chrome/browser/autocomplete/zero_suggest_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 // This file contains the zero-suggest autocomplete provider. This experimental
   6 // provider is invoked when the user focuses in the omnibox prior to editing,
   7 // and generates search query suggestions based on the current URL.
   8
   9 #ifndef CHROME_BROWSER_AUTOCOMPLETE_ZERO_SUGGEST_PROVIDER_H_
  10 #define CHROME_BROWSER_AUTOCOMPLETE_ZERO_SUGGEST_PROVIDER_H_
  11
  12 #include "base/basictypes.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "chrome/browser/history/history_types.h"
  16 #include "components/metrics/proto/omnibox_event.pb.h"
  17 #include "components/omnibox/base_search_provider.h"
  18 #include "components/omnibox/search_provider.h"
  19 #include "net/url_request/url_fetcher_delegate.h"
  20
  21 class AutocompleteProviderListener;
  22 class Profile;
  23 class TemplateURLService;
  24
  25 namespace base {
  26 class ListValue;
  27 class Value;
  28 }
  29
  30 namespace net {
  31 class URLFetcher;
  32 }
  33
  34 namespace user_prefs {
  35 class PrefRegistrySyncable;
  36 }
  37
  38 // Autocomplete provider for searches based on the current URL.
  39 //
  40 // The controller will call StartZeroSuggest when the user focuses in the
  41 // omnibox. After construction, the autocomplete controller repeatedly calls
  42 // Start() with some user input, each time expecting to receive an updated
  43 // set of matches.
  44 //
  45 // TODO(jered): Consider deleting this class and building this functionality
  46 // into SearchProvider after dogfood and after we break the association between
  47 // omnibox text and suggestions.
  48 class ZeroSuggestProvider : public BaseSearchProvider,
  49                             public net::URLFetcherDelegate {
  50  public:
  51   // Creates and returns an instance of this provider.
  52   static ZeroSuggestProvider* Create(AutocompleteProviderListener* listener,
  53                                      TemplateURLService* template_url_service,
  54                                      Profile* profile);
  55
  56   // Registers a preference used to cache zero suggest results.
  57   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
  58
  59   // AutocompleteProvider:
  60   virtual void Start(const AutocompleteInput& input,
  61                      bool minimal_changes) OVERRIDE;
  62   virtual void Stop(bool clear_cached_results) OVERRIDE;
  63   virtual void DeleteMatch(const AutocompleteMatch& match) OVERRIDE;
  64   virtual void AddProviderInfo(ProvidersInfo* provider_info) const OVERRIDE;
  65
  66   // Sets |field_trial_triggered_| to false.
  67   virtual void ResetSession() OVERRIDE;
  68
  69  private:
  70   ZeroSuggestProvider(AutocompleteProviderListener* listener,
  71                       TemplateURLService* template_url_service,
  72                       Profile* profile);
  73
  74   virtual ~ZeroSuggestProvider();
  75
  76   // BaseSearchProvider:
  77   virtual const TemplateURL* GetTemplateURL(bool is_keyword) const OVERRIDE;
  78   virtual const AutocompleteInput GetInput(bool is_keyword) const OVERRIDE;
  79   virtual bool ShouldAppendExtraParams(
  80       const SearchSuggestionParser::SuggestResult& result) const OVERRIDE;
  81   virtual void RecordDeletionResult(bool success) OVERRIDE;
  82
  83   // net::URLFetcherDelegate:
  84   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  85
  86   // Optionally, cache the received |json_data| and return true if we want
  87   // to stop processing results at this point. The |parsed_data| is the parsed
  88   // version of |json_data| used to determine if we received an empty result.
  89   bool StoreSuggestionResponse(const std::string& json_data,
  90                                const base::Value& parsed_data);
  91
  92   // Adds AutocompleteMatches for each of the suggestions in |results| to
  93   // |map|.
  94   void AddSuggestResultsToMap(
  95       const SearchSuggestionParser::SuggestResults& results,
  96       MatchMap* map);
  97
  98   // Returns an AutocompleteMatch for a navigational suggestion |navigation|.
  99   AutocompleteMatch NavigationToMatch(
 100       const SearchSuggestionParser::NavigationResult& navigation);
 101
 102   // Fetches zero-suggest suggestions by sending a request using |suggest_url|.
 103   void Run(const GURL& suggest_url);
 104
 105   // Converts the parsed results to a set of AutocompleteMatches and adds them
 106   // to |matches_|.  Also update the histograms for how many results were
 107   // received.
 108   void ConvertResultsToAutocompleteMatches();
 109
 110   // Returns an AutocompleteMatch for the current URL. The match should be in
 111   // the top position so that pressing enter has the effect of reloading the
 112   // page.
 113   AutocompleteMatch MatchForCurrentURL();
 114
 115   // When the user is in the Most Visited field trial, we ask the TopSites
 116   // service for the most visited URLs during Run().  It calls back to this
 117   // function to return those |urls|.
 118   void OnMostVisitedUrlsAvailable(const history::MostVisitedURLList& urls);
 119
 120   // Returns the relevance score for the verbatim result.
 121   int GetVerbatimRelevance() const;
 122
 123   // Whether we can show zero suggest on |current_page_url| without
 124   // sending |current_page_url| as a parameter to the server at |suggest_url|.
 125   bool CanShowZeroSuggestWithoutSendingURL(const GURL& suggest_url,
 126                                            const GURL& current_page_url) const;
 127
 128   // Checks whether we have a set of zero suggest results cached, and if so
 129   // populates |matches_| with cached results.
 130   void MaybeUseCachedSuggestions();
 131
 132   AutocompleteProviderListener* listener_;
 133   Profile* profile_;
 134
 135   // The URL for which a suggestion fetch is pending.
 136   std::string current_query_;
 137
 138   // The type of page the user is viewing (a search results page doing search
 139   // term replacement, an arbitrary URL, etc.).
 140   metrics::OmniboxEventProto::PageClassification current_page_classification_;
 141
 142   // Copy of OmniboxEditModel::permanent_text_.
 143   base::string16 permanent_text_;
 144
 145   // Fetcher used to retrieve results.
 146   scoped_ptr<net::URLFetcher> fetcher_;
 147
 148   // Suggestion for the current URL.
 149   AutocompleteMatch current_url_match_;
 150
 151   // Contains suggest and navigation results as well as relevance parsed from
 152   // the response for the most recent zero suggest input URL.
 153   SearchSuggestionParser::Results results_;
 154
 155   // Whether we are currently showing cached zero suggest results.
 156   bool results_from_cache_;
 157
 158   history::MostVisitedURLList most_visited_urls_;
 159
 160   // For callbacks that may be run after destruction.
 161   base::WeakPtrFactory<ZeroSuggestProvider> weak_ptr_factory_;
 162
 163   DISALLOW_COPY_AND_ASSIGN(ZeroSuggestProvider);
 164 };
 165
 166 #endif  // CHROME_BROWSER_AUTOCOMPLETE_ZERO_SUGGEST_PROVIDER_H_