider to obtain a position fix. We use a singleton
-// instance of the wifi data provider, which is used by multiple
-// NetworkLocationProvider objects.
-//
-// This file provides WifiDataProvider, which provides static methods to
-// access the singleton instance. The singleton instance uses a private
-// implementation to abstract across platforms and also to allow mock providers
-// to be used for testing.
-//
-// This file also provides WifiDataProviderImplBase, a base class which
-// provides common functionality for the private implementations.
-
 #ifndef CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_H_
 #define CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_H_
 
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_util.h"
 #include "content/browser/geolocation/wifi_data.h"
 #include "content/common/content_export.h"
 
 namespace content {
 
-class WifiDataProvider;
+class WifiDataProviderManager;
 
-// See class WifiDataProvider for the public client API.
-// WifiDataProvider uses containment to hide platform-specific implementation
-// details from common code. This class provides common functionality for these
-// contained implementation classes. This is a modified pimpl pattern.
-class CONTENT_EXPORT WifiDataProviderImplBase
-    : public base::RefCountedThreadSafe<WifiDataProviderImplBase> {
+class CONTENT_EXPORT WifiDataProvider
+    : public base::RefCountedThreadSafe<WifiDataProvider> {
  public:
-  WifiDataProviderImplBase();
+  WifiDataProvider();
 
   // Tells the provider to start looking for data. Callbacks will start
   // receiving notifications after this call.
   virtual void StartDataProvider() = 0;
 
   // Tells the provider to stop looking for data. Callbacks will stop
   // receiving notifications after this call.
   virtual void StopDataProvider() = 0;
 
   // Provides whatever data the provider has, which may be nothing. Return
   // value indicates whether this is all the data the provider could ever
   // obtain.
   virtual bool GetData(WifiData* data) = 0;
 
-  // Sets the container of this class, which is of type WifiDataProvider.
+  // Sets the container of this class, which is of type WifiDataProviderManager.
   // This is required to pass as a parameter when calling a callback.
-  void SetContainer(WifiDataProvider* container);
+  void SetContainer(WifiDataProviderManager* container);
 
-  typedef base::Callback<void(WifiDataProvider*)> WifiDataUpdateCallback;
+  typedef base::Callback<void(WifiDataProviderManager*)> WifiDataUpdateCallback;
 
   void AddCallback(WifiDataUpdateCallback* callback);
 
   bool RemoveCallback(WifiDataUpdateCallback* callback);
 
   bool has_callbacks() const;
 
  protected:
-  friend class base::RefCountedThreadSafe<WifiDataProviderImplBase>;
-  virtual ~WifiDataProviderImplBase();
+  friend class base::RefCountedThreadSafe<WifiDataProvider>;
+  virtual ~WifiDataProvider();
 
   typedef std::set<WifiDataUpdateCallback*> CallbackSet;
 
   // Runs all callbacks via a posted task, so we can unwind callstack here and
   // avoid client reentrancy.
   void RunCallbacks();
 
   bool CalledOnClientThread() const;
 
   base::MessageLoop* client_loop() const;
 
  private:
   void DoRunCallbacks();
 
-  WifiDataProvider* container_;
+  WifiDataProviderManager* container_;
 
   // Reference to the client's message loop. All callbacks should happen in this
   // context.
   base::MessageLoop* client_loop_;
 
   CallbackSet callbacks_;
 
-  DISALLOW_COPY_AND_ASSIGN(WifiDataProviderImplBase);
-};
-
-// A wifi data provider
-//
-// We use a singleton instance of this class which is shared by multiple network
-// location providers. These location providers access the instance through the
-// Register and Unregister methods.
-class CONTENT_EXPORT WifiDataProvider {
- public:
-  // Sets the factory function which will be used by Register to create the
-  // implementation used by the singleton instance. This factory approach is
-  // used both to abstract accross platform-specific implementations and to
-  // inject mock implementations for testing.
-  typedef WifiDataProviderImplBase* (*ImplFactoryFunction)(void);
-  static void SetFactory(ImplFactoryFunction factory_function_in);
-
-  // Resets the factory function to the default.
-  static void ResetFactory();
-
-  typedef base::Callback<void(WifiDataProvider*)> WifiDataUpdateCallback;
-
-  // Registers a callback, which will be run whenever new data is available.
-  // Instantiates the singleton if necessary, and always returns it.
-  static WifiDataProvider* Register(WifiDataUpdateCallback* callback);
-
-  // Removes a callback. If this is the last callback, deletes the singleton
-  // instance. Return value indicates success.
-  static bool Unregister(WifiDataUpdateCallback* callback);
-
-  // Provides whatever data the provider has, which may be nothing. Return
-  // value indicates whether this is all the data the provider could ever
-  // obtain.
-  bool GetData(WifiData* data);
-
- private:
-  // Private constructor and destructor, callers access singleton through
-  // Register and Unregister.
-  WifiDataProvider();
-  virtual ~WifiDataProvider();
-
-  void AddCallback(WifiDataUpdateCallback* callback);
-  bool RemoveCallback(WifiDataUpdateCallback* callback);
-  bool has_callbacks() const;
-
-  void StartDataProvider();
-  void StopDataProvider();
-
-  static WifiDataProviderImplBase* DefaultFactoryFunction();
-
-  // The singleton-like instance of this class. (Not 'true' singleton, as it
-  // may go through multiple create/destroy/create cycles per process instance,
-  // e.g. when under test).
-  static WifiDataProvider* instance_;
-
-  // The factory function used to create the singleton instance.
-  static ImplFactoryFunction factory_function_;
-
-  // The internal implementation.
-  scoped_refptr<WifiDataProviderImplBase> impl_;
-
   DISALLOW_COPY_AND_ASSIGN(WifiDataProvider);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_H_