ui/app_list/search/mixer.h

   1 // Copyright 2013 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 UI_APP_LIST_SEARCH_MIXER_H_
   6 #define UI_APP_LIST_SEARCH_MIXER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/gtest_prod_util.h"
  12 #include "base/memory/scoped_vector.h"
  13 #include "ui/app_list/app_list_export.h"
  14 #include "ui/app_list/app_list_model.h"
  15 #include "ui/app_list/search/history_types.h"
  16
  17 namespace app_list {
  18
  19 namespace test {
  20 FORWARD_DECLARE_TEST(MixerTest, Publish);
  21 }
  22
  23 class SearchProvider;
  24 class SearchResult;
  25
  26 // Mixer collects results from providers, sorts them and publishes them to the
  27 // SearchResults UI model. The targeted results have 6 slots to hold the
  28 // result. The search controller can specify any number of groups, each with a
  29 // different number of results and priority boost. The "omnibox" group is
  30 // expected to contain omnibox results, and will be treated specially.
  31 class APP_LIST_EXPORT Mixer {
  32  public:
  33   explicit Mixer(AppListModel::SearchResults* ui_results);
  34   ~Mixer();
  35
  36   // Adds a new mixer group. A maximum of |max_results| results will be
  37   // displayed from this group (if 0, will allow unlimited results from this
  38   // group). Behaviour depends on the AppListMixer field trial:
  39   // - If default: Each result in the group will have its score boosted by
  40   //   |boost|. |multiplier| is ignored.
  41   // - If "Blended": |max_results| is a "soft" maximum; if there aren't enough
  42   //   results from all groups, more than |max_results| may be chosen from this
  43   //   group. Each result in the group will have its score multiplied by
  44   //   |multiplier|. |boost| is ignored.
  45   // Returns the group's group_id.
  46   size_t AddGroup(size_t max_results, double boost, double multiplier);
  47
  48   // Adds a new mixer group for the special "omnibox" group. This group will be
  49   // treated specially by the Mixer (it will be truncated such that it fills the
  50   // remaining slots without overflowing, but with at least one result). A
  51   // maximum of one group should be added using this method.
  52   size_t AddOmniboxGroup(size_t max_results, double boost, double multiplier);
  53
  54   // Associates a provider with a mixer group.
  55   void AddProviderToGroup(size_t group_id, SearchProvider* provider);
  56
  57   // Collects the results, sorts and publishes them.
  58   void MixAndPublish(bool is_voice_query, const KnownResults& known_results);
  59
  60  private:
  61   FRIEND_TEST_ALL_PREFIXES(test::MixerTest, Publish);
  62
  63   // Used for sorting and mixing results.
  64   struct APP_LIST_EXPORT SortData {
  65     SortData();
  66     SortData(SearchResult* result, double score);
  67
  68     bool operator<(const SortData& other) const;
  69
  70     SearchResult* result;  // Not owned.
  71     double score;
  72   };
  73   typedef std::vector<Mixer::SortData> SortedResults;
  74
  75   class Group;
  76   typedef ScopedVector<Group> Groups;
  77
  78   // Publishes the given |new_results| to |ui_results|, deleting any existing
  79   // results that are not in |new_results|. Results that already exist in
  80   // |ui_results| are reused to avoid flickering caused by icon reload.
  81   static void Publish(const SortedResults& results,
  82                       AppListModel::SearchResults* ui_results);
  83
  84   // Removes entries from |results| with duplicate IDs. When two or more results
  85   // have the same ID, the earliest one in the |results| list is kept.
  86   // NOTE: This is not necessarily the one with the highest *score*, as
  87   // |results| may not have been sorted yet.
  88   static void RemoveDuplicates(SortedResults* results);
  89
  90   void FetchResults(bool is_voice_query, const KnownResults& known_results);
  91
  92   AppListModel::SearchResults* ui_results_;  // Not owned.
  93   Groups groups_;
  94
  95   // The ID of the omnibox group. The group with this ID will be treated
  96   // specially by the Mixer. Ignored if the AppListMixer field trial is
  97   // "Blended".
  98   // TODO(mgiuca): Remove this after the field trial is complete.
  99   size_t omnibox_group_ = 0;
 100   // Whether |omnibox_group_| has been set.
 101   bool has_omnibox_group_ = false;
 102
 103   DISALLOW_COPY_AND_ASSIGN(Mixer);
 104 };
 105
 106 }  // namespace app_list
 107
 108 #endif  // UI_APP_LIST_SEARCH_MIXER_H_