📰 The Status card reports disabled sync states

components/ntp_snippets/ntp_snippets_service.h

 // Copyright 2015 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 COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_
 #define COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
-#include "base/scoped_observer.h"
 #include "base/timer/timer.h"
 #include "components/image_fetcher/image_fetcher_delegate.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/ntp_snippets/ntp_snippet.h"
 #include "components/ntp_snippets/ntp_snippets_fetcher.h"
 #include "components/ntp_snippets/ntp_snippets_scheduler.h"
+#include "components/ntp_snippets/ntp_snippets_status_service.h"
 #include "components/suggestions/suggestions_service.h"
 #include "components/sync_driver/sync_service_observer.h"
 
 class PrefRegistrySimple;
 class PrefService;
+class SigninManagerBase;
 
 namespace base {
 class RefCountedMemory;
 class Value;
 }
 
 namespace gfx {
 class Image;
 }
 
 namespace image_fetcher {
 class ImageDecoder;
 class ImageFetcher;
 }
 
 namespace suggestions {
 class SuggestionsProfile;
 }
 
 namespace sync_driver {
 class SyncService;
 }
 
 namespace ntp_snippets {
 
-enum class DisabledReason {
-  // Snippets are enabled
-  NONE,
-  // Snippets have been disabled as part of the service configuration.
-  EXPLICITLY_DISABLED,
-  // History sync is not enabled, and the service requires it to be enabled.
-  HISTORY_SYNC_DISABLED,
-  // The sync service is not completely initialized, and the status is unknown.
-  HISTORY_SYNC_STATE_UNKNOWN
-};
-
 class NTPSnippetsDatabase;
 class NTPSnippetsServiceObserver;
 
 // Stores and vends fresh content data for the NTP.
 class NTPSnippetsService : public KeyedService,
-                           public sync_driver::SyncServiceObserver,
                            public image_fetcher::ImageFetcherDelegate {
  public:
   using ImageFetchedCallback =
       base::Callback<void(const std::string& snippet_id, const gfx::Image&)>;
 
   // |application_language_code| should be a ISO 639-1 compliant string, e.g.
   // 'en' or 'en-US'. Note that this code should only specify the language, not
   // the locale, so 'en_US' (English language with US locale) and 'en-GB_US'
   // (British English person in the US) are not language codes.
   NTPSnippetsService(bool enabled,
                      PrefService* pref_service,
-                     sync_driver::SyncService* sync_service,
                      suggestions::SuggestionsService* suggestions_service,
                      const std::string& application_language_code,
                      NTPSnippetsScheduler* scheduler,
                      std::unique_ptr<NTPSnippetsFetcher> snippets_fetcher,
                      std::unique_ptr<image_fetcher::ImageFetcher> image_fetcher,
                      std::unique_ptr<image_fetcher::ImageDecoder> image_decoder,
-                     std::unique_ptr<NTPSnippetsDatabase> database);
+                     std::unique_ptr<NTPSnippetsDatabase> database,
+                     std::unique_ptr<NTPSnippetsStatusService> status_service);
+
   ~NTPSnippetsService() override;
 
   static void RegisterProfilePrefs(PrefRegistrySimple* registry);
 
   // Inherited from KeyedService.
   void Shutdown() override;
 
   // Returns whether the service is ready. While this is false, the list of
   // snippets will be empty, and all modifications to it (fetch, discard, etc)
   // will be ignored.
@@ skipping 17 matching lines @@
   // Returns the list of snippets previously discarded by the user (that are
   // not expired yet).
   const NTPSnippet::PtrVector& discarded_snippets() const {
     return discarded_snippets_;
   }
 
   const NTPSnippetsFetcher* snippets_fetcher() const {
     return snippets_fetcher_.get();
   }
 
+  // Returns a reason why the service is disabled, or DisabledReason::NONE
+  // if it's not.
+  DisabledReason disabled_reason() const {
+    return snippets_status_service_->disabled_reason();
+  }
+
   // (Re)schedules the periodic fetching of snippets. This is necessary because
   // the schedule depends on the time of day.
   void RescheduleFetching();
 
   // Fetches the image for the snippet with the given |snippet_id| and runs the
   // |callback|. If that snippet doesn't exist or the fetch fails, the callback
   // gets a null image.
   void FetchSnippetImage(const std::string& snippet_id,
                          const ImageFetchedCallback& callback);
 
   // Deletes all currently stored snippets.
   void ClearSnippets();
 
   // Discards the snippet with the given |snippet_id|, if it exists. Returns
   // true iff a snippet was discarded.
   bool DiscardSnippet(const std::string& snippet_id);
 
   // Clears the lists of snippets previously discarded by the user.
   void ClearDiscardedSnippets();
 
   // Returns the lists of suggestion hosts the snippets are restricted to.
   std::set<std::string> GetSuggestionsHosts() const;
 
   // Observer accessors.
   void AddObserver(NTPSnippetsServiceObserver* observer);
   void RemoveObserver(NTPSnippetsServiceObserver* observer);
 
-  // Returns a reason why the service could be disabled, or DisabledReason::NONE
-  // if it's not.
-  DisabledReason GetDisabledReason() const;
-
   // Returns the maximum number of snippets that will be shown at once.
   static int GetMaxSnippetCountForTesting();
 
  private:
-  FRIEND_TEST_ALL_PREFIXES(NTPSnippetsServiceTest, SyncStateCompatibility);
   FRIEND_TEST_ALL_PREFIXES(NTPSnippetsServiceTest, HistorySyncStateChanges);
 
