chrome/browser/ui/webui/ntp/suggestions_combiner.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 #ifndef CHROME_BROWSER_UI_WEBUI_NTP_SUGGESTIONS_COMBINER_H_
   6 #define CHROME_BROWSER_UI_WEBUI_NTP_SUGGESTIONS_COMBINER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/scoped_vector.h"
  13
  14 class GURL;
  15 class SuggestionsHandler;
  16 class SuggestionsSource;
  17 class Profile;
  18
  19 namespace base {
  20 class DictionaryValue;
  21 class ListValue;
  22 }
  23
  24 // Combines many different sources of suggestions and generates data from it.
  25 class SuggestionsCombiner {
  26  public:
  27   // Interface to be implemented by classes that will be notified of events from
  28   // the SuggestionsCombiner.
  29   class Delegate {
  30    public:
  31     virtual ~Delegate() {}
  32
  33     // Method that is called when new suggestions are ready from the
  34     // SuggestionsCombiner.
  35     virtual void OnSuggestionsReady() = 0;
  36   };
  37
  38   virtual ~SuggestionsCombiner();
  39
  40   explicit SuggestionsCombiner(SuggestionsCombiner::Delegate* delegate,
  41                                Profile* profile);
  42
  43   // Add a new source. The SuggestionsCombiner takes ownership of |source|.
  44   void AddSource(SuggestionsSource* source);
  45
  46   // Enables or disables debug mode. If debug mode is enabled, the sources are
  47   // expected to provide additional data, which could be displayed, for example,
  48   // in the chrome://suggestions-internals/ page.
  49   void EnableDebug(bool enable);
  50
  51   // Fetch a new set of items from the various suggestion sources.
  52   void FetchItems(Profile* profile);
  53
  54   base::ListValue* GetPageValues();
  55
  56   // Called by a source when its items are ready. Make sure suggestion sources
  57   // call this method exactly once for each call to
  58   // SuggestionsSource::FetchItems.
  59   void OnItemsReady();
  60
  61   void SetSuggestionsCount(size_t suggestions_count);
  62
  63  private:
  64   friend class SuggestionsCombinerTest;
  65
  66   // Fill the page values from the suggestion sources so they can be sent to
  67   // the JavaScript side. This should only be called when all the suggestion
  68   // sources have items ready.
  69   void FillPageValues();
  70
  71   // Add extra information to page values that should be common across all
  72   // suggestion sources.
  73   void AddExtendedInformation(base::DictionaryValue* page_value);
  74
  75   // Checks if a URL is already open for the current profile. URLs open in an
  76   // incognito window are not reported.
  77   bool IsUrlAlreadyOpen(const GURL& url);
  78
  79   typedef ScopedVector<SuggestionsSource> SuggestionsSources;
  80
  81   // List of all the suggestions sources that will be combined to generate a
  82   // single list of suggestions.
  83   SuggestionsSources sources_;
  84
  85   // Counter tracking the number of sources that are currently asynchronously
  86   // fetching their data.
  87   int sources_fetching_count_;
  88
  89   // The delegate to notify once items are ready.
  90   SuggestionsCombiner::Delegate* delegate_;
  91
  92   // Number of suggestions to generate. Used to distribute the suggestions
  93   // between the various sources.
  94   size_t suggestions_count_;
  95
  96   // Informations to send to the javascript side.
  97   scoped_ptr<base::ListValue> page_values_;
  98
  99   // Whether debug mode is enabled or not (debug mode provides more data in the
 100   // results).
 101   bool debug_enabled_;
 102
 103   Profile* profile_;
 104
 105   DISALLOW_COPY_AND_ASSIGN(SuggestionsCombiner);
 106 };
 107
 108 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_SUGGESTIONS_COMBINER_H_