[NTP Snippets] Refactor home-grown container API

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/sequenced_task_runner.h"
 #include "base/timer/timer.h"
 #include "components/keyed_service/core/keyed_service.h"
-#include "components/ntp_snippets/inner_iterator.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/suggestions/suggestions_service.h"
 
 class PrefRegistrySimple;
 class PrefService;
 class SkBitmap;
 
 namespace base {
 class Value;
 }
 
 namespace image_fetcher {
 class ImageFetcher;
 }
 
 namespace suggestions {
 class SuggestionsProfile;
 }
 
 namespace ntp_snippets {
 
 class NTPSnippetsServiceObserver;
 
 // Stores and vends fresh content data for the NTP.
 class NTPSnippetsService : public KeyedService {
  public:
   using NTPSnippetStorage = NTPSnippet::PtrVector;
-  using const_iterator =
-      InnerIterator<NTPSnippetStorage::const_iterator, const NTPSnippet>;
 
   using ImageFetchedCallback =
       base::Callback<void(const GURL&, const SkBitmap*)>;
 
   // |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(
       PrefService* pref_service,
@@ skipping 11 matching lines @@
 
   // Inherited from KeyedService.
   void Shutdown() override;
 
   // Fetches snippets from the server and adds them to the current ones.
   void FetchSnippets();
   // Fetches snippets from the server for specified hosts (overriding
   // suggestions from the suggestion service) and adds them to the current ones.
   void FetchSnippetsFromHosts(const std::set<std::string>& hosts);
 
+  // Available snippets.
+  const NTPSnippetStorage& snippets() const { return snippets_; }
+
+  // Returns the list of snippets previously discarded by the user (that are
+  // not expired yet).
+  const NTPSnippetStorage& discarded_snippets() const {
+    return discarded_snippets_;
+  }
+
   // Returns the last status message from the snippets fetcher.
   const std::string& last_status() const {
     return snippets_fetcher_->last_status();
   }
 
   // Returns the last json from the snippets fetcher.
   const std::string& last_json() const {
     return snippets_fetcher_->last_json();
   }
 
   // (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 given URL and notifies the observer afterwards.
   void FetchSnippetImage(const GURL& snippet_url,
                          const ImageFetchedCallback& callback);
 
   // Deletes all currently stored snippets.
   void ClearSnippets();
 
   // Discards the snippet with the given |url|, if it exists. Returns true iff
   // a snippet was discarded.
   bool DiscardSnippet(const GURL& url);
 
-  // Returns the list of snippets previously discarded by the user (that are
-  // not expired yet).
-  const NTPSnippetStorage& discarded_snippets() const {
-    return discarded_snippets_;
-  }
-
   // 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);
 
-  // Number of snippets available.
-  size_t size() const { return snippets_.size(); }
-
-  // The snippets can be iterated upon only via a const_iterator. Recommended
-  // way to iterate is as follows:
-  //
-  // NTPSnippetsService* service; // Assume is set.
-  //  for (auto& snippet : *service) {
-  //    // |snippet| here is a const object.
-  //  }
-  const_iterator begin() const { return const_iterator(snippets_.begin()); }
-  const_iterator end() const { return const_iterator(snippets_.end()); }
-
   // Returns the maximum number of snippets that will be shown at once.
   static int GetMaxSnippetCountForTesting();
 
  private:
   void OnSuggestionsChanged(const suggestions::SuggestionsProfile& suggestions);
   void OnFetchFinished(NTPSnippetsFetcher::OptionalSnippets snippets);
 
   // Expects a top-level dictionary containing a "recos" list, each element of
   // which will be parsed as a snippet.
   bool LoadFromFetchedValue(const base::Value& value);
@@ skipping 62 matching lines @@
   // Sent when the service is shutting down.
   virtual void NTPSnippetsServiceShutdown() = 0;
 
  protected:
   virtual ~NTPSnippetsServiceObserver() {}
 };
 
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_NTP_SNIPPETS_SERVICE_H_