   // Possible state transitions:
   //  +------- NOT_INITED ------+
   //  |        /       \        |
   //  |   READY <--> DISABLED <-+
   //  |       \        /
   //  +-----> SHUT_DOWN
   enum class State {
     // The service has just been created. Can change to states:
@@ skipping 18 matching lines @@
     // - READY: when the global Chrome state changes, for example after
     //          |OnStateChanged| is called and sync is enabled.
     // - SHUT_DOWN: when |Shutdown| is called, during the browser shutdown.
     DISABLED,
 
     // The service shutdown and can't be used anymore. This state is checked
     // for early exit in callbacks from observers.
     SHUT_DOWN
   };
 
-  // sync_driver::SyncServiceObserver implementation.
-  void OnStateChanged() override;
-
   // image_fetcher::ImageFetcherDelegate implementation.
   void OnImageDataFetched(const std::string& snippet_id,
                           const std::string& image_data) override;
 
   // Callbacks for the NTPSnippetsDatabase.
   void OnDatabaseLoaded(NTPSnippet::PtrVector snippets);
   void OnDatabaseError();
 
   // Callback for the SuggestionsService.
   void OnSuggestionsChanged(const suggestions::SuggestionsProfile& suggestions);
@@ skipping 21 matching lines @@
                                          const ImageFetchedCallback& callback,
                                          std::string data);
 
   void OnSnippetImageDecoded(const std::string& snippet_id,
                              const ImageFetchedCallback& callback,
                              const gfx::Image& image);
 
   void FetchSnippetImageFromNetwork(const std::string& snippet_id,
                                     const ImageFetchedCallback& callback);
 
-  // Returns whether the service should be enabled or disable depending on its
-  // internal state and the state of its dependencies.
-  State GetStateForDependenciesStatus();
+  // Triggers a state transition depending on the provided reason to be
+  // disabled (or lack thereof). This method is called when a change is detected
+  // by |snippets_status_service_|
+  void UpdateStateForStatus(DisabledReason disabled_reason);
 
   // Verifies state transitions (see |State|'s documentation) and applies them.
   // Does nothing if called with the current state.
   void EnterState(State state);
 
   // Enables the service and triggers a fetch if required. Do not call directly,
   // use |EnterState| instead.
   void EnterStateEnabled(bool fetch_snippets);
 
   // Disables the service. Do not call directly, use |EnterState| instead.
   void EnterStateDisabled();
 
   // Applies the effects of the transition to the SHUT_DOWN state. Do not call
   // directly, use |EnterState| instead.
   void EnterStateShutdown();
 
   void ClearDeprecatedPrefs();
 
   State state_;
 
-  // The service was set up to be disabled and should not be enabled by any
-  // state change. We track this to make sure we clear scheduled tasks, which
-  // persist even when Chrome is stopped.
-  bool explicitly_disabled_;
-
   PrefService* pref_service_;
 
-  sync_driver::SyncService* sync_service_;
-
-  // The observer for the SyncService. When the sync state changes,
-  // SyncService will call |OnStateChanged|, which is propagated to the
-  // snippet observers.
-  ScopedObserver<sync_driver::SyncService, sync_driver::SyncServiceObserver>
-      sync_service_observer_;
-
   suggestions::SuggestionsService* suggestions_service_;
 
   // All current suggestions (i.e. not discarded ones).
   NTPSnippet::PtrVector snippets_;
 
   // Suggestions that the user discarded. We keep these around until they expire
   // so we won't re-add them on the next fetch.
   NTPSnippet::PtrVector discarded_snippets_;
 
   // The ISO 639-1 code of the language used by the application.
@@ skipping 17 matching lines @@
 
   // Timer that calls us back when the next snippet expires.
   base::OneShotTimer expiry_timer_;
 
   std::unique_ptr<image_fetcher::ImageFetcher> image_fetcher_;
   std::unique_ptr<image_fetcher::ImageDecoder> image_decoder_;
 
   // The database for persisting snippets.
   std::unique_ptr<NTPSnippetsDatabase> database_;
 
+  // The service that provides events and data about the signin and sync state.
+  std::unique_ptr<NTPSnippetsStatusService> snippets_status_service_;
+
   // Set to true if FetchSnippets is called before the database has been loaded.
   // The fetch will be executed after the database load finishes.
   bool fetch_after_load_;
 
   DISALLOW_COPY_AND_ASSIGN(NTPSnippetsService);
 };
 
 class NTPSnippetsServiceObserver {
  public:
   // Sent every time the service loads a new set of data.
   virtual void NTPSnippetsServiceLoaded() = 0;
+
   // Sent when the service is shutting down.
   virtual void NTPSnippetsServiceShutdown() = 0;
-  // Sent when the service has been disabled. Can be from explicit user action
-  // or because a requirement (e.g. History Sync) is not fulfilled anymore.
-  virtual void NTPSnippetsServiceDisabled() = 0;
+
+  // Sent when the state of the service is changing. Something changed in its
+  // dependencies so it's notifying observers about incoming data changes.
+  // If the service might be enabled, DisabledReason::NONE will be provided.
+  virtual void NTPSnippetsServiceDisabledReasonChanged(DisabledReason) = 0;
 
  protected:
   virtual ~NTPSnippetsServiceObserver() {}
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_